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

OUTPUT = "/home/daytona/workspace/peptic-ulcer-pdf/Peptic_Ulcer_Quick_Reference.pdf"

# ── Colours ──────────────────────────────────────────────────────────────────
NAVY      = colors.HexColor("#1B3A6B")
STEEL     = colors.HexColor("#2E6DA4")
TEAL      = colors.HexColor("#1A7A6E")
ORANGE    = colors.HexColor("#E07B2A")
RED       = colors.HexColor("#C0392B")
GREEN     = colors.HexColor("#1E7F45")
PURPLE    = colors.HexColor("#6C3483")
YELLOW_BG = colors.HexColor("#FFF8E1")
BLUE_BG   = colors.HexColor("#E8F4FD")
GREEN_BG  = colors.HexColor("#E8F8F0")
RED_BG    = colors.HexColor("#FDEDEC")
GRAY_BG   = colors.HexColor("#F5F5F5")
LIGHT_GRAY= colors.HexColor("#ECEFF1")
WHITE     = colors.white
BLACK     = colors.HexColor("#212121")

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

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

COVER_TITLE = S("CoverTitle", fontSize=28, textColor=WHITE,
                leading=34, alignment=TA_CENTER, fontName="Helvetica-Bold")
COVER_SUB   = S("CoverSub", fontSize=13, textColor=colors.HexColor("#CFE2FF"),
                leading=18, alignment=TA_CENTER, fontName="Helvetica")
COVER_META  = S("CoverMeta", fontSize=10, textColor=colors.HexColor("#AED6F1"),
                leading=14, alignment=TA_CENTER, fontName="Helvetica-Oblique")

SEC_HEAD = S("SecHead", fontSize=13, textColor=WHITE,
             leading=17, fontName="Helvetica-Bold", alignment=TA_LEFT)
SUBSEC   = S("SubSec", fontSize=11, textColor=NAVY,
             leading=15, fontName="Helvetica-Bold", spaceBefore=6)
BODY     = S("Body", fontSize=9, textColor=BLACK,
             leading=14, fontName="Helvetica", alignment=TA_JUSTIFY)
BULLET   = S("Bullet", fontSize=9, textColor=BLACK,
             leading=13, fontName="Helvetica", leftIndent=12,
             firstLineIndent=-10)
SMALL    = S("Small", fontSize=8, textColor=colors.HexColor("#555555"),
             leading=11, fontName="Helvetica-Oblique", alignment=TA_CENTER)
TBL_HEAD = S("TblHead", fontSize=9, textColor=WHITE,
             leading=12, fontName="Helvetica-Bold", alignment=TA_CENTER)
TBL_CELL = S("TblCell", fontSize=8.5, textColor=BLACK,
             leading=12, fontName="Helvetica", alignment=TA_LEFT)
TBL_CELL_C = S("TblCellC", fontSize=8.5, textColor=BLACK,
               leading=12, fontName="Helvetica", alignment=TA_CENTER)
BADGE    = S("Badge", fontSize=8, textColor=WHITE,
             leading=11, fontName="Helvetica-Bold", alignment=TA_CENTER)
FLOW_TEXT= S("FlowText", fontSize=8.5, textColor=BLACK,
             leading=12, fontName="Helvetica", alignment=TA_CENTER)
WARN     = S("Warn", fontSize=9, textColor=RED,
             leading=13, fontName="Helvetica-Bold")
FOOTER   = S("Footer", fontSize=7.5, textColor=colors.HexColor("#888888"),
             leading=10, fontName="Helvetica-Oblique", alignment=TA_CENTER)

