#!/usr/bin/env python3
"""
Chapter 3: Wound Healing and Tissue Repair
Comprehensive PDF generator with simplified explanations, flowcharts, and embedded figures.
"""

import urllib.request
import os
from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm, mm
from reportlab.lib.colors import (
    HexColor, white, black, Color
)
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    PageBreak, KeepTogether, HRFlowable, Image as RLImage
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus.flowables import Flowable
from io import BytesIO

# ── colour palette ──────────────────────────────────────────────────────────
C_SALMON   = HexColor("#E8735A")   # chapter heading
C_DARK     = HexColor("#2C3E50")   # body text / dark heading
C_BOX_BG   = HexColor("#FAF0ED")   # summary box background
C_BOX_BORD = HexColor("#D4846A")   # summary box border
C_FLOW_BG  = HexColor("#3D8EB9")   # flowchart box fill (blue)
C_FLOW_BG2 = HexColor("#E8735A")   # flowchart box fill (salmon)
C_FLOW_BG3 = HexColor("#2ECC71")   # flowchart box fill (green)
C_FLOW_BG4 = HexColor("#8E44AD")   # flowchart box fill (purple)
C_TBL_HEAD = HexColor("#C0392B")   # table header
C_TBL_ALT  = HexColor("#FDECEA")   # table alt row
C_LIGHT_BLUE = HexColor("#EBF5FB") # light blue bg
C_LIGHT_SALMON = HexColor("#FDEBD0")

PAGE_W, PAGE_H = A4
L_MARGIN = 2*cm
R_MARGIN = 2*cm
T_MARGIN = 2*cm
B_MARGIN = 2*cm

OUTPUT = "/home/daytona/workspace/wound-healing-pdf/Wound_Healing_and_Tissue_Repair.pdf"

# ── image URLs ───────────────────────────────────────────────────────────────
IMAGE_URLS = {
    "img01": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0017-1783005751475-spykuy.jpg",
    "img02": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0014-1783005751498-uj66x0.jpg",
    "img03": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0015-1783005751495-7v8qu3.jpg",
    "img04": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0013-1783005751563-0ijt19.jpg",
    "img05": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0012-1783005751486-pkqa0g.jpg",
    "img06": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0016-1783005751571-ms400j.jpg",
    "img07": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0020-1783005751574-fikz4m.jpg",
    "img08": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0018-1783005751567-cvnora.jpg",
    "img09": "https://d361swluvexzqs.cloudfront.net/chats-attachments/IMG-20260702-WA0019-1783005751504-sbguus.jpg",
}

# Download images
IMG_DIR = "/home/daytona/workspace/wound-healing-pdf/imgs"
os.makedirs(IMG_DIR, exist_ok=True)
downloaded = {}
for key, url in IMAGE_URLS.items():
    path = f"{IMG_DIR}/{key}.jpg"
    try:
        urllib.request.urlretrieve(url, path)
        downloaded[key] = path
        print(f"Downloaded {key}")
    except Exception as e:
        print(f"Failed {key}: {e}")

# ── styles ────────────────────────────────────────────────────────────────────
styles = getSampleStyleSheet()

def S(name, **kw):
    return ParagraphStyle(name, **kw)

sty_chapter = S("chapter",
    fontName="Helvetica-Bold", fontSize=28, textColor=C_SALMON,
    spaceAfter=6, leading=34)

sty_chapter_sub = S("chapter_sub",
    fontName="Helvetica", fontSize=14, textColor=C_DARK,
    spaceAfter=16, leading=18)

sty_h1 = S("h1",
    fontName="Helvetica-Bold", fontSize=16, textColor=C_SALMON,
    spaceBefore=18, spaceAfter=6, leading=20)

sty_h2 = S("h2",
    fontName="Helvetica-Bold", fontSize=13, textColor=C_DARK,
    spaceBefore=14, spaceAfter=4, leading=17)

sty_h3 = S("h3",
    fontName="Helvetica-Bold", fontSize=11, textColor=C_DARK,
    spaceBefore=10, spaceAfter=3, leading=15)

sty_body = S("body",
    fontName="Helvetica", fontSize=10, textColor=C_DARK,
    spaceAfter=6, leading=15, alignment=TA_JUSTIFY)

sty_bullet = S("bullet",
    fontName="Helvetica", fontSize=10, textColor=C_DARK,
    leftIndent=18, firstLineIndent=-12, spaceAfter=3, leading=14,
    bulletIndent=6)

sty_subbullet = S("subbullet",
    fontName="Helvetica", fontSize=9.5, textColor=C_DARK,
    leftIndent=30, firstLineIndent=-12, spaceAfter=2, leading=13)

sty_caption = S("caption",
    fontName="Helvetica-Oblique", fontSize=9, textColor=C_DARK,
    spaceAfter=10, spaceBefore=4, leading=13, alignment=TA_CENTER)

sty_box_title = S("box_title",
    fontName="Helvetica-Bold", fontSize=11, textColor=C_SALMON,
    spaceAfter=4, leading=14)

sty_box_body = S("box_body",
    fontName="Helvetica", fontSize=9.5, textColor=C_DARK,
    leftIndent=10, spaceAfter=3, leading=13)

sty_flow = S("flow",
    fontName="Helvetica-Bold", fontSize=9.5, textColor=white,
    alignment=TA_CENTER, leading=13)

sty_flow_dark = S("flow_dark",
    fontName="Helvetica-Bold", fontSize=9.5, textColor=C_DARK,
    alignment=TA_CENTER, leading=13)

sty_tbl_hdr = S("tbl_hdr",
    fontName="Helvetica-Bold", fontSize=9.5, textColor=white,
    alignment=TA_CENTER, leading=12)

sty_tbl_cell = S("tbl_cell",
    fontName="Helvetica", fontSize=9, textColor=C_DARK,
    leading=12)

sty_note = S("note",
    fontName="Helvetica-Oblique", fontSize=9, textColor=HexColor("#666666"),
    spaceAfter=4, leading=12, alignment=TA_CENTER)

# ── helper functions ──────────────────────────────────────────────────────────

def B(txt): return f"<b>{txt}</b>"
def I(txt): return f"<i>{txt}</i>"

def H1(txt): return Paragraph(txt, sty_h1)
def H2(txt): return Paragraph(txt, sty_h2)
def H3(txt): return Paragraph(txt, sty_h3)
def P(txt):  return Paragraph(txt, sty_body)
def Bul(txt, indent=0):
    style = sty_bullet if indent==0 else sty_subbullet
    return Paragraph(f"• {txt}", style)
def Cap(txt): return Paragraph(txt, sty_caption)
def SP(n=6): return Spacer(1, n)
def HR(): return HRFlowable(width="100%", thickness=1, color=C_BOX_BORD, spaceAfter=6, spaceBefore=6)

def embed_image(key, width=14*cm, caption=None):
    items = []
    if key in downloaded:
        try:
            img = RLImage(downloaded[key], width=width, kind='proportional')
            items.append(img)
        except:
            items.append(P(f"[Image: {key}]"))
    else:
        items.append(P(f"[Image unavailable: {key}]"))
    if caption:
        items.append(Cap(caption))
    return items

def box(title, content_items, bg=C_BOX_BG, border=C_BOX_BORD):
    """Wrap content in a coloured summary box using a single-cell table."""
    inner = [Paragraph(title, sty_box_title)] + content_items
    t = Table([[inner]], colWidths=[PAGE_W - L_MARGIN - R_MARGIN - 0.4*cm])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), bg),
        ('BOX', (0,0), (-1,-1), 1.5, border),
        ('LEFTPADDING', (0,0), (-1,-1), 10),
        ('RIGHTPADDING', (0,0), (-1,-1), 10),
        ('TOPPADDING', (0,0), (-1,-1), 8),
        ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ]))
    return t

def flow_arrow(): return Paragraph("▼", S("arr", fontName="Helvetica-Bold", fontSize=14,
    textColor=C_DARK, alignment=TA_CENTER, spaceAfter=2, spaceBefore=2))

def flow_box(text, color=C_FLOW_BG, text_style=None):
    st = text_style or sty_flow
    inner = Paragraph(text, st)
    t = Table([[inner]], colWidths=[PAGE_W - L_MARGIN - R_MARGIN - 0.4*cm])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), color),
        ('BOX', (0,0), (-1,-1), 1.5, color),
        ('LEFTPADDING', (0,0), (-1,-1), 12),
        ('RIGHTPADDING', (0,0), (-1,-1), 12),
        ('TOPPADDING', (0,0), (-1,-1), 7),
        ('BOTTOMPADDING', (0,0), (-1,-1), 7),
        ('ROUNDEDCORNERS', (0,0), (-1,-1), 6),
    ]))
    return t

def flow_box_narrow(text, color=C_FLOW_BG, width=8*cm, text_style=None):
    st = text_style or sty_flow
    inner = Paragraph(text, st)
    t = Table([[inner]], colWidths=[width])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), color),
        ('BOX', (0,0), (-1,-1), 1.5, color),
        ('LEFTPADDING', (0,0), (-1,-1), 8),
        ('RIGHTPADDING', (0,0), (-1,-1), 8),
        ('TOPPADDING', (0,0), (-1,-1), 6),
        ('BOTTOMPADDING', (0,0), (-1,-1), 6),
    ]))
    return t

def side_by_side(left_items, right_items):
    """Place two lists of flowables side by side in a 2-col table."""
    col_w = (PAGE_W - L_MARGIN - R_MARGIN - 0.5*cm) / 2
    t = Table([[left_items, right_items]], colWidths=[col_w, col_w])
    t.setStyle(TableStyle([
        ('VALIGN', (0,0), (-1,-1), 'TOP'),
        ('LEFTPADDING', (0,0), (-1,-1), 4),
        ('RIGHTPADDING', (0,0), (-1,-1), 4),
        ('TOPPADDING', (0,0), (-1,-1), 0),
        ('BOTTOMPADDING', (0,0), (-1,-1), 0),
    ]))
    return t

# ── build story ───────────────────────────────────────────────────────────────

story = []

# ════════════════════════════════════════════════════════════════════════════
# COVER / TITLE
# ════════════════════════════════════════════════════════════════════════════
story += [
    SP(40),
    Paragraph("CHAPTER 3", S("ch_label", fontName="Helvetica-Bold", fontSize=13,
        textColor=C_SALMON, alignment=TA_CENTER, spaceAfter=6)),
    Paragraph("Wound Healing and Tissue Repair",
        S("cover_title", fontName="Helvetica-Bold", fontSize=32, textColor=C_DARK,
          alignment=TA_CENTER, spaceAfter=12, leading=40)),
    SP(6),
    HR(),
    SP(10),
    Paragraph("A Plain-English Study Guide", S("sub", fontName="Helvetica-Oblique",
        fontSize=14, textColor=HexColor("#666666"), alignment=TA_CENTER, spaceAfter=30)),
    SP(20),
]

# Learning objectives box
lo_items = [
    Bul("Understand normal wound healing and what can go wrong"),
    Bul("Know the different types of healing and how to classify wounds"),
    Bul("Understand the principles of wound management"),
    Bul("Understand the principles of scar management"),
]
story.append(box("🎯  Learning Objectives", lo_items))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 1: INTRODUCTION
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("1.  Introduction"),
    P("Wound healing is one of the most complex biological processes in the human body. "
      "When you get injured, your body works hard to repair the damage — but in adults, this "
      "almost always leaves a scar (called <b>fibrosis</b>). Scar tissue can cause problems "
      "because it is not as good as normal tissue."),
    P("Interestingly, early fetal tissue (before birth) can heal <i>without</i> forming scars. "
      "This is why scientists are very interested in regenerative medicine — the idea of making "
      "adult wounds heal the way fetal wounds do."),
    SP(6),
]

# ════════════════════════════════════════════════════════════════════════════
# SECTION 2: NORMAL WOUND HEALING IN SKIN
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("2.  Normal Wound Healing in Skin"),
    P("Wound healing in skin goes through <b>three main overlapping stages</b> (sometimes "
      "four, if you include haemostasis as a separate first step):"),
    SP(4),
]

# Phase overview flowchart
story += [
    flow_box("STAGE 0: HAEMOSTASIS (immediate — seconds to minutes)", C_FLOW_BG2),
    flow_arrow(),
    flow_box("STAGE 1: INFLAMMATION (Days 1–3)", C_FLOW_BG),
    flow_arrow(),
    flow_box("STAGE 2: PROLIFERATION (Days 3 – 2 to 4 weeks)", C_FLOW_BG3),
    flow_arrow(),
    flow_box("STAGE 3: REMODELLING (2–3 weeks — 1+ year)", C_FLOW_BG4),
    SP(12),
]

