from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether
)
from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_JUSTIFY

OUTPUT = "/tmp/workspace/necrosis-notes/Tissue_Necrosis_5mark_Notes.pdf"

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=1.8*cm,
    leftMargin=1.8*cm,
    topMargin=1.5*cm,
    bottomMargin=1.5*cm,
)

# ── Colour palette ────────────────────────────────────────────────────────────
NAVY   = colors.HexColor("#1a3a5c")
TEAL   = colors.HexColor("#0d6e7a")
GOLD   = colors.HexColor("#e6a817")
LIGHT  = colors.HexColor("#eaf4f6")
PINK   = colors.HexColor("#fff0f3")
WHITE  = colors.white
DARK   = colors.HexColor("#1c1c1c")
GRAY   = colors.HexColor("#555555")

styles = getSampleStyleSheet()

# Custom styles
title_style = ParagraphStyle(
    "Title", parent=styles["Normal"],
    fontName="Helvetica-Bold", fontSize=18,
    textColor=WHITE, alignment=TA_CENTER,
    spaceAfter=4, leading=22
)
subtitle_style = ParagraphStyle(
    "Subtitle", parent=styles["Normal"],
    fontName="Helvetica", fontSize=10,
    textColor=colors.HexColor("#cce8ec"), alignment=TA_CENTER,
    spaceAfter=0
)
h1 = ParagraphStyle(
    "H1", parent=styles["Normal"],
    fontName="Helvetica-Bold", fontSize=13,
    textColor=WHITE, leading=17,
    spaceBefore=4, spaceAfter=3
)
h2 = ParagraphStyle(
    "H2", parent=styles["Normal"],
    fontName="Helvetica-Bold", fontSize=10.5,
    textColor=NAVY, leading=14,
    spaceBefore=5, spaceAfter=2
)
body = ParagraphStyle(
    "Body", parent=styles["Normal"],
    fontName="Helvetica", fontSize=9.5,
    textColor=DARK, leading=13.5,
    spaceAfter=2, leftIndent=6
)
bullet_style = ParagraphStyle(
    "Bullet", parent=styles["Normal"],
    fontName="Helvetica", fontSize=9.5,
    textColor=DARK, leading=13,
    spaceAfter=1.5,
    leftIndent=14, firstLineIndent=-8
)
bold_label = ParagraphStyle(
    "BoldLabel", parent=styles["Normal"],
    fontName="Helvetica-Bold", fontSize=9.5,
    textColor=TEAL, leading=13,
    spaceAfter=1.5, leftIndent=6
)
note_style = ParagraphStyle(
    "Note", parent=styles["Normal"],
    fontName="Helvetica-Oblique", fontSize=9,
    textColor=colors.HexColor("#7a4000"), leading=12,
    spaceAfter=1, leftIndent=10,
    backColor=colors.HexColor("#fff8e7")
)

def section_header(title, color=TEAL):
    """Returns a coloured section header block."""
    data = [[Paragraph(f'<font color="white"><b>{title}</b></font>', h1)]]
    t = Table(data, colWidths=[17*cm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), color),
        ("ROUNDEDCORNERS", [4,4,4,4]),
        ("TOPPADDING", (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 5),
        ("LEFTPADDING", (0,0), (-1,-1), 10),
    ]))
    return t

def sub_header(title):
    data = [[Paragraph(f'<b>{title}</b>', ParagraphStyle(
        "sh", fontName="Helvetica-Bold", fontSize=10, textColor=WHITE,
        leading=13
    ))]]
    t = Table(data, colWidths=[17*cm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), NAVY),
        ("TOPPADDING", (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING", (0,0), (-1,-1), 14),
    ]))
    return t

def bp(text):
    return Paragraph(f"• {text}", bullet_style)

def lbl(label, text):
    return Paragraph(f'<b><font color="#0d6e7a">{label}:</font></b> {text}', body)

story = []