# ── Helper Flowables ──────────────────────────────────────────────────────────
class SectionHeader(Flowable):
    def __init__(self, text, bg=NAVY, width=None):
        super().__init__()
        self.text = text
        self.bg = bg
        self._width = width or (A4[0] - 3*cm)
        self.height = 24

    def draw(self):
        c = self.canv
        c.setFillColor(self.bg)
        c.roundRect(0, 0, self._width, self.height, 5, fill=1, stroke=0)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 11)
        c.drawString(10, 7, self.text)

    def wrap(self, *args):
        return self._width, self.height

class ColorBox(Flowable):
    """A coloured banner box with centred text."""
    def __init__(self, text, bg, fg=WHITE, width=None, height=18, radius=4,
                 font="Helvetica-Bold", fontsize=9):
        super().__init__()
        self.text = text
        self.bg = bg
        self.fg = fg
        self._width = width or (A4[0] - 3*cm)
        self._height = height
        self.radius = radius
        self.font = font
        self.fontsize = fontsize

    def draw(self):
        c = self.canv
        c.setFillColor(self.bg)
        c.roundRect(0, 0, self._width, self._height, self.radius, fill=1, stroke=0)
        c.setFillColor(self.fg)
        c.setFont(self.font, self.fontsize)
        c.drawCentredString(self._width / 2, (self._height - self.fontsize) / 2 + 1, self.text)

    def wrap(self, *args):
        return self._width, self._height

def bullet(text, color=STEEL):
    marker = f'<font color="#{hex(int(color.red*255))[2:].zfill(2)}{hex(int(color.green*255))[2:].zfill(2)}{hex(int(color.blue*255))[2:].zfill(2)}">●</font>'
    return Paragraph(f"{marker}  {text}", BULLET)

def sp(h=4):
    return Spacer(1, h)

def hr(color=LIGHT_GRAY, thickness=0.5):
    return HRFlowable(width="100%", thickness=thickness, color=color, spaceAfter=4, spaceBefore=4)

# ── Cover Page ────────────────────────────────────────────────────────────────
class CoverPage(Flowable):
    def __init__(self, w, h):
        super().__init__()
        self._w = w
        self._h = h

    def draw(self):
        c = self.canv
        # Gradient-style background: navy top, steel bottom
        c.setFillColor(NAVY)
        c.rect(0, 0, self._w, self._h, fill=1, stroke=0)
        # Accent strip
        c.setFillColor(STEEL)
        c.rect(0, self._h * 0.38, self._w, self._h * 0.62, fill=1, stroke=0)
        c.setFillColor(NAVY)
        c.rect(0, self._h * 0.42, self._w, self._h * 0.58, fill=1, stroke=0)
        # Bottom accent
        c.setFillColor(TEAL)
        c.rect(0, 0, self._w, 8, fill=1, stroke=0)
        c.setFillColor(ORANGE)
        c.rect(0, 8, self._w, 4, fill=1, stroke=0)

    def wrap(self, *args):
        return self._w, self._h

# ── Build PDF ─────────────────────────────────────────────────────────────────
W, H = A4
MARGIN = 1.5 * cm
doc = SimpleDocTemplate(
    OUTPUT, pagesize=A4,
    leftMargin=MARGIN, rightMargin=MARGIN,
    topMargin=MARGIN, bottomMargin=MARGIN,
    title="Peptic Ulcer Quick Reference Guide",
    author="Medical Quick Reference",
    subject="Peptic Ulcer Diagnosis & Treatment"
)

story = []
CONTENT_W = W - 2 * MARGIN

# ══════════════════════════════════════════════════════════════════════════════
# PAGE 1 — COVER
# ══════════════════════════════════════════════════════════════════════════════
story.append(CoverPage(CONTENT_W, H - 2*MARGIN))