# Embed Figure 3.1
story += embed_image("img02", width=14*cm,
    caption="Figure 3.1 — Classic stages of wound healing: (a) Inflammation, "
            "(b) Proliferation, (c) Remodelling. Each diagram shows a cross-section "
            "of skin layers (epidermis, dermis, subcutaneous). In (a) a V-shaped cut "
            "is visible with a fibrin clot, bacteria, platelets and neutrophils. "
            "In (b) a scab (eschar) covers granulation tissue with new blood vessels. "
            "In (c) the epidermis is restored and dense parallel collagen fibres fill the dermis.")
story.append(SP(10))

# ── 2.1 Haemostasis ──────────────────────────────────────────────────────────
story += [
    H2("2.1  Stage 0 — Haemostasis (Stop the Bleeding!)"),
    P("The moment a blood vessel is damaged, the body immediately tries to stop bleeding. "
      "This happens in two steps:"),
    Bul("<b>Vasoconstriction:</b> The broken blood vessel squeezes shut to slow blood flow."),
    Bul("<b>Platelet plug:</b> Platelets (tiny blood cells) stick to the exposed collagen "
        "in the vessel wall, activate each other, and clump together to form a plug that "
        "blocks the hole."),
    SP(4),
    P("Once platelets activate, they release chemical packets (granules) full of growth "
      "factors and cytokines — these are chemical messengers that kickstart all the later "
      "stages of healing. Important ones include:"),
    Bul("TGF-β (Transforming Growth Factor Beta)"),
    Bul("PDGF (Platelet-Derived Growth Factor)"),
    Bul("FGF (Fibroblast Growth Factor)"),
    Bul("EGF (Epidermal Growth Factor)"),
    Bul("VEGF (Vascular Endothelial Growth Factor)"),
    SP(6),
    P("At the same time, the <b>coagulation cascade</b> is triggered — a chain reaction "
      "of proteins in the blood that ultimately creates <b>thrombin</b>, which converts "
      "fibrinogen into <b>fibrin</b>. Fibrin forms a mesh that strengthens the platelet "
      "plug into a proper clot (a scaffold for the next stages)."),
    SP(6),
]

# Coagulation cascade flowchart
story += [
    H3("Simplified Coagulation Cascade Flowchart"),
    SP(4),
    flow_box("TWO ENTRY POINTS:", HexColor("#555555"), text_style=sty_flow),
    SP(4),
]

coa_data = [
    [Paragraph("INTRINSIC PATHWAY\n(Contact System)\nTriggered inside blood vessels", sty_flow),
     Paragraph("EXTRINSIC PATHWAY\nTriggered by tissue damage\n(Tissue Factor released)", sty_flow)],
    [Paragraph("▼", S("a", fontName="Helvetica-Bold", fontSize=14, textColor=C_DARK, alignment=TA_CENTER)),
     Paragraph("▼", S("a", fontName="Helvetica-Bold", fontSize=14, textColor=C_DARK, alignment=TA_CENTER))],
    [Paragraph("FXII → FXIIa\nFXI → FXIa\nFIX → FIXa", sty_flow),
     Paragraph("FVII → FVIIa\n(activated by tissue factor)", sty_flow)],
    [Paragraph("▼", S("a", fontName="Helvetica-Bold", fontSize=14, textColor=C_DARK, alignment=TA_CENTER)),
     Paragraph("▼", S("a", fontName="Helvetica-Bold", fontSize=14, textColor=C_DARK, alignment=TA_CENTER))],
    [Paragraph("Both pathways converge ↓", S("cv", fontName="Helvetica-BoldOblique", fontSize=10,
        textColor=C_SALMON, alignment=TA_CENTER)),
     Paragraph("Both pathways converge ↓", S("cv2", fontName="Helvetica-BoldOblique", fontSize=10,
        textColor=C_SALMON, alignment=TA_CENTER))],
]
col_w = (PAGE_W - L_MARGIN - R_MARGIN - 0.5*cm) / 2
coa_t = Table(coa_data, colWidths=[col_w, col_w])
coa_t.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (0,0), C_FLOW_BG),
    ('BACKGROUND', (1,0), (1,0), C_FLOW_BG2),
    ('BACKGROUND', (0,2), (0,2), C_FLOW_BG),
    ('BACKGROUND', (1,2), (1,2), C_FLOW_BG2),
    ('BACKGROUND', (0,4), (1,4), C_LIGHT_SALMON),
    ('BOX', (0,0), (0,0), 1, C_FLOW_BG),
    ('BOX', (1,0), (1,0), 1, C_FLOW_BG2),
    ('BOX', (0,2), (0,2), 1, C_FLOW_BG),
    ('BOX', (1,2), (1,2), 1, C_FLOW_BG2),
    ('LEFTPADDING', (0,0), (-1,-1), 8),
    ('RIGHTPADDING', (0,0), (-1,-1), 8),
    ('TOPPADDING', (0,0), (-1,-1), 6),
    ('BOTTOMPADDING', (0,0), (-1,-1), 6),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('ALIGN', (0,0), (-1,-1), 'CENTER'),
]))
story.append(coa_t)
story.append(flow_arrow())
story.append(flow_box("COMMON PATHWAY: FX → FXa → Prothrombin (FII) → Thrombin (FIIa)", C_FLOW_BG3))
story.append(flow_arrow())
story.append(flow_box("Fibrinogen → FIBRIN CLOT (cross-linked by Factor XIII)", C_FLOW_BG2))
story.append(SP(6))
story.append(P("<i>Note: Fibrinolysis (clot breakdown) starts simultaneously — plasmin dissolves the fibrin "
               "once healing is underway, preventing permanent clotting.</i>"))
story.append(SP(6))

story += embed_image("img02", width=13*cm,
    caption="Figure 3.2 — The coagulation cascade. Blue arrows = common pathway. "
            "Red arrows = intrinsic (contact) pathway. Black arrows = extrinsic pathway. "
            "Green arrows = fibrinolysis (clot breakdown). Both pathways converge to produce "
            "thrombin, which converts fibrinogen to fibrin.")
story.append(SP(10))

# ── 2.2 Inflammation ─────────────────────────────────────────────────────────
story += [
    H2("2.2  Stage 1 — Inflammation (Clean-Up Crew, Days 1–3)"),
    P("Inflammation is the body's defence response to injury. It is visible as <b>redness, "
      "swelling, warmth and pain</b> (in Latin: <i>rubor, tumor, calor, dolor</i>)."),
    SP(4),
]

inflam_flow = [
    flow_box("DAY 1–2: Early Inflammation", C_FLOW_BG2),
    SP(4),
    P("• Platelet activation causes an influx of <b>neutrophils</b> (a type of white blood cell "
      "with a multi-lobed nucleus).<br/>"
      "• Neutrophils are the first responders — they kill bacteria by engulfing them.<br/>"
      "• Histamine and serotonin are released, making blood vessels leakier so more immune "
      "cells can get to the wound."),
    SP(4),
    flow_arrow(),
    flow_box("DAY 2–3: Late Inflammation", C_FLOW_BG),
    SP(4),
    P("• <b>Monocytes</b> (another white blood cell type) arrive and become <b>macrophages</b>.<br/>"
      "• Macrophages are the 'clean-up crew' — they eat dead tissue and bacteria (phagocytosis).<br/>"
      "• They also release growth factors and cytokines that stimulate the next phase."),
]
for item in inflam_flow:
    story.append(item)
story.append(SP(8))

# ── 2.3 Proliferation ────────────────────────────────────────────────────────
story += [
    H2("2.3  Stage 2 — Proliferation (Building New Tissue, Day 3 – 4 Weeks)"),
    P("This is when the wound physically fills in with new tissue. There are four key processes:"),
    SP(4),
]

prolif_data = [
    [Paragraph("Process", sty_tbl_hdr), Paragraph("What happens", sty_tbl_hdr),
     Paragraph("Key cells", sty_tbl_hdr)],
    [Paragraph("1. Ground substance production", sty_tbl_cell),
     Paragraph("Fibroblasts make glycosaminoglycans and proteoglycans — the 'glue' that holds the new tissue together", sty_tbl_cell),
     Paragraph("Fibroblasts", sty_tbl_cell)],
    [Paragraph("2. Collagen production", sty_tbl_cell),
     Paragraph("Fibroblasts lay down collagen fibres to give the wound structural strength", sty_tbl_cell),
     Paragraph("Fibroblasts", sty_tbl_cell)],
    [Paragraph("3. Angiogenesis", sty_tbl_cell),
     Paragraph("New blood vessels grow into the wound (gives granulation tissue its pink colour)", sty_tbl_cell),
     Paragraph("Endothelial cells", sty_tbl_cell)],
    [Paragraph("4. Re-epithelialisation", sty_tbl_cell),
     Paragraph("Skin cells (epithelial cells) migrate from the edges to cover the surface", sty_tbl_cell),
     Paragraph("Keratinocytes", sty_tbl_cell)],
]
col_ws = [4.5*cm, 8.5*cm, 3.5*cm]
pt = Table(prolif_data, colWidths=col_ws)
pt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(pt)
story += [
    SP(6),
    P("The wound tissue formed in the early part of this phase is called <b>granulation tissue</b> "
      "— it is pink and granular-looking. Later, some fibroblasts turn into <b>myofibroblasts</b> "
      "(contractile cells that pull wound edges together)."),
    SP(8),
]

# ── 2.4 Remodelling ──────────────────────────────────────────────────────────
story += [
    H2("2.4  Stage 3 — Remodelling (Fine-Tuning, 2 Weeks – 1+ Year)"),
    P("The wound has now closed but the collagen inside is disorganised. During remodelling:"),
    Bul("Weak <b>Type III collagen</b> (the quick-fix type) is gradually replaced by stronger "
        "<b>Type I collagen</b>."),
    Bul("Collagen fibres become more cross-linked and aligned in parallel — like wooden planks "
        "being laid straight."),
    Bul("The normal skin ratio of 4:1 (Type I : Type III) is re-established."),
    Bul("Maximum tensile strength (~80% of normal skin) is reached at about <b>12 weeks</b>."),
    Bul("A scar never reaches 100% of the original skin strength."),
    SP(10),
]

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 3: NORMAL HEALING IN OTHER TISSUES
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("3.  Normal Healing in Other Specific Tissues"),
]

# ── 3.1 Bone ─────────────────────────────────────────────────────────────────
story += [
    H2("3.1  Bone Healing"),
    P("Bone heals similarly to skin — through stages of inflammation, repair, and remodelling — "
      "but with some important differences. Most fractures heal by forming a <b>callus</b> "
      "(a bridge of new bone tissue)."),
    SP(4),
]

bone_flow = [
    flow_box("STEP 1 — Haematoma Formation\nBlood collects at the fracture site → inflammation begins", C_FLOW_BG2),
    flow_arrow(),
    flow_box("STEP 2 — Soft Callus\nFibrocartilage fills the gap (soft, rubbery bridge)", C_FLOW_BG),
    flow_arrow(),
    flow_box("STEP 3 — Hard Callus\nCartilage is converted to woven bone (hard callus) by osteoblasts", C_FLOW_BG3),
    flow_arrow(),
    flow_box("STEP 4 — Remodelling\nOsteoclasts remove excess bone; osteoblasts lay lamellar bone → normal shape restored", C_FLOW_BG4),
    SP(6),
]
for item in bone_flow:
    story.append(item)

story += embed_image("img02", width=14*cm,
    caption="Figure 3.3 — Stages of bone healing: (a) haematoma + inflammation, "
            "(b) soft callus with fibrocartilage and new blood vessels, "
            "(c) hard callus with spongy and bony callus forming, "
            "(d) remodelling into lamellar bone and normal anatomical shape.")
story.append(SP(8))

story += [
    H3("Primary vs Secondary Bone Healing"),
    P("<b>Secondary (indirect) healing</b> — the most common type, described above (with callus). "
      "Occurs in non-operative fracture management."),
    P("<b>Primary (direct) healing</b> — requires the broken ends to be held together "
      "tightly (e.g. with a plate and screws). Bone heals directly without forming a callus. "
      "This is done in open reduction and internal fixation (ORIF) surgery."),
    SP(8),
]