# ══════════════════════════════════════════════════════════════════════════════
# TITLE PAGE HEADER
# ══════════════════════════════════════════════════════════════════════════════
title_data = [[
    Paragraph("TISSUE NECROSIS &amp; APOPTOSIS", title_style),
    Paragraph("Quick 5-Mark Revision Notes  |  Pathology", subtitle_style),
]]
title_table = Table([[
    Paragraph("TISSUE NECROSIS &amp; APOPTOSIS", title_style),
]], colWidths=[17*cm])
title_table.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,-1), NAVY),
    ("TOPPADDING", (0,0), (-1,-1), 10),
    ("BOTTOMPADDING", (0,0), (-1,-1), 4),
    ("LEFTPADDING", (0,0), (-1,-1), 10),
    ("ROUNDEDCORNERS", [6,6,6,6]),
]))
subtitle_table = Table([[
    Paragraph("Quick 5-Mark Revision Notes  |  Pathology", subtitle_style),
]], colWidths=[17*cm])
subtitle_table.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,-1), TEAL),
    ("TOPPADDING", (0,0), (-1,-1), 4),
    ("BOTTOMPADDING", (0,0), (-1,-1), 6),
    ("LEFTPADDING", (0,0), (-1,-1), 10),
]))

story.append(title_table)
story.append(subtitle_table)
story.append(Spacer(1, 0.3*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 1. COAGULATIVE NECROSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("1.  COAGULATIVE NECROSIS"))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Common type; <b>outline of dead tissue is preserved</b> for few days. Localised area = <b>Infarct</b>."))
story.append(lbl("Causes", "Ischemia (vessel obstruction), potent bacterial toxins, phenol, mercury, corrosive chemicals."))
story.append(Spacer(1, 0.1*cm))

story.append(sub_header("Gross"))
story.append(bp("<b>Organs:</b> All organs <i>except brain</i>. Most common: heart, kidney, spleen."))
story.append(bp("<b>Appearance:</b> Opaque, like boiled meat. Tissue is <b>dry, pale, yellow and soft</b>."))

story.append(sub_header("Microscopy"))
story.append(bp("Outline of dead tissue preserved for some days."))
story.append(bp("Nuclear changes (pyknosis, karyorrhexis, karyolysis) + cytoplasmic changes."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 2. LIQUEFACTIVE (COLLIQUATIVE) NECROSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("2.  LIQUEFACTIVE (COLLIQUATIVE) NECROSIS"))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Dead tissue <b>rapidly softens</b> and transforms into a liquid viscous mass."))
story.append(lbl("Causes", None))
story.append(bp("Ischemic injury to CNS (brain)."))
story.append(bp("<b>Suppurative infections:</b> Focal bacterial infections stimulate leukocyte accumulation."))
story.append(Spacer(1, 0.1*cm))

story.append(sub_header("Gross"))
story.append(bp("<b>Organs:</b> Brain, abscess (any organ/tissue). Necrotic area is soft, center liquefied."))

story.append(sub_header("Microscopy — Abscess"))
story.append(bp("<b>Abscess</b> = localised collection of pus; cavity containing pus formed by liquefactive necrosis + inflammatory cells."))
story.append(bp("Pus = liquefied necrotic cell debris + dead leukocytes + macrophages."))
story.append(bp("Abscess shows a cavity with pus, surrounded by granulation tissue + inflammatory cells."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 3. CASEOUS NECROSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("3.  CASEOUS NECROSIS"))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Distinctive type with <b>combined features of coagulative &amp; liquefactive necrosis</b>."))
story.append(lbl("Cause", "Characteristic of <b>Tuberculosis</b>; due to hypersensitivity reaction. Most common site: TB lymph node."))
story.append(Spacer(1, 0.1*cm))

story.append(sub_header("Gross"))
story.append(bp("<b>Organs:</b> Any organ in TB; most common: <b>lung &amp; lymph nodes</b>."))
story.append(bp("<b>Appearance:</b> Yellowish-white, soft, granular, friable, sharply circumscribed."))
story.append(bp("Necrotic tissue resembles dry/crumby <b>cheese</b> — hence the name 'caseous' (cheese-like)."))