# Overlay text via table on cover
cover_data = [
    [Paragraph("QUICK REFERENCE GUIDE", S("cr1", fontSize=11, textColor=colors.HexColor("#AED6F1"),
               fontName="Helvetica", alignment=TA_CENTER, leading=14))],
    [Spacer(1, 10)],
    [Paragraph("PEPTIC ULCER", S("cr2", fontSize=36, textColor=WHITE,
               fontName="Helvetica-Bold", alignment=TA_CENTER, leading=42))],
    [Paragraph("DISEASE", S("cr3", fontSize=36, textColor=colors.HexColor("#FFD700"),
               fontName="Helvetica-Bold", alignment=TA_CENTER, leading=42))],
    [Spacer(1, 12)],
    [Paragraph("Diagnosis · Pathogenesis · Treatment · Complications", S("cr4",
               fontSize=12, textColor=colors.HexColor("#CFE2FF"),
               fontName="Helvetica-Oblique", alignment=TA_CENTER, leading=16))],
    [Spacer(1, 30)],
    [Paragraph("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━", S("cr5", fontSize=10,
               textColor=TEAL, alignment=TA_CENTER, leading=14))],
    [Spacer(1, 12)],
    [Paragraph("Based on: Harsh Mohan Textbook of Pathology · Robbins &amp; Kumar Basic Pathology<br/>"
               "Bailey &amp; Love's Short Practice of Surgery · Sleisenger &amp; Fordtran's GI Disease",
               S("cr6", fontSize=9, textColor=colors.HexColor("#AED6F1"),
               fontName="Helvetica-Oblique", alignment=TA_CENTER, leading=13))],
    [Spacer(1, 20)],
    [Paragraph("For Educational Use Only  |  May 2026",
               S("cr7", fontSize=9, textColor=colors.HexColor("#7FB3D3"),
               fontName="Helvetica", alignment=TA_CENTER, leading=12))],
]

cover_table = Table(cover_data, colWidths=[CONTENT_W])
cover_table.setStyle(TableStyle([
    ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
    ("TOPPADDING", (0,0), (-1,-1), 2),
    ("BOTTOMPADDING", (0,0), (-1,-1), 2),
]))

# Place the cover text over the cover background using a frame trick
# We wrap cover bg + text as a composite table
final_cover = Table(
    [[cover_table]],
    colWidths=[CONTENT_W],
    rowHeights=[H - 2*MARGIN]
)
final_cover.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,-1), NAVY),
    ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
    ("ALIGN", (0,0), (-1,-1), "CENTER"),
    ("ROUNDEDCORNERS", [8]),
    ("TOPPADDING", (0,0), (-1,-1), 60),
    ("BOTTOMPADDING", (0,0), (-1,-1), 40),
]))
story.append(final_cover)
story.append(Spacer(1, 10))

# ══════════════════════════════════════════════════════════════════════════════
# PAGE 2 — OVERVIEW + CLASSIFICATION + ACUTE ULCERS
# ══════════════════════════════════════════════════════════════════════════════

# ── Section 1: Overview ──────────────────────────────────────────────────────
story.append(SectionHeader("1  OVERVIEW — PEPTIC ULCERS", bg=NAVY))
story.append(sp(6))