# ── 3.2 Nerve ────────────────────────────────────────────────────────────────
story += [
    H2("3.2  Nerve Healing"),
    P("Nerve healing is more complex. When a peripheral nerve is cut or crushed, different "
      "things happen at each end of the injury:"),
    SP(4),
]

nerve_flow = [
    flow_box("INJURY OCCURS", C_FLOW_BG2),
    flow_arrow(),
    flow_box("DISTAL STUMP (the end away from the brain): Wallerian Degeneration\n"
             "The nerve fibre breaks down → myelin debris is produced", C_FLOW_BG),
    flow_arrow(),
    flow_box("Schwann cells clean up the debris (macrophages help too)\n"
             "Schwann cells form 'Bands of Büngner' — tunnels to guide regrowth", HexColor("#2980B9")),
    flow_arrow(),
    flow_box("PROXIMAL STUMP (the end near the brain): Axonal Regeneration\n"
             "New nerve fibres grow out and are guided by neurotropism (chemical signals)\n"
             "Remyelination occurs → nerve function is restored", C_FLOW_BG3),
    SP(6),
    P("<i>Note: Growth factors, hormones, and the extracellular matrix guide the regenerating "
      "nerve. Injury to the perineurium (the nerve's outer sheath) can cause painful neuroma "
      "formation (a tangled, disorganised nerve ball).</i>"),
]
for item in nerve_flow:
    story.append(item)
story.append(SP(8))

story += embed_image("img03", width=10*cm,
    caption="Figure 3.4 — Nerve degeneration and regeneration: (a) Normal nerve, "
            "(b) Wallerian degeneration after injury, (c) Schwann cells proliferate and "
            "phagocytose myelin debris, (d) Axonal regeneration and remyelination along "
            "the Bands of Büngner back to the target organ.")
story.append(SP(8))

# ── 3.3 Tendon ───────────────────────────────────────────────────────────────
story += [
    H2("3.3  Tendon Healing"),
    P("Tendons (the tough cords that connect muscle to bone) repair via two mechanisms:"),
    Bul("<b>Intrinsic healing:</b> Blood flow and synovial fluid (joint lubricant) from "
        "inside the tendon itself nourish the healing process. This is the better type "
        "— it produces stronger, more flexible healing."),
    Bul("<b>Extrinsic healing:</b> Fibrous adhesions form between the tendon and the "
        "surrounding tendon sheath. This can restrict movement."),
    SP(4),
    P("Early movement after tendon repair promotes intrinsic healing and prevents "
      "adhesions. However, tendons must also be protected with a splint to prevent rupture."),
    SP(10),
]

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 4: ABNORMAL WOUND HEALING
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("4.  Abnormal Wound Healing"),
    P("Sometimes wounds fail to heal properly. Factors that interfere with healing can be "
      "divided into <b>local</b> (at the wound) and <b>systemic</b> (affecting the whole body)."),
    SP(6),
]

# Summary Box 3.1
factors_local = [
    Bul("Skin tension (too much pulling)"),
    Bul("Hypoxia and ischaemia (low oxygen / poor blood supply)"),
    Bul("Vascular insufficiency (blocked arteries or veins)"),
    Bul("Lymphoedema (swelling from blocked lymph vessels)"),
    Bul("Contamination and infection"),
    Bul("Presence of foreign bodies"),
    Bul("Radiotherapy (damages blood vessels and DNA)"),
]
factors_sys = [
    Bul("Advancing age"),
    Bul("Obesity"),
    Bul("Malnutrition"),
    Bul("Smoking (reduces oxygen delivery)"),
    Bul("Diseases: diabetes mellitus, connective tissue disease"),
    Bul("Immunocompromised states (e.g. HIV/AIDS)"),
    Bul("Medications: steroids, immunosuppressants, chemotherapy"),
]
story.append(box("Summary Box 3.1 — Factors Affecting Wound Healing",
    [H3("LOCAL Factors:")] + factors_local + [SP(4), H3("SYSTEMIC Factors:")] + factors_sys))
story.append(SP(10))

# ── 4.1 Hypertrophic and Keloid Scars ────────────────────────────────────────
story += [
    H2("4.1  Abnormal Scarring: Hypertrophic vs Keloid Scars"),
    P("When too much collagen is produced, you get abnormal scars. Collagen is arranged "
      "in a <b>disorganised</b> pattern (rather than parallel) in these scars."),
    SP(6),
]

scar_data = [
    [Paragraph("Feature", sty_tbl_hdr),
     Paragraph("Hypertrophic Scar", sty_tbl_hdr),
     Paragraph("Keloid Scar", sty_tbl_hdr)],
    [Paragraph("Boundaries", sty_tbl_cell),
     Paragraph("Stays within the original wound boundary", sty_tbl_cell),
     Paragraph("Extends BEYOND the wound boundary", sty_tbl_cell)],
    [Paragraph("Spontaneous regression", sty_tbl_cell),
     Paragraph("Often regresses on its own over time", sty_tbl_cell),
     Paragraph("Does NOT regress spontaneously", sty_tbl_cell)],
    [Paragraph("Common locations", sty_tbl_cell),
     Paragraph("High tension areas, crossing tension lines, deep burns", sty_tbl_cell),
     Paragraph("Earlobes, chest, upper arms — darker skin types more prone", sty_tbl_cell)],
    [Paragraph("Treatment", sty_tbl_cell),
     Paragraph("Pressure therapy, silicone, steroids, laser", sty_tbl_cell),
     Paragraph("Difficult — surgery + adjuvants needed, high recurrence", sty_tbl_cell)],
]
col_ws2 = [3.5*cm, 6.5*cm, 6.5*cm]
st2 = Table(scar_data, colWidths=col_ws2)
st2.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(st2)
story.append(SP(10))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 5: TYPES OF WOUND HEALING
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("5.  Types of Wound Healing"),
    SP(4),
]

healing_data = [
    [Paragraph("Type", sty_tbl_hdr),
     Paragraph("Also called", sty_tbl_hdr),
     Paragraph("How it works", sty_tbl_hdr),
     Paragraph("Result", sty_tbl_hdr)],
    [Paragraph("Primary", sty_tbl_cell),
     Paragraph("Healing by first intention", sty_tbl_cell),
     Paragraph("Wound edges are directly stitched together (apposed)", sty_tbl_cell),
     Paragraph("Minimal scar", sty_tbl_cell)],
    [Paragraph("Secondary", sty_tbl_cell),
     Paragraph("Healing by second intention", sty_tbl_cell),
     Paragraph("Wound left open; heals by granulation, contraction, and re-epithelialisation from edges inward", sty_tbl_cell),
     Paragraph("Larger scar, more inflammation", sty_tbl_cell)],
    [Paragraph("Tertiary (Delayed Primary)", sty_tbl_cell),
     Paragraph("Healing by third intention", sty_tbl_cell),
     Paragraph("Wound initially left open (e.g. to clean infection), then edges apposed once conditions are favourable", sty_tbl_cell),
     Paragraph("Intermediate scar", sty_tbl_cell)],
]
col_ws3 = [2.5*cm, 3.5*cm, 7*cm, 3.5*cm]
ht = Table(healing_data, colWidths=col_ws3)
ht.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(ht)
story.append(SP(10))

# ════════════════════════════════════════════════════════════════════════════
# SECTION 6: CLASSIFICATION OF WOUNDS
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("6.  Classification of Wounds"),
    P("There is no single universal system for classifying wounds. Multiple systems exist, "
      "each looking at different aspects. Key classification systems:"),
    SP(6),
]

story.append(box("Summary Box 3.3 — Systems of Wound Classification",
    [
        H3("By CAUSE (Aetiology):"),
        Bul("Clean surgical / Shearing or degloving / Crush / Blast"),
        Bul("Burn (thermal, electrical, chemical, radiation, mechanical)"),
        Bul("Cold injury / Avulsion or traction / Low or high energy / Bite"),
        SP(4),
        H3("By DEPTH:"),
        Bul("Epidermal → Dermal (superficial or deep) → Full thickness"),
        SP(4),
        H3("By CONTAMINATION:"),
        Bul("Clean → Clean-contaminated → Contaminated → Dirty"),
        Bul("Implant or non-implant"),
        SP(4),
        H3("By COMPLEXITY:"),
        Bul("Simple → Complex → Significant soft-tissue loss"),
        Bul("Open fracture or joint / Visceral involvement"),
        Bul("Complicated: Infection, Necrosis, Haematoma, Gas gangrene, Compartment syndrome"),
        SP(4),
        H3("By CHRONICITY:"),
        Bul("Chronic: Vascular ulcers (venous or arterial), Pressure ulcers, Diabetic ulcers"),
    ]
))
story.append(SP(8))

# US CDC Table 3.1
story += [
    H2("US CDC Surgical Wound Classification"),
    P("The most widely used system, introduced in 1964, classifies surgical wounds into "
      "four classes based on bacterial contamination risk:"),
    SP(4),
]
cdc_data = [
    [Paragraph("Class", sty_tbl_hdr),
     Paragraph("Name", sty_tbl_hdr),
     Paragraph("Description", sty_tbl_hdr)],
    [Paragraph("Class I", sty_tbl_cell),
     Paragraph("Clean", sty_tbl_cell),
     Paragraph("No inflammation. Respiratory/GI/urinary tracts not entered. Primarily closed.", sty_tbl_cell)],
    [Paragraph("Class II", sty_tbl_cell),
     Paragraph("Clean-contaminated", sty_tbl_cell),
     Paragraph("Respiratory/GI/urinary tracts entered under controlled conditions. No infection.", sty_tbl_cell)],
    [Paragraph("Class III", sty_tbl_cell),
     Paragraph("Contaminated", sty_tbl_cell),
     Paragraph("Open fresh wounds. Gross spillage from GI tract. Operations with acute non-purulent inflammation.", sty_tbl_cell)],
    [Paragraph("Class IV", sty_tbl_cell),
     Paragraph("Dirty", sty_tbl_cell),
     Paragraph("Old traumatic wounds. Retained devitalised tissue. Existing clinical infection or perforated viscera.", sty_tbl_cell)],
]
col_ws4 = [2*cm, 3.5*cm, 11*cm]
cdct = Table(cdc_data, colWidths=col_ws4)
cdct.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(cdct)
story.append(SP(10))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 7: WOUND MANAGEMENT
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("7.  Wound Management"),
    P("Good wound management is guided by the timing and mechanism of injury, plus factors "
      "affecting healing. Patient expectations and post-op compliance also matter."),
    SP(6),
]

story += embed_image("img04", width=14*cm,
    caption="Figure 3.5 — Multiple keloid scars (clinical photograph).")
story.append(SP(6))

# Table 3.2 Principles
story += [
    H2("7.1  Principles of Wound Management (Table 3.2)"),
    SP(4),
]
mgmt_data = [
    [Paragraph("Phase", sty_tbl_hdr), Paragraph("Actions", sty_tbl_hdr)],
    [Paragraph("Preparation", sty_tbl_cell),
     Paragraph("• Antibiotic prophylaxis if needed\n• Tetanus prophylaxis\n• Adequate analgesia/anaesthesia\n• Wound irrigation (with warm saline)", sty_tbl_cell)],
    [Paragraph("Wound", sty_tbl_cell),
     Paragraph("• Early debridement (remove dead tissue) and irrigation\n• Exploration (check what structures are involved)\n• Repair structures (tendons, nerves, vessels)\n• Haemostasis (stop bleeding)", sty_tbl_cell)],
    [Paragraph("Closure", sty_tbl_cell),
     Paragraph("• Skin closure without tension\n• Consider reconstruction options (see Section 7.3)\n• Suture choice\n• Consider drains\n• Optimal dressings", sty_tbl_cell)],
    [Paragraph("Follow-up", sty_tbl_cell),
     Paragraph("• Remove sutures/splints at appropriate time\n• Physiotherapy\n• Monitor for complications\n• Scar management", sty_tbl_cell)],
]
col_ws5 = [3.5*cm, 13*cm]
mt = Table(mgmt_data, colWidths=col_ws5)
mt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(mt)
story.append(SP(10))

# ── 7.2 Tetanus ──────────────────────────────────────────────────────────────
story += [
    H2("7.2  Tetanus Prophylaxis"),
    P("Tetanus is caused by the bacterium <i>Clostridium tetani</i> producing a toxin "
      "that causes severe muscle spasms. It is preventable with vaccination."),
    SP(4),
    P("<b>Tetanus-prone wounds</b> are those that carry a higher risk:"),
    Bul("Puncture wounds in contaminated environments"),
    Bul("Bites, compound fractures, wounds with foreign bodies"),
    Bul("Wounds with burns or systemic sepsis"),
    SP(4),
    P("<b>High-risk tetanus-prone wounds</b> additionally have:"),
    Bul("Heavy contamination (soil or manure)"),
    Bul("Surgery requiring >6-hour delay"),
    Bul("Extensive devitalised tissue"),
    SP(4),
]

story += embed_image("img04", width=14*cm,
    caption="Figure 3.6 — Post-exposure management algorithm for tetanus-prone wounds. "
            "Management depends on immunisation status and wound type. "
            "Unvaccinated patients may need both a reinforcing vaccine dose AND human tetanus "
            "immunoglobulin (HNIG) injected at a different site.")
story.append(SP(8))