story.append(sub_header("Microscopy"))
story.append(bp("Focal lesion = <b>Granuloma</b> (tuberculous granuloma / tubercle)."))
story.append(bp("Granulomas may be <b>caseating</b> (soft granuloma) or <b>non-caseating</b> (hard granuloma)."))
story.append(bp("Caseating granulomas: central area of caseous necrosis — shapeless, eosinophilic, granular material."))
story.append(bp("Necrotic area surrounded by: <b>epithelioid cells + Langhans giant cells</b> (horseshoe nuclei) + lymphocytes + fibroblasts."))
story.append(bp("Caseous material may undergo <b>dystrophic calcification</b>."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 4. FAT NECROSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("4.  FAT NECROSIS"))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Focal areas of fat destruction affecting <b>adipose tissue</b>."))
story.append(lbl("Types", "<b>Enzymatic</b> (most common) and <b>Traumatic</b>."))
story.append(Spacer(1, 0.1*cm))

story.append(sub_header("A. Enzymatic Fat Necrosis"))
story.append(bp("Peculiar to adipose tissue around the <b>acutely inflamed pancreas (acute pancreatitis)</b>."))
story.append(bp("<b>Mechanism:</b> Pancreatic enzymes leak from injured acinar cells → fat cell damage → lipase destroys fat cells → free fatty acids released → combine with calcium → precipitated as <b>calcium soaps (fat saponification)</b>."))
story.append(bp("<b>Gross:</b> <b>Chalky-white areas</b>."))
story.append(bp("<b>Microscopy:</b> Fat cells with pale, shadowy outlines surrounded by inflammatory reaction."))

story.append(sub_header("B. Traumatic Fat Necrosis"))
story.append(bp("Occurs in tissues with <b>high fat content</b> (breast, thigh) following <b>severe trauma</b>."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 5. FIBRINOID NECROSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("5.  FIBRINOID NECROSIS"))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Special form; deposition of <b>pink-staining (fibrin-like) proteinaceous material</b>."))
story.append(lbl("Sites", "Arteries, arterioles, glomeruli of kidney."))
story.append(lbl("Cause", "Usually seen in <b>immune-mediated vascular injury</b> (immune complex vasculitis)."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 6. GANGRENE
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("6.  GANGRENE (GANGRENOUS NECROSIS)"))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Massive necrosis with <b>superadded putrefaction</b> (bacterial decomposition → foul-smelling gases)."))
story.append(Spacer(1, 0.1*cm))

story.append(sub_header("A. Dry Gangrene — 'Foot Dry Gangrene'"))
story.append(bp("<b>Cause:</b> Arterial occlusion (e.g., atherosclerosis)."))
story.append(bp("<b>Sites:</b> Limbs, distal lower limb (leg, foot, toes)."))
story.append(bp("<b>Gross:</b> Dry, shrunken, shriveled (<i>mummified</i>), dark brown/black. <b>Clear line of demarcation</b> present."))
story.append(bp("<b>Microscopy:</b> Smudging of soft tissue/skin; line of demarcation = granulation tissue + inflammatory cells."))

story.append(sub_header("B. Wet Gangrene — 'Diabetic Foot'"))
story.append(bp("<b>Sites:</b> Moist tissues/organs: bowel, lung, mouth."))
story.append(bp("<b>Cause:</b> Usually <b>venous blockage</b> (strangulated hernia, intussusception, volvulus). In <b>diabetics</b> — high sugar favours bacterial growth."))
story.append(bp("<b>Gross:</b> Soft, swollen, putrid, rotten, dark. <b>No clear line of demarcation</b>."))
story.append(bp("<b>Microscopy:</b> Liquefactive type of necrosis."))

story.append(sub_header("C. Gas Gangrene"))
story.append(bp("Special type of wet gangrene caused by <b>gas-forming anaerobic Clostridia</b>."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# DRY vs WET GANGRENE TABLE
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("DRY vs WET GANGRENE — Comparison Table", NAVY))
story.append(Spacer(1, 0.2*cm))

header_style = ParagraphStyle("th", fontName="Helvetica-Bold", fontSize=9, textColor=WHITE, alignment=TA_CENTER, leading=12)
cell_style   = ParagraphStyle("td", fontName="Helvetica", fontSize=9, textColor=DARK, alignment=TA_LEFT, leading=12)
feat_style   = ParagraphStyle("tf", fontName="Helvetica-Bold", fontSize=9, textColor=NAVY, alignment=TA_LEFT, leading=12)