overview_cols = [
    # Left column
    [
        Paragraph("<b>Definition</b>", SUBSEC),
        bullet("Areas of degeneration &amp; necrosis of GI mucosa"),
        bullet("Exposed to acid-pepsin secretions"),
        bullet("<b>Acid is essential</b> — no acid = no ulcer"),
        bullet("PPIs render patient achlorhydric → heal ulcers"),
        sp(6),
        Paragraph("<b>Common Sites</b>", SUBSEC),
        bullet("1st part of duodenum <b>(most common)</b>"),
        bullet("Stomach — lesser curvature &amp; antrum"),
        bullet("Lower oesophagus (GERD-related)"),
        bullet("Meckel's diverticulum (ectopic gastric mucosa)"),
        sp(6),
        Paragraph("<b>Duodenum : Stomach Ratio = 4 : 1</b>", 
                  S("ratio", fontSize=10, textColor=STEEL, fontName="Helvetica-Bold",
                    leading=14, leftIndent=8)),
    ],
    # Right column — classification box
    [
        Paragraph("<b>Classification</b>", SUBSEC),
        sp(4),
        Table([
            [Paragraph("PEPTIC ULCERS", S("ct", fontSize=10, textColor=WHITE,
                        fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13))],
        ], colWidths=[7.5*cm], style=TableStyle([
            ("BACKGROUND", (0,0), (-1,-1), NAVY),
            ("ROUNDEDCORNERS", [6]),
            ("TOPPADDING", (0,0), (-1,-1), 6),
            ("BOTTOMPADDING", (0,0), (-1,-1), 6),
        ])),
        sp(4),
        Table([
            [
                Table([[Paragraph("TYPE 1\nACUTE\n(Stress) Ulcers", S("bt1",
                         fontSize=9, textColor=WHITE, fontName="Helvetica-Bold",
                         alignment=TA_CENTER, leading=13))]],
                      colWidths=[3.4*cm],
                      style=TableStyle([
                          ("BACKGROUND",(0,0),(-1,-1), ORANGE),
                          ("ROUNDEDCORNERS",[6]),
                          ("TOPPADDING",(0,0),(-1,-1),10),
                          ("BOTTOMPADDING",(0,0),(-1,-1),10),
                      ])),
                Table([[Paragraph("TYPE 2\nCHRONIC\nPeptic Ulcers", S("bt2",
                         fontSize=9, textColor=WHITE, fontName="Helvetica-Bold",
                         alignment=TA_CENTER, leading=13))]],
                      colWidths=[3.4*cm],
                      style=TableStyle([
                          ("BACKGROUND",(0,0),(-1,-1), STEEL),
                          ("ROUNDEDCORNERS",[6]),
                          ("TOPPADDING",(0,0),(-1,-1),10),
                          ("BOTTOMPADDING",(0,0),(-1,-1),10),
                      ])),
            ]
        ], colWidths=[3.6*cm, 3.6*cm], style=TableStyle([
            ("ALIGN",(0,0),(-1,-1),"CENTER"),
            ("LEFTPADDING",(0,0),(-1,-1),3),
            ("RIGHTPADDING",(0,0),(-1,-1),3),
        ])),
        sp(6),
        Table([
            [
                Table([[Paragraph("GASTRIC\nULCER", S("bt3", fontSize=9, textColor=WHITE,
                         fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13))]],
                      colWidths=[3.4*cm],
                      style=TableStyle([
                          ("BACKGROUND",(0,0),(-1,-1), TEAL),
                          ("ROUNDEDCORNERS",[6]),
                          ("TOPPADDING",(0,0),(-1,-1),8),
                          ("BOTTOMPADDING",(0,0),(-1,-1),8),
                      ])),
                Table([[Paragraph("DUODENAL\nULCER", S("bt4", fontSize=9, textColor=WHITE,
                         fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13))]],
                      colWidths=[3.4*cm],
                      style=TableStyle([
                          ("BACKGROUND",(0,0),(-1,-1), PURPLE),
                          ("ROUNDEDCORNERS",[6]),
                          ("TOPPADDING",(0,0),(-1,-1),8),
                          ("BOTTOMPADDING",(0,0),(-1,-1),8),
                      ])),
            ]
        ], colWidths=[3.6*cm, 3.6*cm], style=TableStyle([
            ("ALIGN",(0,0),(-1,-1),"CENTER"),
            ("LEFTPADDING",(0,0),(-1,-1),3),
            ("RIGHTPADDING",(0,0),(-1,-1),3),
        ])),
    ]
]

overview_table = Table(
    [[overview_cols[0], overview_cols[1]]],
    colWidths=[CONTENT_W*0.50, CONTENT_W*0.50],
    style=TableStyle([
        ("VALIGN", (0,0), (-1,-1), "TOP"),
        ("LEFTPADDING", (0,0), (-1,-1), 4),
        ("RIGHTPADDING", (0,0), (-1,-1), 4),
    ])
)
story.append(overview_table)
story.append(sp(10))

# ── Section 2: Acute Stress Ulcers ───────────────────────────────────────────
story.append(SectionHeader("2  ACUTE (STRESS) ULCERS", bg=ORANGE))
story.append(sp(6))

acute_left = [
    Paragraph("<b>Etiology</b>", SUBSEC),
    bullet("Psychological stress"),
    bullet("Shock (hypovolemic / septic)"),
    bullet("Severe trauma"),
    bullet("Septicaemia"),
    bullet("<b>Burns</b> → <b>Curling's ulcers</b> (posterior duodenum)"),
    bullet("<b>Brain injury / tumours</b> → <b>Cushing's ulcers</b><br/>"
           "<i>(intracranial → ↑ vagal stimulation → hyperacidity)</i>"),
    bullet("Drugs: Aspirin, steroids, indomethacin"),
    bullet("Local irritants: alcohol, smoking, coffee"),
    sp(6),
    Paragraph("<b>Pathogenesis</b>", SUBSEC),
    bullet("Ischaemic hypoxic injury to mucosal cells"),
    bullet("Depletion of gastric mucus barrier"),
    bullet("→ Acid-pepsin attacks unprotected mucosa"),
]