# ── 7.3 Debridement ──────────────────────────────────────────────────────────
story += [
    H2("7.3  Debridement — Removing Dead Tissue"),
    P("Debridement means removing dead, infected, or contaminated tissue from a wound "
      "so healthy tissue can take over. The endpoint is healthy bleeding tissue at the "
      "wound edges."),
    SP(4),
]
deb_data = [
    [Paragraph("Type", sty_tbl_hdr), Paragraph("Method", sty_tbl_hdr)],
    [Paragraph("Surgical", sty_tbl_cell),
     Paragraph("Cut away dead tissue using scalpel, curette, scissors or rongeur until healthy bleeding is seen", sty_tbl_cell)],
    [Paragraph("Mechanical", sty_tbl_cell),
     Paragraph("Irrigation, wet-to-dry dressings, hydrotherapy — removes both viable and non-viable tissue (non-selective)", sty_tbl_cell)],
    [Paragraph("Autolytic", sty_tbl_cell),
     Paragraph("Use moisture-retaining dressings (hydrocolloids, transparent films) — the body's own enzymes liquefy dead tissue", sty_tbl_cell)],
    [Paragraph("Enzymatic", sty_tbl_cell),
     Paragraph("Apply chemical enzymes (collagenase, papain-urea) to dissolve dead tissue", sty_tbl_cell)],
    [Paragraph("Biological", sty_tbl_cell),
     Paragraph("Medical-grade maggots (Lucilia sericata larvae) eat dead tissue and release antimicrobial substances that promote healing", sty_tbl_cell)],
]
col_ws6 = [3.5*cm, 13*cm]
dt = Table(deb_data, colWidths=col_ws6)
dt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(dt)
story.append(SP(8))

story.append(PageBreak())

# ── 7.4 Wound Closure & Reconstruction Ladder ────────────────────────────────
story += [
    H2("7.4  Wound Closure and the Reconstructive Ladder"),
    P("Wound closure should always be without tension. The 'Reconstructive Ladder' provides "
      "a framework, starting with the simplest option and going up in complexity:"),
    SP(6),
]

ladder_flow = [
    ("1. Primary Closure",     "Direct suturing of wound edges", C_FLOW_BG3),
    ("2. Secondary Closure",   "Leave wound open to heal on its own (granulation)", HexColor("#27AE60")),
    ("3. Tertiary/Delayed Primary", "Close later when conditions improve", HexColor("#1ABC9C")),
    ("4. NPWT",                "Negative-Pressure Wound Therapy (VAC dressing)", C_FLOW_BG),
    ("5. Split-Thickness Skin Graft", "Thin layer of skin taken from donor site", HexColor("#2980B9")),
    ("6. Full-Thickness Skin Graft",  "Thicker skin graft (better cosmetics)", HexColor("#8E44AD")),
    ("7. Dermal Matrices",     "Synthetic scaffolds to support wound healing", HexColor("#7D3C98")),
    ("8. Local / Regional Flap", "Nearby tissue rotated or advanced to cover defect", C_FLOW_BG2),
    ("9. Tissue Expansion",    "Slowly stretch nearby skin using an inflatable balloon implant", HexColor("#D35400")),
    ("10. Free Flap",          "Tissue completely detached from donor site and microsurgically joined to recipient site", HexColor("#C0392B")),
]
for step, desc, col in ladder_flow:
    story.append(
        Table(
            [[Paragraph(f"<b>{step}</b>", sty_flow),
              Paragraph(desc, S("dl", fontName="Helvetica", fontSize=9.5, textColor=C_DARK,
                  alignment=TA_LEFT, leading=13))]],
            colWidths=[5.5*cm, 11*cm]
        )
    )
    story[-1].setStyle(TableStyle([
        ('BACKGROUND', (0,0), (0,0), col),
        ('BACKGROUND', (1,0), (1,0), C_BOX_BG),
        ('LEFTPADDING', (0,0), (-1,-1), 8),
        ('RIGHTPADDING', (0,0), (-1,-1), 8),
        ('TOPPADDING', (0,0), (-1,-1), 6),
        ('BOTTOMPADDING', (0,0), (-1,-1), 6),
        ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
        ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ]))
    story.append(SP(2))
story.append(SP(6))

# Skin grafts & flaps
story += [
    H3("Skin Grafts"),
    Bul("<b>Split-thickness skin graft (STSG):</b> Epidermis + a thin slice of dermis. "
        "Taken from donor site using a dermatome. Used for large wounds."),
    Bul("<b>Full-thickness skin graft (FTSG):</b> Epidermis + all of dermis. Better colour "
        "match, less contraction. Used for smaller defects on face/hands."),
    P("Grafts have no blood supply of their own — they depend entirely on the recipient "
      "wound bed for survival. The bed must be well-vascularised (good blood flow)."),
    SP(6),
    H3("Flaps"),
    Bul("<b>Pedicled flap:</b> Tissue moved to a nearby area while still attached to its "
        "original blood supply."),
    Bul("<b>Free flap:</b> Tissue completely detached and blood vessels reconnected "
        "microsurgically at the new site. Requires a microscope."),
    SP(8),
]

story += embed_image("img05", width=11*cm,
    caption="Figure 3.7 — Meshed split-thickness skin graft. Meshing allows the graft to "
            "cover a larger area and lets fluid drain through.")
story.append(SP(6))

story += embed_image("img05", width=14*cm,
    caption="Figure 3.8 — (a,b) Left mastectomy; (c,d) Delayed breast reconstruction "
            "using a deep inferior epigastric artery perforator (DIEP) free flap and "
            "nipple reconstruction.")
story.append(SP(8))

story.append(PageBreak())

# ── 7.5 NPWT ─────────────────────────────────────────────────────────────────
story += [
    H2("7.5  Negative-Pressure Wound Therapy (NPWT)"),
    P("NPWT (also called a VAC — Vacuum-Assisted Closure — dressing) uses a foam dressing "
      "sealed with an airtight film and connected to a suction pump. It creates negative "
      "pressure (a gentle vacuum) at the wound."),
    SP(4),
    P("How NPWT helps:"),
    Bul("Draws wound edges together"),
    Bul("Removes excess fluid (exudate) from the wound"),
    Bul("Reduces swelling (oedema)"),
    Bul("Promotes new tissue (granulation tissue) formation"),
    Bul("Reduces the risk of infection"),
    SP(4),
    P("<b>NPWT is NOT used for:</b> exposed vessels or organs, malignancy, untreated "
      "osteomyelitis, necrotic tissue, or unexplored fistulae."),
    SP(4),
    P("NPWT is a useful bridge to definitive wound closure — it prepares the wound bed "
      "but does not replace final closure."),
    SP(8),
]

story += embed_image("img05", width=11*cm,
    caption="Figure 3.9 — Negative-pressure wound therapy (VAC dressing) applied to a lower limb wound.")
story.append(SP(10))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 8: ACUTE WOUNDS
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("8.  Acute Wounds"),
]

# ── 8.1 Bites ────────────────────────────────────────────────────────────────
story += [
    H2("8.1  Bites"),
    P("Most bites are either puncture wounds or avulsions (tearing away of tissue). "
      "Any wound over the knuckle following a punch to the mouth should be treated as a "
      "human bite (high infection risk)."),
    Bul("High-pressure injection injuries to the hand may look minor but can track "
        "chemical/grease deeply into the forearm — always explore and debride urgently."),
    SP(8),
]

# ── 8.2 Degloving ────────────────────────────────────────────────────────────
story += [
    H2("8.2  Degloving Injuries"),
    P("Degloving = the skin and subcutaneous fat are <b>stripped away</b> from the underlying "
      "fascia, muscle, or bone — like peeling off a glove."),
    Bul("<b>Open degloving:</b> Skin is visibly lost (e.g. finger avulsion)."),
    Bul("<b>Closed degloving (Morel-Lavallée lesion):</b> Skin appears intact but the "
      "subcutaneous tissue has been sheared away underneath, creating a fluid-filled space "
      "between the skin and deep fascia. Often seen after car accidents, over the greater "
      "trochanter (hip area)."),
    SP(4),
]

story.append(box("Summary Box 3.5 — Classification of Degloving Injuries",
    [
        Bul("1 — Limited degloving with abrasion or avulsion"),
        Bul("2 — Non-circumferential degloving"),
        Bul("3 — Circumferential single plane degloving"),
        Bul("4 — Circumferential multiplanar degloving (may require amputation)"),
    ]))
story.append(SP(8))

story += embed_image("img06", width=10*cm,
    caption="Figure 3.10 — Degloving injury of the right little and ring fingers.")
story.append(SP(4))
story += embed_image("img06", width=10*cm,
    caption="Figure 3.11 — Degloving buttock injury.")
story.append(SP(4))
story += embed_image("img06", width=9*cm,
    caption="Figure 3.12 — Morel-Lavallée lesion mechanism: shearing forces cause the subcutaneous "
            "tissue to separate from the deep fascia, creating a haemolymphatic collection.")
story.append(SP(8))

# ── 8.3 Compartment Syndrome ─────────────────────────────────────────────────
story += [
    H2("8.3  Acute Compartment Syndrome"),
    P("Compartment syndrome occurs when pressure builds up inside a tight fascial "
      "compartment (the fibrous sleeve around muscles), cutting off blood supply. "
      "It is a <b>surgical emergency</b>."),
    SP(4),
]

cs_flow = [
    flow_box("CAUSE: Lower limb fracture, soft-tissue trauma, burns, crush injury", C_FLOW_BG2),
    flow_arrow(),
    flow_box("↑ Interstitial pressure in closed compartment", C_FLOW_BG),
    flow_arrow(),
    flow_box("Microvascular compromise → Muscle ischaemia", HexColor("#E74C3C")),
    flow_arrow(),
    flow_box("SYMPTOMS:\n• Pain OUT OF PROPORTION to injury\n• Pain on PASSIVE STRETCH of affected muscles\n• Paraesthesia (pins and needles)\n• Absent pulses (late sign)", C_FLOW_BG),
    flow_arrow(),
    flow_box("DIAGNOSIS: Clinical + measure intracompartmental pressure (ICP)\n(Pressure ≥30 mmHg between diastolic and ICP = threshold for surgery)", HexColor("#7F8C8D")),
    flow_arrow(),
    flow_box("TREATMENT: Emergency FASCIOTOMY\n(Long incisions through skin + deep fascia to release pressure)", C_FLOW_BG3),
    flow_arrow(),
    flow_box("IF DELAYED: Rhabdomyolysis, infection, amputation, death", HexColor("#C0392B")),
]
for item in cs_flow:
    story.append(item)
story.append(SP(8))

story += embed_image("img07", width=8*cm,
    caption="Figure 3.13 — Fasciotomy of the leg. Long incisions through the skin and deep fascia "
            "release the pressure. The lower limb requires two incisions to decompress all four "
            "compartments.")
story.append(SP(8))