table_data = [
    [Paragraph("Feature", header_style), Paragraph("DRY", header_style), Paragraph("WET", header_style)],
    [Paragraph("Common site", feat_style), Paragraph("Limbs", cell_style), Paragraph("Bowels", cell_style)],
    [Paragraph("Example", feat_style), Paragraph("Atherosclerotic occlusion", cell_style), Paragraph("Volvulus, intussusception", cell_style)],
    [Paragraph("Cause of ischemia", feat_style), Paragraph("Arterial obstruction", cell_style), Paragraph("Commonly venous obstruction", cell_style)],
    [Paragraph("Rate of obstruction", feat_style), Paragraph("Slow", cell_style), Paragraph("Abrupt", cell_style)],
    [Paragraph("Pathogens", feat_style), Paragraph("Absent", cell_style), Paragraph("May be present / causative", cell_style)],
    [Paragraph("Appearance", feat_style), Paragraph("Shriveled, dry (mummified), black", cell_style), Paragraph("Swollen, soft, moist", cell_style)],
    [Paragraph("Line of demarcation", feat_style), Paragraph("Clear cut", cell_style), Paragraph("Not clear cut", cell_style)],
    [Paragraph("Putrefaction", feat_style), Paragraph("Minimal", cell_style), Paragraph("Marked, may be foul", cell_style)],
    [Paragraph("Spread", feat_style), Paragraph("Slow", cell_style), Paragraph("Rapid", cell_style)],
    [Paragraph("Prognosis", feat_style), Paragraph("Fair", cell_style), Paragraph("Poor (severe septicemia)", cell_style)],
]

col_w = [5*cm, 5.8*cm, 6.2*cm]
comp_table = Table(table_data, colWidths=col_w, repeatRows=1)
comp_table.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,0), TEAL),
    ("BACKGROUND", (0,1), (-1,-1), colors.white),
    ("ROWBACKGROUNDS", (0,1), (-1,-1), [colors.white, LIGHT]),
    ("GRID", (0,0), (-1,-1), 0.5, colors.HexColor("#b0d0d8")),
    ("TOPPADDING", (0,0), (-1,-1), 5),
    ("BOTTOMPADDING", (0,0), (-1,-1), 5),
    ("LEFTPADDING", (0,0), (-1,-1), 6),
    ("RIGHTPADDING", (0,0), (-1,-1), 6),
    ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(comp_table)
story.append(Spacer(1, 0.3*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 7. GUMMATOUS NECROSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("7.  GUMMATOUS NECROSIS"))
story.append(Spacer(1, 0.15*cm))

story.append(bp("Necrotic tissue is <b>firm and rubbery</b>; original architecture visible on histology."))
story.append(bp("Characteristically found in <b>Syphilis</b>."))
story.append(Spacer(1, 0.25*cm))

# ══════════════════════════════════════════════════════════════════════════════
# 8. APOPTOSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("8.  APOPTOSIS", colors.HexColor("#7b1c2e")))
story.append(Spacer(1, 0.15*cm))

story.append(lbl("Definition", "Programmed cell death — cells <b>activate enzymes that degrade nuclear DNA and cytoplasmic proteins</b>."))
story.append(Spacer(1, 0.1*cm))

story.append(sub_header("Causes of Apoptosis"))

story.append(Paragraph("<b>A. Physiological Situations</b>", bold_label))
story.append(bp("Removal of excess cells during embryogenesis (e.g., disappearance of webbing between fingers/toes)."))
story.append(bp("Elimination of cells after hormonal stimulus (e.g., endometrial shedding)."))
story.append(bp("Deletion of autoreactive lymphocytes."))
story.append(bp("Cell death after immune response (killing by CTLs)."))

story.append(Paragraph("<b>B. Pathological Situations</b>", bold_label))
story.append(bp("DNA damage (radiation, cytotoxic drugs, free radicals)."))
story.append(bp("Accumulation of misfolded proteins."))
story.append(bp("Cell death in certain infections (viral hepatitis, HIV)."))
story.append(bp("Atrophy of hormone-sensitive tissue on hormone withdrawal."))
story.append(Spacer(1, 0.15*cm))