acute_right = [
    Paragraph("<b>Morphology</b>", SUBSEC),
    Paragraph("<b>Gross:</b>", S("gh", fontSize=9, textColor=STEEL, fontName="Helvetica-Bold", leading=13)),
    bullet("Multiple (&gt;3 ulcers in 75% of cases)"),
    bullet("Distribution: Stomach &gt; Duodenum (1st part)"),
    bullet("Oval/circular, <b>&lt; 1 cm</b> diameter"),
    sp(4),
    Paragraph("<b>Microscopic:</b>", S("mh", fontSize=9, textColor=STEEL, fontName="Helvetica-Bold", leading=13)),
    bullet("Shallow — do NOT invade muscularis"),
    bullet("Base shows mild inflammatory reaction"),
    bullet("Heal by <b>complete re-epithelialisation</b>"),
    bullet("<b>No scar formation</b>"),
    sp(6),
    Paragraph("<b>Complications</b>", SUBSEC),
    Table([
        [Paragraph("⚠ Haemorrhage", S("comp1", fontSize=9, textColor=WHITE,
                   fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13)),
         Paragraph("⚠ Perforation", S("comp2", fontSize=9, textColor=WHITE,
                   fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13))]
    ], colWidths=[CONTENT_W*0.22, CONTENT_W*0.22],
       style=TableStyle([
           ("BACKGROUND", (0,0), (0,0), RED),
           ("BACKGROUND", (1,0), (1,0), ORANGE),
           ("ROUNDEDCORNERS", [5]),
           ("TOPPADDING",(0,0),(-1,-1),6),
           ("BOTTOMPADDING",(0,0),(-1,-1),6),
       ]))
]

acute_table = Table(
    [[acute_left, acute_right]],
    colWidths=[CONTENT_W*0.50, CONTENT_W*0.50],
    style=TableStyle([
        ("VALIGN", (0,0), (-1,-1), "TOP"),
        ("LEFTPADDING", (0,0), (-1,-1), 4),
        ("RIGHTPADDING", (0,0), (-1,-1), 4),
        ("BACKGROUND", (0,0), (0,0), YELLOW_BG),
        ("BACKGROUND", (1,0), (1,0), colors.HexColor("#FFF3E0")),
        ("ROUNDEDCORNERS", [6]),
        ("TOPPADDING",(0,0),(-1,-1),8),
        ("BOTTOMPADDING",(0,0),(-1,-1),8),
    ])
)
story.append(acute_table)
story.append(sp(10))

# ── Section 3: Pathogenesis of Chronic PUD ───────────────────────────────────
story.append(SectionHeader("3  CHRONIC PEPTIC ULCER — PATHOGENESIS", bg=STEEL))
story.append(sp(8))

# Flowchart as a table
fc_style = lambda bg, fg=WHITE: TableStyle([
    ("BACKGROUND",(0,0),(-1,-1), bg),
    ("ROUNDEDCORNERS",[8]),
    ("TOPPADDING",(0,0),(-1,-1),7),
    ("BOTTOMPADDING",(0,0),(-1,-1),7),
    ("LEFTPADDING",(0,0),(-1,-1),8),
    ("RIGHTPADDING",(0,0),(-1,-1),8),
    ("ALIGN",(0,0),(-1,-1),"CENTER"),
])

arrow_p = Paragraph("▼", S("arr", fontSize=14, textColor=STEEL,
                            fontName="Helvetica-Bold", alignment=TA_CENTER, leading=16))

def fc_box(text, bg, fg=WHITE, width=CONTENT_W*0.6):
    return Table([[Paragraph(text, S("fc"+text[:5], fontSize=9, textColor=fg,
                  fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13))]],
                 colWidths=[width], style=fc_style(bg))