# ── 8.4 Necrotising Fasciitis ─────────────────────────────────────────────────
story += [
    H2("8.4  Necrotising Fasciitis"),
    P("Necrotising fasciitis is a rapidly spreading, life-threatening infection of the skin, "
      "subcutaneous tissue, and fascia. Also called 'flesh-eating disease'."),
    Bul("Most common organism: <i>Streptococcus pyogenes</i> (Group A strep)"),
    Bul("Also: <i>Staphylococcus aureus, E. coli, Pseudomonas, Clostridium, Bacteroides</i>"),
    Bul("Mortality: up to 26% at 30 days, up to 40% at 1 year"),
    SP(4),
]

story.append(box("Summary Box 3.6 — Signs and Symptoms of Necrotising Fasciitis",
    [
        H3("LOCAL signs:"),
        Bul("Unusual/disproportionate pain"),
        Bul("Erythema (redness), oedema (swelling), warmth"),
        Bul("Crepitus (crackling sensation under skin = gas-producing bacteria)"),
        Bul("Blisters and bullae"),
        Bul("Greyish 'dishwater pus' drainage"),
        Bul("Fixed staining, necrosis, gangrene"),
        SP(4),
        H3("SYSTEMIC signs:"),
        Bul("Fever, fast heart rate (tachycardia), fast breathing (tachypnoea)"),
        Bul("Shock"),
        Bul("Coagulopathy (clotting problems)"),
        Bul("Multi-organ failure"),
    ]
))
story.append(SP(6))

nf_flow = [
    flow_box("DIAGNOSIS: Clinical — Do NOT delay treatment waiting for results!", C_FLOW_BG2),
    flow_arrow(),
    flow_box("IV Antibiotics immediately (broad spectrum)", C_FLOW_BG),
    flow_arrow(),
    flow_box("Emergency RADICAL SURGICAL DEBRIDEMENT\n(Remove ALL infected/dead tissue)", HexColor("#E74C3C")),
    flow_arrow(),
    flow_box("'Second look' surgery in 24–48 hours\n(Multiple debridements often needed)", HexColor("#C0392B")),
    flow_arrow(),
    flow_box("Wound reconstruction once infection controlled", C_FLOW_BG3),
]
for item in nf_flow:
    story.append(item)
story.append(SP(8))

story += embed_image("img07", width=10*cm,
    caption="Figure 3.14 — Necrotising fasciitis of the anterior abdominal wall. "
            "Note the extensive tissue destruction and discolouration.")
story.append(SP(10))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 9: CHRONIC WOUNDS
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("9.  Chronic Wounds"),
    P("Chronic wounds are wounds that <b>fail to progress</b> through the normal healing "
      "stages in a timely manner. They are stuck, usually in a prolonged inflammatory phase "
      "with persistent infection."),
    P("The most common chronic wounds in developed countries are <b>leg ulcers</b> and "
      "<b>pressure ulcers</b>. Treatment involves debridement, infection control, and "
      "appropriate dressings."),
    SP(8),
]

# ── 9.1 Leg Ulcers ────────────────────────────────────────────────────────────
story += [
    H2("9.1  Leg Ulcers"),
    P("A leg ulcer is a break in the skin on the lower leg that fails to heal. Causes:"),
]

story.append(box("Summary Box 3.7 — Causes of Leg Ulcers",
    [
        Bul("Vascular: venous, arterial, or mixed"),
        Bul("Trauma: bites, self-inflicted, burns"),
        Bul("Infection: bacterial, fungal, mycobacterial, syphilis"),
        Bul("Metabolic disorders: diabetes mellitus, gout, calciphylaxis"),
        Bul("Autoimmune: vasculitis, systemic sclerosis, rheumatoid arthritis"),
        Bul("Neoplastic: squamous cell carcinoma (Marjolin's ulcer), basal cell carcinoma"),
    ]
))
story.append(SP(6))

story += [
    P("A chronic ulcer that does not respond to dressings and treatment should be biopsied "
      "to rule out <b>Marjolin's ulcer</b> (a squamous cell carcinoma that develops in a "
      "chronic scar — described by Jean-Nicholas Marjolin in 1828)."),
    P("Treatment addresses the underlying cause. Arterial and venous circulation should be "
      "assessed. Surgery is only indicated if non-operative treatment has failed."),
    SP(8),
]

# ── 9.2 Pressure Ulcers ──────────────────────────────────────────────────────
story += [
    H2("9.2  Pressure Ulcers (Pressure Injuries)"),
    P("Pressure ulcers form when sustained pressure over a bony prominence cuts off blood "
      "supply to overlying tissue. They are largely <b>preventable</b>."),
    SP(4),
    P("<b>Common sites:</b> Sacrum, ischium, greater trochanter, heel, malleolus, occiput."),
    SP(4),
    P("<b>Risk factors:</b> Severely ill patients, impaired mobility, loss of sensation."),
    SP(4),
    P("<b>Prevention:</b> Risk scoring (Braden, Waterlow, or Norton scales), skin assessment, "
      "repositioning every 2–4 hours, pressure-redistributing mattresses, nutrition support."),
    SP(6),
]

staging_data = [
    [Paragraph("Stage", sty_tbl_hdr), Paragraph("Description", sty_tbl_hdr)],
    [Paragraph("1", sty_tbl_cell), Paragraph("Non-blanchable redness of intact skin", sty_tbl_cell)],
    [Paragraph("2", sty_tbl_cell), Paragraph("Partial-thickness skin loss with exposed dermis", sty_tbl_cell)],
    [Paragraph("3", sty_tbl_cell), Paragraph("Full-thickness skin loss", sty_tbl_cell)],
    [Paragraph("4", sty_tbl_cell), Paragraph("Full-thickness skin AND tissue loss (down to bone/muscle/tendon)", sty_tbl_cell)],
    [Paragraph("Unstageable", sty_tbl_cell), Paragraph("Obscured full-thickness loss (covered by slough/eschar)", sty_tbl_cell)],
    [Paragraph("Deep tissue injury", sty_tbl_cell), Paragraph("Persistent non-blanchable, deep red/maroon/purple discolouration", sty_tbl_cell)],
]
col_ws7 = [3.5*cm, 13*cm]
stgt = Table(staging_data, colWidths=col_ws7)
stgt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('BACKGROUND', (0,6), (-1,6), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(stgt)
story.append(SP(4))
story.append(Cap("Table 3.5 — US National Pressure Injury Advisory Panel staging of pressure injuries"))
story.append(SP(8))

story += embed_image("img07", width=10*cm,
    caption="Figure 3.15 — Pressure ulcer (pressure injury) showing full-thickness tissue loss.")
story.append(SP(10))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 10: SCAR MANAGEMENT
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("10.  Scar Management"),
    H2("10.1  Principles of Scar Formation"),
    P("During the remodelling phase, the wound area becomes a scar. Understanding how a "
      "scar matures helps guide management:"),
    Bul("Initially: pink, hard, raised, itchy"),
    Bul("Over months: fibroblasts and blood vessels reduce → scar becomes paler, softer, flatter"),
    Bul("Most changes happen in the first <b>3 months</b>"),
    Bul("A scar continues to mature for <b>1–2 years</b> (sometimes longer)"),
    Bul("Tensile strength reaches ~80% of normal skin — never 100%"),
    SP(6),
    H2("10.2  Preventing Bad Scars"),
    P("<b>Prevention is better than treatment.</b> Key surgical principles:"),
    Bul("Place incisions along <b>relaxed skin tension lines</b> (natural skin creases)"),
    Bul("Avoid straight-line incisions across flexion creases"),
    Bul("Close wounds without tension"),
    Bul("Early debridement to prevent dirt-ingrained (tattooed) scars"),
    Bul("Subcuticular (buried) sutures to avoid suture marks"),
    Bul("Remove sutures at the right time (face 5 days; lower limb 10–14 days)"),
    SP(4),
    P("After closure: tension relief taping, hydration, ultraviolet protection, silicone "
      "sheeting or gel (first-line for hypertrophic and keloid scars)."),
    SP(8),
]

story += embed_image("img08", width=9*cm,
    caption="Figure 3.16 — Dirt-ingrained (tattooed) scar caused by inadequate initial wound cleaning.")
story.append(SP(8))

# ── 10.3 Hypertrophic scars ───────────────────────────────────────────────────
story += [
    H2("10.3  Management of Hypertrophic Scars (Algorithm)"),
    P("The management algorithm depends on the type of hypertrophic scar:"),
    Bul("<b>Immature hypertrophic</b> (red, slightly raised): Start silicone gel/sheeting + "
        "prevention measures. If it persists >1 month, treat as linear hypertrophic."),
    Bul("<b>Linear hypertrophic</b> (red/raised, itchy): Intralesional corticosteroid injections "
        "(monthly), then PDL or fractional laser, then pressure therapy, then surgical excision "
        "if needed."),
    Bul("<b>Widespread burn hypertrophic</b> (red/raised): Speciality burn unit referral + "
        "silicone sheeting + pressure garments + onion extract cream."),
    SP(6),
]

story += embed_image("img08", width=14*cm,
    caption="Figure 3.17 — Management algorithm for hypertrophic scars. Light grey = initial strategies; "
            "dark grey = secondary options. PDL = pulsed-dye laser. 5-FU = 5-fluorouracil.")
story.append(SP(8))

# ── 10.4 Keloid scars ────────────────────────────────────────────────────────
story += [
    H2("10.4  Management of Keloid Scars (Algorithm)"),
    Bul("<b>Minor keloid</b> (red/raised): Silicone gel/sheeting + intralesional corticosteroids. "
        "Then fractional or pulsed-dye laser."),
    Bul("<b>Major, high-risk keloid</b> (dark/raised): Intralesional corticosteroids first, then "
        "5-FU + intralesional corticosteroids, then laser. Counsel patient on recurrence risk. "
        "Surgical excision with adjuvants (silicone, radiotherapy, bleomycin) as last resort."),
    SP(6),
]

story += embed_image("img09", width=13*cm,
    caption="Figure 3.18 — Management algorithm for keloids. Light grey = initial strategies; "
            "dark grey = secondary options. Note: ablative fractional lasers are preferred for minor keloids. "
            "Cryotherapy can be used alongside intralesional corticosteroids.")
story.append(SP(8))

# ── 10.5 Scar Contractures ───────────────────────────────────────────────────
story += [
    H2("10.5  Scar Contractures"),
    P("A contracture is when a scar <b>tightens and shortens</b> over time, restricting "
      "movement of the underlying joint or structure. This can cause significant functional "
      "disability."),
    Bul("Can result from differential growth rate between the scar and surrounding tissues"),
    Bul("Surgical release involves replacing the tight scar with healthy, pliable tissue"),
    Bul("Common procedures: <b>Z-plasty</b> (and variants Y-V, V-Y, W-plasty) — rearrange "
        "local tissue to lengthen the scar"),
    Bul("Free flaps may be needed for severe contractures"),
    SP(6),
]

story += embed_image("img01", width=9*cm,
    caption="Figure 3.19 — Midline neck contracture from a chainsaw injury.")
story.append(SP(4))
story += embed_image("img01", width=10*cm,
    caption="Figure 3.20 — Multiple Z-plasty release of a finger contracture. "
            "The Z-shaped cuts allow tissue to be rearranged to lengthen the scar.")
story.append(SP(10))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# QUICK REFERENCE SUMMARY
# ════════════════════════════════════════════════════════════════════════════
story += [
    H1("Quick Reference Summary"),
    SP(4),
]

summary_data = [
    [Paragraph("Topic", sty_tbl_hdr), Paragraph("Key Point", sty_tbl_hdr)],
    [Paragraph("Wound healing phases", sty_tbl_cell),
     Paragraph("Haemostasis → Inflammation (days 1–3) → Proliferation (day 3–4 wks) → Remodelling (2 wks–1+ yr)", sty_tbl_cell)],
    [Paragraph("Max tensile strength", sty_tbl_cell),
     Paragraph("~80% of normal skin, reached at 12 weeks post-injury", sty_tbl_cell)],
    [Paragraph("Bone healing", sty_tbl_cell),
     Paragraph("Haematoma → Soft callus (fibrocartilage) → Hard callus (woven bone) → Remodelling (lamellar bone)", sty_tbl_cell)],
    [Paragraph("Nerve healing", sty_tbl_cell),
     Paragraph("Wallerian degeneration distally → Schwann cells form Bands of Büngner → Axonal regeneration guided by neurotropism", sty_tbl_cell)],
    [Paragraph("Hypertrophic vs keloid", sty_tbl_cell),
     Paragraph("Hypertrophic: within wound boundary, may regress. Keloid: beyond boundary, does not regress, genetic predisposition", sty_tbl_cell)],
    [Paragraph("Wound classification", sty_tbl_cell),
     Paragraph("CDC: Class I (clean) → II (clean-contaminated) → III (contaminated) → IV (dirty)", sty_tbl_cell)],
    [Paragraph("Compartment syndrome", sty_tbl_cell),
     Paragraph("Surgical emergency → fasciotomy. Signs: disproportionate pain, pain on passive stretch, paraesthesia", sty_tbl_cell)],
    [Paragraph("Necrotising fasciitis", sty_tbl_cell),
     Paragraph("Surgical emergency → radical debridement + IV antibiotics. Signs: dishwater pus, crepitus, systemic sepsis", sty_tbl_cell)],
    [Paragraph("Pressure ulcer prevention", sty_tbl_cell),
     Paragraph("Risk scoring (Braden/Waterlow/Norton), reposition q2–4h, pressure-redistribution mattress, nutrition optimisation", sty_tbl_cell)],
    [Paragraph("Scar management", sty_tbl_cell),
     Paragraph("First line: silicone sheeting/gel, pressure therapy. Second line: intralesional corticosteroids, laser. Last resort: surgery", sty_tbl_cell)],
]
col_ws8 = [4.5*cm, 12*cm]
sumt = Table(summary_data, colWidths=col_ws8)
sumt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_TBL_HEAD),
    ('TEXTCOLOR', (0,0), (-1,0), white),
    ('BACKGROUND', (0,2), (-1,2), C_TBL_ALT),
    ('BACKGROUND', (0,4), (-1,4), C_TBL_ALT),
    ('BACKGROUND', (0,6), (-1,6), C_TBL_ALT),
    ('BACKGROUND', (0,8), (-1,8), C_TBL_ALT),
    ('BACKGROUND', (0,10), (-1,10), C_TBL_ALT),
    ('GRID', (0,0), (-1,-1), 0.5, HexColor("#CCCCCC")),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
]))
story.append(sumt)
story.append(SP(10))
story.append(HR())
story.append(SP(4))
story.append(Paragraph("End of Chapter 3 — Wound Healing and Tissue Repair",
    S("end", fontName="Helvetica-Oblique", fontSize=10, textColor=HexColor("#888888"),
      alignment=TA_CENTER)))