story.append(sub_header("Key Features of Apoptosis"))
apop_feats = [
    ["Feature", "Detail"],
    ["Cell size", "Shrinks (vs necrosis: swells)"],
    ["Nucleus", "Chromatin condensation (pyknosis) → fragmentation"],
    ["Membrane", "Intact (no rupture, unlike necrosis)"],
    ["Inflammation", "Absent (phagocytosis by macrophages)"],
    ["Energy", "ATP-dependent (active process)"],
    ["Bodies", "Apoptotic bodies formed, phagocytosed"],
]
feat_h = ParagraphStyle("fh", fontName="Helvetica-Bold", fontSize=9, textColor=WHITE, alignment=TA_CENTER, leading=12)
feat_c = ParagraphStyle("fc", fontName="Helvetica", fontSize=9, textColor=DARK, leading=12)
feat_bold = ParagraphStyle("fb", fontName="Helvetica-Bold", fontSize=9, textColor=NAVY, leading=12)

apop_data = [[Paragraph(r[0], feat_h if i==0 else feat_bold),
              Paragraph(r[1], feat_h if i==0 else feat_c)]
             for i, r in enumerate(apop_feats)]

apop_table = Table(apop_data, colWidths=[5*cm, 12*cm])
apop_table.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,0), colors.HexColor("#7b1c2e")),
    ("ROWBACKGROUNDS", (0,1), (-1,-1), [PINK, colors.white]),
    ("GRID", (0,0), (-1,-1), 0.5, colors.HexColor("#e8b0ba")),
    ("TOPPADDING", (0,0), (-1,-1), 5),
    ("BOTTOMPADDING", (0,0), (-1,-1), 5),
    ("LEFTPADDING", (0,0), (-1,-1), 7),
    ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(apop_table)
story.append(Spacer(1, 0.3*cm))

# ══════════════════════════════════════════════════════════════════════════════
# QUICK RECALL BOX
# ══════════════════════════════════════════════════════════════════════════════
story.append(section_header("QUICK RECALL — Exam Tips", GOLD))
story.append(Spacer(1, 0.15*cm))

tips = [
    ("Coagulative", "All organs EXCEPT brain | Outline preserved | Like boiled meat"),
    ("Liquefactive", "Brain ischemia + suppurative infections | Abscess = pus collection"),
    ("Caseous", "TB only | Cheese-like | Granuloma with Langhans giant cells"),
    ("Fat necrosis", "Enzymatic = pancreatitis + chalky white | Traumatic = breast/thigh"),
    ("Fibrinoid", "Immune complex vasculitis | Arteries + glomeruli | Pink fibrin deposits"),
    ("Gangrene", "Dry = arterial, mummified, line of demarcation | Wet = venous, no line"),
    ("Gas gangrene", "Wet type | Anaerobic Clostridia"),
    ("Gummatous", "Syphilis | Firm &amp; rubbery"),
    ("Apoptosis", "Programmed, ATP-dependent, NO inflammation, apoptotic bodies"),
]
tip_label = ParagraphStyle("tl", fontName="Helvetica-Bold", fontSize=9, textColor=colors.HexColor("#7a4000"), leading=12)
tip_body  = ParagraphStyle("tb", fontName="Helvetica", fontSize=9, textColor=DARK, leading=12)

tip_data = [[Paragraph(t[0], tip_label), Paragraph(t[1], tip_body)] for t in tips]
tip_table = Table(tip_data, colWidths=[4.5*cm, 12.5*cm])
tip_table.setStyle(TableStyle([
    ("ROWBACKGROUNDS", (0,0), (-1,-1), [colors.HexColor("#fff8e7"), colors.HexColor("#fff3cc")]),
    ("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#e6a817")),
    ("TOPPADDING", (0,0), (-1,-1), 4),
    ("BOTTOMPADDING", (0,0), (-1,-1), 4),
    ("LEFTPADDING", (0,0), (-1,-1), 6),
    ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(tip_table)
story.append(Spacer(1, 0.3*cm))

# Footer note
story.append(HRFlowable(width="100%", thickness=0.5, color=TEAL))
story.append(Paragraph(
    "<i>Notes compiled from textbook source — for 5-mark exam preparation in Pathology.</i>",
    ParagraphStyle("footer", fontName="Helvetica-Oblique", fontSize=8,
                   textColor=GRAY, alignment=TA_CENTER, spaceBefore=4)
))

# Build PDF
doc.build(story)
print(f"PDF saved to: {OUTPUT}")