def fc_row(box):
    return [Spacer(CONTENT_W*0.2, 1), box]

flow_data = [
    [Spacer(1,2), fc_box("H. pylori  ·  NSAIDs  ·  Stress  ·  Hyperacidity  ·  Gastritis",
                          NAVY, width=CONTENT_W*0.85)],
    [Spacer(1,2), arrow_p],
    [Spacer(1,2), fc_box("DISRUPTION OF MUCOSAL BARRIER\n(↓ mucus  ·  ↓ bicarbonate  ·  ↓ mucosal blood flow)",
                          STEEL, width=CONTENT_W*0.85)],
    [Spacer(1,2), arrow_p],
    [Spacer(1,2), fc_box("ACID-PEPSIN ATTACKS UNPROTECTED MUCOSA",
                          ORANGE, width=CONTENT_W*0.85)],
    [Spacer(1,2), arrow_p],
    [Spacer(1,2), fc_box("MUCOSAL EROSION  →  ULCERATION",
                          RED, width=CONTENT_W*0.85)],
    [Spacer(1,2), arrow_p],
]
center_fc = Table(flow_data, colWidths=[CONTENT_W*0.07, CONTENT_W*0.93],
                  style=TableStyle([
                      ("VALIGN",(0,0),(-1,-1),"MIDDLE"),
                      ("ALIGN",(0,0),(-1,-1),"CENTER"),
                      ("TOPPADDING",(0,0),(-1,-1),1),
                      ("BOTTOMPADDING",(0,0),(-1,-1),1),
                  ]))
story.append(center_fc)

# Branch boxes
branch_data = [[
    Table([[Paragraph("GASTRIC ULCER\n\n• Normal / Low acid\n• Mucosal barrier\n  damage is KEY",
                      S("gb", fontSize=9, textColor=WHITE, fontName="Helvetica",
                        alignment=TA_CENTER, leading=13))]],
          colWidths=[CONTENT_W*0.38],
          style=TableStyle([
              ("BACKGROUND",(0,0),(-1,-1), TEAL),
              ("ROUNDEDCORNERS",[8]),
              ("TOPPADDING",(0,0),(-1,-1),10),
              ("BOTTOMPADDING",(0,0),(-1,-1),10),
          ])),
    Spacer(CONTENT_W*0.08, 1),
    Table([[Paragraph("DUODENAL ULCER\n\n• HIGH acid levels\n• H. pylori is\n  primary driver",
                      S("db", fontSize=9, textColor=WHITE, fontName="Helvetica",
                        alignment=TA_CENTER, leading=13))]],
          colWidths=[CONTENT_W*0.38],
          style=TableStyle([
              ("BACKGROUND",(0,0),(-1,-1), PURPLE),
              ("ROUNDEDCORNERS",[8]),
              ("TOPPADDING",(0,0),(-1,-1),10),
              ("BOTTOMPADDING",(0,0),(-1,-1),10),
          ])),
]]
branch_table = Table(branch_data, colWidths=[CONTENT_W*0.44, CONTENT_W*0.08, CONTENT_W*0.44],
                     style=TableStyle([
                         ("ALIGN",(0,0),(-1,-1),"CENTER"),
                         ("VALIGN",(0,0),(-1,-1),"MIDDLE"),
                     ]))
story.append(branch_table)
story.append(sp(10))

# 4 factors in 2x2 grid
story.append(Paragraph("<b>4 Key Pathogenic Factors</b>", SUBSEC))
story.append(sp(6))

factor_data = [
    [
        Table([[
            Paragraph("<b>1. H. pylori Infection 🦠</b>", S("f1h", fontSize=9, textColor=WHITE,
                       fontName="Helvetica-Bold", leading=13)),
            Spacer(1,4),
            Paragraph("• 70–80% of PUD associated with H. pylori\n"
                       "• H. pylori in antrum → duodenal ulcer\n"
                       "• Gastric colonisation = asymptomatic\n"
                       "• Only 5–10% of infected → ulcers\n"
                       "• Identified by histology/culture/serology",
                       S("f1b", fontSize=8.5, textColor=WHITE, fontName="Helvetica", leading=13)),
        ]], colWidths=[CONTENT_W*0.46],
        style=TableStyle([
            ("BACKGROUND",(0,0),(-1,-1), STEEL),
            ("ROUNDEDCORNERS",[8]),
            ("TOPPADDING",(0,0),(-1,-1),10),
            ("BOTTOMPADDING",(0,0),(-1,-1),10),
            ("LEFTPADDING",(0,0),(-1,-1),10),
            ("RIGHTPADDING",(0,0),(-1,-1),10),
        ])),