# ── build PDF ─────────────────────────────────────────────────────────────────
def footer(canvas, doc):
    canvas.saveState()
    canvas.setFont("Helvetica", 8)
    canvas.setFillColor(HexColor("#888888"))
    canvas.drawString(L_MARGIN, 1.2*cm, "Chapter 3 — Wound Healing and Tissue Repair")
    canvas.drawRightString(PAGE_W - R_MARGIN, 1.2*cm, f"Page {doc.page}")
    canvas.restoreState()

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    leftMargin=L_MARGIN,
    rightMargin=R_MARGIN,
    topMargin=T_MARGIN,
    bottomMargin=B_MARGIN + 0.8*cm,
)
doc.build(story, onFirstPage=footer, onLaterPages=footer)
print(f"\nPDF saved to: {OUTPUT}")

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/wound-healing-pdf/build_pdf.py'

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/wound-healing-pdf/build_pdf.py'

#!/usr/bin/env python3
"""
Enhanced PDF: Chapter 3 — Wound Healing and Tissue Repair
Structure: Key Terms + Process Flowchart + Quick Summary per topic
"""

from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import ParagraphStyle as PS
from reportlab.lib.units import cm
from reportlab.lib.colors import HexColor
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, PageBreak, Image as RLImage
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from PIL import Image as PILImage
import os

PAGE_W, PAGE_H = A4
L_M = R_M = 1.8*cm
T_M = B_M = 1.8*cm

C_HEAD = HexColor("#C0765A")     # salmon/brown
C_SUBH = HexColor("#2C3E50")     # dark
C_BOX  = HexColor("#FFF5F0")     # light salmon bg
C_FLOW = HexColor("#3B5998")     # blue
C_FLOW2= HexColor("#C0765A")     # salmon
C_OK   = HexColor("#27AE60")     # green
C_WARN = HexColor("#E74C3C")     # red

OUT = "/home/daytona/workspace/wound-v2/Chapter_3_Wound_Healing.pdf"
IMG_DIR = "/home/daytona/workspace/wound-v2/imgs"

def S(name, **kw):
    return PS(name, **kw)

# Styles
sty_title = S("title", fontName="Helvetica-Bold", fontSize=24, textColor=C_HEAD, spaceAfter=8, leading=32)
sty_h1 = S("h1", fontName="Helvetica-Bold", fontSize=16, textColor=C_HEAD, spaceBefore=14, spaceAfter=6, leading=20)
sty_h2 = S("h2", fontName="Helvetica-Bold", fontSize=12, textColor=C_SUBH, spaceBefore=10, spaceAfter=4, leading=16)
sty_h3 = S("h3", fontName="Helvetica-Bold", fontSize=11, textColor=C_HEAD, spaceBefore=8, spaceAfter=3)
sty_body = S("body", fontName="Helvetica", fontSize=9.5, textColor=C_SUBH, spaceAfter=5, leading=14, alignment=TA_JUSTIFY)
sty_bullet = S("bullet", fontName="Helvetica", fontSize=9, textColor=C_SUBH, leftIndent=12, firstLineIndent=-8, spaceAfter=3, leading=13)
sty_box_title = S("box_t", fontName="Helvetica-Bold", fontSize=10, textColor=C_HEAD, spaceAfter=3)
sty_box = S("box", fontName="Helvetica", fontSize=9, textColor=C_SUBH, leftIndent=8, spaceAfter=2, leading=12)
sty_flow = S("flow", fontName="Helvetica-Bold", fontSize=8.5, textColor="white", alignment=TA_CENTER, leading=12)
sty_cap = S("cap", fontName="Helvetica-Oblique", fontSize=8.5, textColor="#666666", spaceAfter=6, alignment=TA_CENTER)

def H1(t): return Paragraph(t, sty_h1)
def H2(t): return Paragraph(t, sty_h2)
def H3(t): return Paragraph(t, sty_h3)
def P(t): return Paragraph(t, sty_body)
def B(t): return Paragraph(f"• {t}", sty_bullet)
def SP(n=6): return Spacer(1, n*mm)
def Cap(t): return Paragraph(t, sty_cap)

def box(title, items, bg=C_BOX):
    """Summary box with title and bullet items"""
    content = [Paragraph(title, sty_box_title)] + items
    tbl = Table([[content]], colWidths=[PAGE_W - L_M - R_M - 0.3*cm])
    tbl.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), bg),
        ('BOX', (0,0), (-1,-1), 1, C_HEAD),
        ('LEFTPADDING', (0,0), (-1,-1), 10),
        ('RIGHTPADDING', (0,0), (-1,-1), 10),
        ('TOPPADDING', (0,0), (-1,-1), 8),
        ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ]))
    return tbl

def flow_step(text, color=C_FLOW):
    """Single flowchart step box"""
    inner = Paragraph(text, sty_flow)
    tbl = Table([[inner]], colWidths=[PAGE_W - L_M - R_M - 0.3*cm])
    tbl.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), color),
        ('LEFTPADDING', (0,0), (-1,-1), 12),
        ('RIGHTPADDING', (0,0), (-1,-1), 12),
        ('TOPPADDING', (0,0), (-1,-1), 8),
        ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ]))
    return tbl

def arrow(): return Paragraph("↓", S("arr", fontName="Helvetica", fontSize=12, textColor=C_SUBH, alignment=TA_CENTER, spaceAfter=2))

def embed_img(key, w=14*cm, cap=None):
    """Embed an image with optional caption"""
    path = f"{IMG_DIR}/{key}.jpg"
    if not os.path.exists(path): return [P(f"[Image {key} not found]")]
    
    pil = PILImage.open(path)
    orig_w, orig_h = pil.size
    h = w * orig_h / orig_w
    max_h = 17*cm
    if h > max_h: h, w = max_h, max_h * orig_w / orig_h
    
    img = RLImage(path, width=w, height=h)
    tbl = Table([[img]], colWidths=[PAGE_W - L_M - R_M])
    tbl.setStyle(TableStyle([('ALIGN', (0,0), (-1,-1), 'CENTER')]))
    
    items = [tbl]
    if cap: items.append(Cap(cap))
    return items

story = []

# ════════════════════════════════════════════════════════════════════════════
# COVER
# ════════════════════════════════════════════════════════════════════════════
story += [SP(30), Paragraph("CHAPTER 3", S("ch", fontName="Helvetica-Bold", fontSize=13, textColor=C_HEAD, alignment=TA_CENTER)),
    Paragraph("Wound Healing and Tissue Repair", S("ctitle", fontName="Helvetica-Bold", fontSize=28, textColor=C_SUBH, alignment=TA_CENTER, spaceAfter=20, leading=36)),
    SP(10), Paragraph("Simplified Guide with Flowcharts and Key Terms", S("sub", fontName="Helvetica-Oblique", fontSize=12, textColor="#666666", alignment=TA_CENTER, spaceAfter=30)),
    SP(10),
]

lo_items = [
    B("What is normal wound healing and what can go wrong"),
    B("Different types of healing and wound classification"),
    B("How to manage wounds step-by-step"),
    B("How to prevent and treat bad scars"),
]
story.append(box("Learning Objectives", lo_items))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 1: HAEMOSTASIS & COAGULATION
# ════════════════════════════════════════════════════════════════════════════
story += [H1("1. Haemostasis: Stopping the Bleeding"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Haemostasis:</b> The body's mechanism to stop bleeding", sty_box),
    Paragraph("<b>Platelets:</b> Tiny disc-shaped blood cells that stick together to plug wounds", sty_box),
    Paragraph("<b>Thrombin:</b> A protein that converts fibrinogen into fibrin (the actual clot)", sty_box),
    Paragraph("<b>Fibrin:</b> The strong mesh-like protein that forms the stable blood clot", sty_box),
]))
story.append(SP(6))

story.append(P("When a blood vessel tears, your body must immediately stop the bleeding. This happens in two steps:"))
story += [SP(4),
    Paragraph("<b>Step 1:</b> The damaged vessel squeezes shut (vasoconstriction)", sty_box),
    Paragraph("<b>Step 2:</b> Platelets rush to the injury and glue themselves together, then a chemical cascade converts fibrinogen into fibrin to strengthen the plug", sty_box),
    SP(6),
]

story.append(H3("Coagulation Cascade Flowchart"))
story += [
    flow_step("INJURY: Blood vessel ruptures", C_FLOW2),
    arrow(),
    flow_step("TWO PATHWAYS START:<br/>Intrinsic (from inside blood) + Extrinsic (from tissue damage)", C_FLOW),
    arrow(),
    flow_step("Both converge → Prothrombin converts to THROMBIN", C_FLOW),
    arrow(),
    flow_step("Thrombin converts FIBRINOGEN → FIBRIN<br/>(Fibrin stabilised by Factor XIII)", C_FLOW),
    arrow(),
    flow_step("FIBRIN CLOT FORMED ✓", C_OK),
    SP(8),
]

story += embed_img("img_stages", w=13*cm, cap="Figure 3.2 — The coagulation cascade showing intrinsic, extrinsic and common pathways converging to produce thrombin and fibrin clot.")
story.append(SP(8))

story.append(box("Quick Summary", [
    B("Haemostasis has 2 phases: vessel contraction + platelet plug formation"),
    B("Coagulation cascade is a domino effect converting fibrinogen to stable fibrin clot"),
    B("Completed in seconds to minutes"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 2: INFLAMMATION PHASE
# ════════════════════════════════════════════════════════════════════════════
story += [H1("2. Inflammation: Days 1-3"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Inflammation:</b> Redness, swelling, warmth, pain (signs: rubor, tumor, calor, dolor)", sty_box),
    Paragraph("<b>Neutrophils:</b> First-responder white blood cells that kill bacteria", sty_box),
    Paragraph("<b>Monocytes:</b> White blood cells that become macrophages (the clean-up crew)", sty_box),
    Paragraph("<b>Macrophages:</b> Cells that eat dead tissue and bacteria", sty_box),
]))
story.append(SP(6))

story.append(H3("Inflammation Flowchart"))
story += [
    flow_step("EARLY PHASE (Days 1–2)<br/>Neutrophils arrive → Kill bacteria", C_FLOW2),
    arrow(),
    flow_step("Histamine & serotonin released<br/>→ Blood vessels become leakier<br/>→ More immune cells enter wound", C_FLOW),
    arrow(),
    flow_step("LATE PHASE (Days 2–3)<br/>Monocytes arrive → Become macrophages", C_FLOW),
    arrow(),
    flow_step("Macrophages eat dead tissue & bacteria<br/>(phagocytosis)<br/>Release growth factors →<br/>Trigger next healing stage", C_OK),
    SP(8),
]

story.append(box("Quick Summary", [
    B("Inflammation is the body's defence—it looks bad but is essential"),
    B("Neutrophils kill bacteria; macrophages clean up dead tissue"),
    B("Growth factors released during this phase trigger the next stage (proliferation)"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 3: PROLIFERATION PHASE
# ════════════════════════════════════════════════════════════════════════════
story += [H1("3. Proliferation: Day 3 to 4 Weeks"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Fibroblasts:</b> Cells that make collagen and the structural 'glue' (ground substance)", sty_box),
    Paragraph("<b>Granulation tissue:</b> Pink, bumpy new tissue filling the wound (early proliferation)", sty_box),
    Paragraph("<b>Angiogenesis:</b> Formation of new blood vessels (gives tissue its pink colour)", sty_box),
    Paragraph("<b>Re-epithelialisation:</b> New skin cells migrating from wound edges to cover the surface", sty_box),
]))
story.append(SP(6))

story.append(H3("Proliferation Flowchart"))
story += [
    flow_step("FIBROBLASTS become active<br/>Make ground substance (glue)<br/>+ Collagen fibres", C_FLOW2),
    arrow(),
    flow_step("NEW BLOOD VESSELS grow in<br/>(angiogenesis)<br/>Tissue turns pink & granular", C_FLOW),
    arrow(),
    flow_step("SKIN CELLS migrate inward<br/>from wound edges<br/>(re-epithelialisation)", C_FLOW),
    arrow(),
    flow_step("MYOFIBROBLASTS contract<br/>→ Pull wound edges together", C_OK),
    arrow(),
    flow_step("GRANULATION TISSUE<br/>replaced by scar tissue", C_FLOW2),
    SP(8),
]

story.append(box("Quick Summary", [
    B("4 key processes: collagen, ground substance, new blood vessels, and skin cell migration"),
    B("Granulation tissue (pink, bumpy) is temporary—it will be replaced by scar tissue"),
    B("Wound physically closes during this phase"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 4: REMODELLING PHASE
# ════════════════════════════════════════════════════════════════════════════
story += [H1("4. Remodelling: 2 Weeks to 1+ Year"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Type III collagen:</b> Quick but weak collagen laid down during proliferation", sty_box),
    Paragraph("<b>Type I collagen:</b> Strong, permanent collagen (normal skin is 80% Type I)", sty_box),
    Paragraph("<b>Maturation:</b> Collagen fibres align and cross-link to become stronger", sty_box),
    Paragraph("<b>Scar:</b> Permanent collagen replacement for lost skin—80% strength of original", sty_box),
]))
story.append(SP(6))

story.append(H3("Remodelling Flowchart"))
story += [
    flow_step("Weeks 2–3:<br/>Type III collagen (weak) →<br/>Replaced by Type I (strong)", C_FLOW2),
    arrow(),
    flow_step("Collagen fibres align<br/>like wooden planks<br/>Cross-link for strength", C_FLOW),
    arrow(),
    flow_step("Weeks 3–12:<br/>Tensile strength increases<br/>12 weeks = 80% of normal", C_OK),
    arrow(),
    flow_step("1–2 years:<br/>Scar continues to mature<br/>→ Paler, softer, flatter", C_FLOW2),
    arrow(),
    flow_step("NEVER reaches 100%<br/>of original skin strength", C_WARN),
    SP(8),
]

story.append(box("Quick Summary", [
    B("Weak collagen is replaced by strong collagen; fibres align for strength"),
    B("Maximum strength at ~12 weeks (80% of normal)"),
    B("Scars continue to improve for 1–2 years but never fully match original skin"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 5: NORMAL HEALING IN OTHER TISSUES
# ════════════════════════════════════════════════════════════════════════════
story += [H1("5. Healing in Bone, Nerve & Tendon"), SP(4)]

story.append(H2("5.1 Bone Healing"))
story.append(box("Key Terms", [
    Paragraph("<b>Callus:</b> A temporary bridge of new bone tissue formed at a fracture", sty_box),
    Paragraph("<b>Soft callus:</b> Fibrocartilage (rubbery) stage", sty_box),
    Paragraph("<b>Hard callus:</b> Woven bone (rigid) stage", sty_box),
    Paragraph("<b>Secondary healing:</b> Indirect fracture healing with callus formation", sty_box),
]))
story.append(SP(6))

story.append(H3("Bone Healing Flowchart"))
story += [
    flow_step("Haematoma forms at fracture site<br/>(blood collects, inflammation starts)", C_FLOW2),
    arrow(),
    flow_step("Soft callus: Fibrocartilage bridges the gap<br/>(rubbery, temporary)", C_FLOW),
    arrow(),
    flow_step("Hard callus: Woven bone replaces cartilage<br/>(rigid, stabilises fracture)", C_OK),
    arrow(),
    flow_step("Remodelling: Osteoclasts remove excess bone<br/>Osteoblasts lay lamellar bone<br/>→ Normal shape restored", C_FLOW),
    SP(6),
]

story += embed_img("img_stages", w=12*cm, cap="Figure 3.3 — Stages of bone healing: haematoma → soft callus → hard callus → remodelling.")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Bone heals via callus formation (soft → hard) over weeks to months"),
    B("Remodelling can take months to years to restore normal bone structure"),
]))
story.append(SP(12))

# ── Nerve ────────────────────────────────────────────────────────────────────
story.append(H2("5.2 Nerve Healing"))
story.append(box("Key Terms", [
    Paragraph("<b>Wallerian degeneration:</b> Breakdown of nerve fibres distal (away from) the injury", sty_box),
    Paragraph("<b>Bands of Büngner:</b> Tunnels formed by Schwann cells to guide new nerve fibres", sty_box),
    Paragraph("<b>Axonal regeneration:</b> Growth of new nerve fibres toward their target", sty_box),
    Paragraph("<b>Remyelination:</b> Myelin (insulation) is re-wrapped around the new nerve fibre", sty_box),
]))
story.append(SP(6))

story.append(H3("Nerve Healing Flowchart"))
story += [
    flow_step("INJURY: Nerve is cut or crushed", C_WARN),
    arrow(),
    flow_step("DISTAL END:<br/>Wallerian degeneration<br/>Nerve fibres break down", C_FLOW2),
    arrow(),
    flow_step("Schwann cells clean up debris<br/>Form Bands of Büngner<br/>(tunnels for regrowth)", C_FLOW),
    arrow(),
    flow_step("PROXIMAL END:<br/>Axons grow out<br/>Guided by nerve growth signals", C_OK),
    arrow(),
    flow_step("Axons follow Bands of Büngner<br/>→ Re-myelination<br/>Function restored", C_FLOW),
    SP(6),
]

story += embed_img("img_nerve", w=11*cm, cap="Figure 3.4 — Nerve degeneration and regeneration: (a) normal nerve, (b) Wallerian degeneration, (c) Schwann cells in action, (d) axonal regeneration and remyelination.")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Peripheral nerves degenerate distal to injury, then regenerate from proximal end"),
    B("Schwann cells form guide tunnels for growing axons"),
    B("Recovery takes weeks to months depending on distance to target organ"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 6: ABNORMAL SCARRING
# ════════════════════════════════════════════════════════════════════════════
story += [H1("6. Abnormal Scarring: Hypertrophic vs Keloid"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Hypertrophic scar:</b> Red/raised scar WITHIN original wound boundary; may improve over time", sty_box),
    Paragraph("<b>Keloid scar:</b> Dark/raised scar that EXTENDS BEYOND wound boundary; does not regress spontaneously", sty_box),
    Paragraph("<b>Fibrosis:</b> Excessive collagen production in disorganised pattern", sty_box),
]))
story.append(SP(6))

story.append(H3("Hypertrophic vs Keloid Comparison"))
scar_tbl = Table([
    [Paragraph("Feature", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white")),
     Paragraph("Hypertrophic", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white")),
     Paragraph("Keloid", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white"))],
    [Paragraph("Boundaries", S("t", fontSize=9)),
     Paragraph("Stays WITHIN wound", S("t", fontSize=9)),
     Paragraph("Extends BEYOND wound", S("t", fontSize=9))],
    [Paragraph("Regression", S("t", fontSize=9)),
     Paragraph("Often improves on its own", S("t", fontSize=9)),
     Paragraph("Does NOT regress", S("t", fontSize=9))],
    [Paragraph("Genetics", S("t", fontSize=9)),
     Paragraph("Less genetic link", S("t", fontSize=9)),
     Paragraph("More common in darker skin", S("t", fontSize=9))],
    [Paragraph("Treatment", S("t", fontSize=9)),
     Paragraph("Pressure, silicone, laser", S("t", fontSize=9)),
     Paragraph("Harder to treat; high recurrence", S("t", fontSize=9))],
], colWidths=[4*cm, 6*cm, 6*cm])
scar_tbl.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), HexColor("#C0765A")),
    ('TEXTCOLOR', (0,0), (-1,0), "white"),
    ('BACKGROUND', (0,2), (-1,2), C_BOX),
    ('BACKGROUND', (0,4), (-1,4), C_BOX),
    ('GRID', (0,0), (-1,-1), 0.5, '#ccc'),
    ('ALIGN', (0,0), (-1,-1), 'LEFT'),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
]))
story.append(scar_tbl)
story.append(SP(8))

story += embed_img("img_keloid", w=12*cm, cap="Figure 3.18 — Keloid management algorithm. Light grey = initial treatment; dark grey = secondary options.")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Hypertrophic scars stay within wound boundary; keloids extend beyond"),
    B("Hypertrophic scars often improve; keloids typically need intervention"),
    B("Keloids are more common in darker skin types and require more aggressive treatment"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 7: SCAR CONTRACTURES
# ════════════════════════════════════════════════════════════════════════════
story += [H1("7. Scar Contractures"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Contracture:</b> Scar tissue tightens and shortens, restricting movement", sty_box),
    Paragraph("<b>Z-plasty:</b> Surgical technique to rearrange tissue and lengthen scars", sty_box),
    Paragraph("<b>Functional impairment:</b> Loss of normal joint motion or muscle function", sty_box),
]))
story.append(SP(6))

story.append(P("A contracture happens when scar tissue tightens over time, pulling the surrounding tissues. This can severely limit joint movement or muscle function."))
story.append(SP(4))

story.append(H3("Contracture Management Flowchart"))
story += [
    flow_step("Scar forms across joint or over muscle<br/>(e.g., over elbow, neck, or hand)", C_WARN),
    arrow(),
    flow_step("Scar tissue tightens over weeks/months<br/>→ Pulls skin and underlying tissues<br/>→ Joint movement restricted", C_WARN),
    arrow(),
    flow_step("Physical therapy + splinting<br/>to prevent tightening (early)", C_FLOW),
    arrow(),
    flow_step("If severe:<br/>SURGICAL RELEASE needed<br/>(e.g., Z-plasty, flap surgery)", C_FLOW2),
    arrow(),
    flow_step("Tissue rearranged to lengthen scar<br/>→ Restore motion", C_OK),
    SP(6),
]

story += embed_img("img_scar", w=11*cm, cap="Figure 3.19-3.20 — Neck contracture from chainsaw injury (top); multiple Z-plasty release of finger contracture (bottom).")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Contractures develop when scars tighten across joints or over muscles"),
    B("Early prevention with splinting and therapy is better than surgery"),
    B("Surgical release (Z-plasty, flap surgery) may be needed for severe cases"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 8: WOUND MANAGEMENT PRINCIPLES
# ════════════════════════════════════════════════════════════════════════════
story += [H1("8. Wound Management: Step-by-Step"), SP(4)]

story.append(H3("Complete Wound Management Flowchart"))
story += [
    flow_step("STEP 1: ASSESSMENT<br/>Evaluate patient: trauma type, contamination, fractures, nerve/vessel damage", C_FLOW2),
    arrow(),
    flow_step("STEP 2: PREPARATION<br/>Tetanus prophylaxis + Antibiotics + Analgesia/Anaesthesia", C_FLOW),
    arrow(),
    flow_step("STEP 3: WOUND CARE<br/>Clean irrigation → Remove dead tissue (debridement)<br/>Explore structures → Repair tendons/nerves/vessels<br/>Achieve haemostasis (stop bleeding)", C_FLOW),
    arrow(),
    flow_step("STEP 4: CLOSURE<br/>Primary: Direct suture<br/>Secondary: Leave open to heal<br/>Tertiary: Close later when ready", C_FLOW),
    arrow(),
    flow_step("STEP 5: FOLLOW-UP<br/>Remove sutures at right time<br/>Physiotherapy + Monitor for complications<br/>Scar management", C_OK),
    SP(6),
]

story += embed_img("img_mgmt", w=13*cm, cap="Figure 3.5-3.6 — Wound classification and tetanus post-exposure management algorithm.")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Assessment → Preparation → Wound care → Closure → Follow-up"),
    B("Debridement removes dead/contaminated tissue for better healing"),
    B("Closure method depends on wound type and patient factors"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 9: DEGLOVING INJURIES
# ════════════════════════════════════════════════════════════════════════════
story += [H1("9. Degloving Injuries"), SP(4)]

story.append(box("Key Terms", [
    Paragraph("<b>Degloving:</b> Skin and fat are stripped/peeled away from underlying muscle/bone", sty_box),
    Paragraph("<b>Open degloving:</b> Obvious skin loss (e.g., finger torn off)", sty_box),
    Paragraph("<b>Closed degloving (Morel-Lavallée):</b> Skin looks intact but subcutaneous tissue is sheared underneath", sty_box),
]))
story.append(SP(6))