        Table([[
            Paragraph("<b>2. NSAIDs-Induced Injury 💊</b>", S("f2h", fontSize=9, textColor=WHITE,
                       fontName="Helvetica-Bold", leading=13)),
            Spacer(1,4),
            Paragraph("• Most common drug class causing PUD\n"
                       "• Inhibit COX → ↓ prostaglandins\n"
                       "• ↓ Mucus &amp; bicarbonate secretion\n"
                       "• Damage endothelial cells + epithelium\n"
                       "• Risk ↑ with low-dose aspirin in elderly",
                       S("f2b", fontSize=8.5, textColor=WHITE, fontName="Helvetica", leading=13)),
        ]], colWidths=[CONTENT_W*0.46],
        style=TableStyle([
            ("BACKGROUND",(0,0),(-1,-1), ORANGE),
            ("ROUNDEDCORNERS",[8]),
            ("TOPPADDING",(0,0),(-1,-1),10),
            ("BOTTOMPADDING",(0,0),(-1,-1),10),
            ("LEFTPADDING",(0,0),(-1,-1),10),
            ("RIGHTPADDING",(0,0),(-1,-1),10),
        ])),
    ],
    [Spacer(1,8), Spacer(1,8)],
    [
        Table([[
            Paragraph("<b>3. Acid-Pepsin Secretions 🧪</b>", S("f3h", fontSize=9, textColor=WHITE,
                       fontName="Helvetica-Bold", leading=13)),
            Spacer(1,4),
            Paragraph("• Essential for ulcer formation\n"
                       "• PU never occurs in pernicious anaemia\n"
                       "  (no acid / pepsin-secreting cells)\n"
                       "• Zollinger-Ellison: gastrinoma → massive\n"
                       "  acid → ulcers in stomach + duodenum +\n"
                       "  jejunum",
                       S("f3b", fontSize=8.5, textColor=WHITE, fontName="Helvetica", leading=13)),
        ]], colWidths=[CONTENT_W*0.46],
        style=TableStyle([
            ("BACKGROUND",(0,0),(-1,-1), TEAL),
            ("ROUNDEDCORNERS",[8]),
            ("TOPPADDING",(0,0),(-1,-1),10),
            ("BOTTOMPADDING",(0,0),(-1,-1),10),
            ("LEFTPADDING",(0,0),(-1,-1),10),
            ("RIGHTPADDING",(0,0),(-1,-1),10),
        ])),

        Table([[
            Paragraph("<b>4. Gastritis (Background) 🔥</b>", S("f4h", fontSize=9, textColor=WHITE,
                       fontName="Helvetica-Bold", leading=13)),
            Spacer(1,4),
            Paragraph("• Gastritis ALWAYS present near gastric\n"
                       "  ulcer region\n"
                       "• Gastric ulcer distribution mirrors\n"
                       "  chronic gastritis distribution\n"
                       "• Other cofactors: smoking, alcohol,\n"
                       "  cirrhosis, renal failure, hyperPTH",
                       S("f4b", fontSize=8.5, textColor=WHITE, fontName="Helvetica", leading=13)),
        ]], colWidths=[CONTENT_W*0.46],
        style=TableStyle([
            ("BACKGROUND",(0,0),(-1,-1), PURPLE),
            ("ROUNDEDCORNERS",[8]),
            ("TOPPADDING",(0,0),(-1,-1),10),
            ("BOTTOMPADDING",(0,0),(-1,-1),10),
            ("LEFTPADDING",(0,0),(-1,-1),10),
            ("RIGHTPADDING",(0,0),(-1,-1),10),
        ])),
    ],
]
factor_table = Table(factor_data,
                     colWidths=[CONTENT_W*0.49, CONTENT_W*0.49],
                     style=TableStyle([
                         ("VALIGN",(0,0),(-1,-1),"TOP"),
                         ("LEFTPADDING",(0,0),(-1,-1),3),
                         ("RIGHTPADDING",(0,0),(-1,-1),3),
                     ]))
story.append(factor_table)
story.append(sp(10))