story.append(H3("Degloving Flowchart"))
story += [
    flow_step("INJURY: Shearing force or avulsion<br/>(e.g., crush in machinery, motor vehicle collision)", C_WARN),
    arrow(),
    flow_step("OPEN DEGLOVING:<br/>Visible skin loss<br/>Usually obvious", C_WARN),
    arrow(),
    flow_step("CLOSED DEGLOVING:<br/>Skin appears normal<br/>BUT subcutaneous tissue sheared underneath<br/>(Fluid-filled space = Morel-Lavallée)", C_WARN),
    arrow(),
    flow_step("ASSESS TISSUE VIABILITY<br/>Staining, perfusion, bleeding", C_FLOW),
    arrow(),
    flow_step("SERIAL DEBRIDEMENT<br/>Remove non-viable tissue<br/>RECONSTRUCTION OPTIONS<br/>(skin graft, flap, or amputation in severe cases)", C_FLOW2),
    SP(6),
]

story += embed_img("img_dglv", w=11*cm, cap="Figure 3.9-3.12 — Degloving injuries: (top) open degloving of fingers; (bottom) Morel-Lavallée lesion with sheared subcutaneous tissue.")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Open degloving: visible skin loss. Closed degloving: skin intact but tissue sheared underneath"),
    B("Closed degloving (Morel-Lavallée) easily missed on first exam—always suspect with high-impact trauma"),
    B("Treatment: debride non-viable tissue + plan reconstruction"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 10: COMPARTMENT SYNDROME & NECROTISING FASCIITIS
# ════════════════════════════════════════════════════════════════════════════
story += [H1("10. Surgical Emergencies: Compartment Syndrome & Fasciitis"), SP(4)]

story.append(H2("10.1 Acute Compartment Syndrome"))
story.append(box("Key Terms", [
    Paragraph("<b>Compartment syndrome:</b> Increased pressure in a closed muscle compartment → blood supply cut off", sty_box),
    Paragraph("<b>Ischaemia:</b> Lack of blood flow; muscles start to die", sty_box),
    Paragraph("<b>Fasciotomy:</b> Emergency surgical cuts to release the pressure", sty_box),
]))
story.append(SP(6))

story.append(H3("Compartment Syndrome Flowchart"))
story += [
    flow_step("CAUSE: Fracture, crush, burn, or severe trauma<br/>→ Bleeding/swelling inside compartment", C_WARN),
    arrow(),
    flow_step("Pressure builds in tight fascial sheath<br/>→ Cuts off blood supply<br/>→ SURGICAL EMERGENCY", C_WARN),
    arrow(),
    flow_step("CLASSIC SIGNS:<br/>• Pain OUT OF PROPORTION to injury<br/>• Pain with PASSIVE muscle stretch<br/>• Paraesthesia (pins & needles)", C_WARN),
    arrow(),
    flow_step("DIAGNOSIS: Clinical exam +<br/>Measure intracompartmental pressure<br/>(≥30 mmHg = threshold)", C_FLOW),
    arrow(),
    flow_step("TREATMENT: EMERGENCY FASCIOTOMY<br/>(Long incisions to release pressure)<br/>MUST BE DONE WITHIN HOURS", C_WARN),
    arrow(),
    flow_step("IF DELAYED: Rhabdomyolysis,<br/>permanent muscle damage, amputation, death", C_WARN),
    SP(6),
]

story.append(box("Quick Summary", [
    B("Compartment syndrome is a SURGICAL EMERGENCY—pain > injury severity is a red flag"),
    B("Passive stretch pain + paraesthesia are key diagnostic signs"),
    B("Fasciotomy must be done within hours to prevent permanent disability"),
]))
story.append(SP(8))

# ── Necrotising Fasciitis ─────────────────────────────────────────────────────
story.append(H2("10.2 Necrotising Fasciitis"))
story.append(box("Key Terms", [
    Paragraph("<b>Necrotising fasciitis:</b> Rapidly spreading infection of skin, subcutaneous tissue, and fascia (flesh-eating disease)", sty_box),
    Paragraph("<b>Crepitus:</b> Crackling sound under skin from gas-producing bacteria", sty_box),
    Paragraph("<b>Rhabdomyolysis:</b> Muscle tissue breaks down, releasing myoglobin into bloodstream (kidney damage risk)", sty_box),
]))
story.append(SP(6))

story.append(H3("Necrotising Fasciitis Flowchart"))
story += [
    flow_step("CAUSE: Bacteria enter through wound<br/>Streptococcus pyogenes most common<br/>(Also: Staph, E. coli, Clostridium)", C_WARN),
    arrow(),
    flow_step("RAPID SPREAD through tissue planes<br/>Massive inflammation & tissue death<br/>Septic shock develops", C_WARN),
    arrow(),
    flow_step("CLASSIC SIGNS:<br/>• Disproportionate pain<br/>• Dishwater drainage<br/>• Crepitus (gas bubbles)<br/>• Fever, shock, multi-organ failure", C_WARN),
    arrow(),
    flow_step("DIAGNOSIS: CLINICAL<br/>Do NOT wait for culture results<br/>Imaging may show gas in tissue", C_FLOW),
    arrow(),
    flow_step("TREATMENT: EMERGENCY<br/>• IV broad-spectrum antibiotics NOW<br/>• RADICAL SURGICAL DEBRIDEMENT<br/>→ Remove ALL infected/dead tissue<br/>• 'Second look' surgery in 24–48h", C_WARN),
    arrow(),
    flow_step("Multiple debridements may be needed<br/>until infection cleared<br/>Then reconstruction", C_FLOW2),
    SP(6),
]

story += embed_img("img_comp", w=11*cm, cap="Figure 3.13-3.14 — Fasciotomy of the leg (top); necrotising fasciitis with tissue destruction (bottom).")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Necrotising fasciitis is a SURGICAL EMERGENCY with high mortality (26-40%)"),
    B("Clinical diagnosis is key—don't wait for culture results; start antibiotics + surgery immediately"),
    B("Radical debridement (removing all dead tissue) is essential; multiple surgeries often needed"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# TOPIC 11: CHRONIC WOUNDS & PRESSURE ULCERS
# ════════════════════════════════════════════════════════════════════════════
story += [H1("11. Chronic Wounds: Leg Ulcers & Pressure Ulcers"), SP(4)]

story.append(H2("11.1 Leg Ulcers"))
story.append(box("Key Terms", [
    Paragraph("<b>Leg ulcer:</b> Break in skin on lower leg that fails to heal normally", sty_box),
    Paragraph("<b>Venous ulcer:</b> From poor vein function (most common)", sty_box),
    Paragraph("<b>Arterial ulcer:</b> From poor artery blood flow", sty_box),
    Paragraph("<b>Diabetes ulcer:</b> From nerve damage + poor blood flow", sty_box),
]))
story.append(SP(6))

story.append(P("Chronic leg ulcers fail to progress through normal healing stages. They get stuck in a prolonged inflammatory phase with persistent infections. Treatment: address underlying cause (venous insufficiency, arterial blockage, diabetes), debride dead tissue, use appropriate dressings, and elevate the leg."))
story.append(SP(6))

story.append(H2("11.2 Pressure Ulcers (Pressure Injuries)"))
story.append(box("Key Terms", [
    Paragraph("<b>Pressure ulcer:</b> Tissue damage from sustained pressure over bony prominence", sty_box),
    Paragraph("<b>Ischaemia:</b> Lack of blood flow from prolonged pressure", sty_box),
    Paragraph("<b>Stage:</b> Classification from 1 (superficial) to 4 (full-thickness + bone)", sty_box),
]))
story.append(SP(6))

story.append(H3("Pressure Ulcer Development Flowchart"))
story += [
    flow_step("PATIENT: Immobile or bedbound<br/>(Severe illness, spinal injury, etc.)", C_WARN),
    arrow(),
    flow_step("Sustained pressure over bone<br/>(Sacrum, heel, hip, etc.)", C_WARN),
    arrow(),
    flow_step("STAGE 1: Non-blanchable redness<br/>Skin intact but red", C_FLOW2),
    arrow(),
    flow_step("STAGE 2: Partial-thickness skin loss<br/>Dermis exposed", C_FLOW),
    arrow(),
    flow_step("STAGE 3: Full-thickness skin loss<br/>(Subcutaneous fat visible)", C_FLOW),
    arrow(),
    flow_step("STAGE 4: Full-thickness loss<br/>Bone, muscle, or tendon exposed<br/>HIGH infection risk", C_WARN),
    SP(6),
]

story.append(box("Prevention is Better Than Treatment", [
    B("Risk scoring: Braden Scale, Waterlow Score, or Norton Scale"),
    B("Reposition patient every 2–4 hours"),
    B("Pressure-redistributing mattress/cushion"),
    B("Nutritional support + maintain clean, dry skin"),
    B("Early mobility when possible"),
]))
story.append(SP(6))

story += embed_img("img_close", w=10*cm, cap="Figure 3.15 — Pressure ulcer showing full-thickness tissue loss.")
story.append(SP(6))

story.append(box("Quick Summary", [
    B("Pressure ulcers are largely PREVENTABLE through repositioning and pressure relief"),
    B("Stage 1-4 classification guides treatment (early stages may heal with care; Stage 4 requires surgery)"),
    B("Nutritional support and mobility are critical for healing"),
]))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# QUICK REFERENCE TABLE
# ════════════════════════════════════════════════════════════════════════════
story += [H1("Quick Reference: All Healing Phases at a Glance"), SP(6)]

ref_tbl = Table([
    [Paragraph("Phase", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white")),
     Paragraph("Timeframe", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white")),
     Paragraph("Key Events", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white")),
     Paragraph("Key Cells", S("th", fontName="Helvetica-Bold", fontSize=9, textColor="white"))],
    [Paragraph("Haemostasis", S("t", fontSize=8.5)),
     Paragraph("0–min", S("t", fontSize=8.5)),
     Paragraph("Platelets clump; fibrin clot forms", S("t", fontSize=8.5)),
     Paragraph("Platelets, RBCs", S("t", fontSize=8.5))],
    [Paragraph("Inflammation", S("t", fontSize=8.5)),
     Paragraph("0–3 days", S("t", fontSize=8.5)),
     Paragraph("Neutrophils kill bacteria; macrophages clean up", S("t", fontSize=8.5)),
     Paragraph("Neutrophils, macrophages", S("t", fontSize=8.5))],
    [Paragraph("Proliferation", S("t", fontSize=8.5)),
     Paragraph("3 days–4 wks", S("t", fontSize=8.5)),
     Paragraph("Collagen, new blood vessels, new skin; wound closes", S("t", fontSize=8.5)),
     Paragraph("Fibroblasts, endothelial cells", S("t", fontSize=8.5))],
    [Paragraph("Remodelling", S("t", fontSize=8.5)),
     Paragraph("2 wks–1+ yr", S("t", fontSize=8.5)),
     Paragraph("Collagen remodelled; scar matures; strength peaks at 12 wks (80%)", S("t", fontSize=8.5)),
     Paragraph("Fibroblasts, osteoclasts", S("t", fontSize=8.5))],
], colWidths=[3.2*cm, 2.8*cm, 5*cm, 4*cm])
ref_tbl.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), HexColor("#C0765A")),
    ('TEXTCOLOR', (0,0), (-1,0), "white"),
    ('BACKGROUND', (0,2), (-1,2), C_BOX),
    ('BACKGROUND', (0,4), (-1,4), C_BOX),
    ('GRID', (0,0), (-1,-1), 0.5, '#ccc'),
    ('ALIGN', (0,0), (-1,-1), 'LEFT'),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('LEFTPADDING', (0,0), (-1,-1), 5),
    ('RIGHTPADDING', (0,0), (-1,-1), 5),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
]))
story.append(ref_tbl)
story.append(SP(20))

story.append(Paragraph("End of Chapter 3 — Wound Healing and Tissue Repair", S("end", fontName="Helvetica-Oblique", fontSize=9, textColor="#888888", alignment=TA_CENTER)))

# ────────────────────────────────────────────────────────────────────────────
def footer(canvas, doc):
    canvas.saveState()
    canvas.setFont("Helvetica", 7.5)
    canvas.setFillColor(HexColor("#888888"))
    canvas.drawString(L_M, 1*cm, "Chapter 3 — Wound Healing and Tissue Repair")
    canvas.drawRightString(PAGE_W - R_M, 1*cm, f"Page {doc.page}")
    canvas.restoreState()

doc = SimpleDocTemplate(OUT, pagesize=A4, leftMargin=L_M, rightMargin=R_M, topMargin=T_M, bottomMargin=B_M + 0.6*cm)
doc.build(story, onFirstPage=footer, onLaterPages=footer)
print(f"\n✓ PDF built: {OUT}")

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/wound-v2/build_v2.py'