# ── Section 4: Comparison Table ───────────────────────────────────────────────
story.append(SectionHeader("4  GASTRIC vs DUODENAL ULCER — COMPARISON", bg=TEAL))
story.append(sp(8))

hdr = lambda t: Paragraph(t, TBL_HEAD)
cel = lambda t: Paragraph(t, TBL_CELL)
celc= lambda t: Paragraph(t, TBL_CELL_C)

comp_data = [
    [hdr("Feature"), hdr("Duodenal Ulcer"), hdr("Gastric Ulcer")],
    [cel("Incidence"), cel("4× MORE COMMON"), cel("Less common")],
    [cel("Age"), cel("25–50 yrs (5th decade)"), cel("> 60 yrs (6th decade)")],
    [cel("Sex (M:F)"), cel("4 : 1"), cel("3.5 : 1")],
    [cel("Main Cause"), cel("H. pylori + Hyperacidity"), cel("Mucosal barrier damage")],
    [cel("Acid Level"), cel("HIGH ↑"), cel("Normal or LOW ↓")],
    [cel("Site"), cel("1st part of duodenum"), cel("Lesser curvature + antrum")],
    [cel("Appearance"), cel("Solitary, punched-out,\n1–2.5 cm, round/oval"), cel("Grossly similar")],
    [cel("Histology"), cel("4 layers:\nNecrotic → Exudative\n→ Granulation → Scar"),
                       cel("Indistinguishable from\nduodenal ulcer")],
    [cel("Malignant risk"), cel("Very RARE"), cel("⚠ YES — always biopsy!")],
    [cel("Complications"), cel("Haemorrhage, Perforation,\nStenosis"), cel("Perforation, Haemorrhage,\nObstruction")],
]

comp_table = Table(comp_data,
                   colWidths=[CONTENT_W*0.26, CONTENT_W*0.37, CONTENT_W*0.37],
                   repeatRows=1)
comp_table.setStyle(TableStyle([
    # Header row
    ("BACKGROUND", (0,0), (-1,0), TEAL),
    ("TEXTCOLOR", (0,0), (-1,0), WHITE),
    ("FONTNAME", (0,0), (-1,0), "Helvetica-Bold"),
    ("FONTSIZE", (0,0), (-1,0), 9),
    ("ALIGN", (0,0), (-1,0), "CENTER"),
    # Feature column
    ("BACKGROUND", (0,1), (0,-1), colors.HexColor("#E0F2F1")),
    ("FONTNAME", (0,1), (0,-1), "Helvetica-Bold"),
    ("FONTSIZE", (0,1), (0,-1), 8.5),
    # Alternating rows
    ("BACKGROUND", (1,1), (-1,1), WHITE),
    ("BACKGROUND", (1,2), (-1,2), LIGHT_GRAY),
    ("BACKGROUND", (1,3), (-1,3), WHITE),
    ("BACKGROUND", (1,4), (-1,4), LIGHT_GRAY),
    ("BACKGROUND", (1,5), (-1,5), WHITE),
    ("BACKGROUND", (1,6), (-1,6), LIGHT_GRAY),
    ("BACKGROUND", (1,7), (-1,7), WHITE),
    ("BACKGROUND", (1,8), (-1,8), LIGHT_GRAY),
    ("BACKGROUND", (1,9), (-1,9), RED_BG),
    ("BACKGROUND", (0,9), (0,9), RED_BG),
    ("BACKGROUND", (1,10), (-1,10), WHITE),
    # Grid
    ("GRID", (0,0), (-1,-1), 0.5, colors.HexColor("#B0BEC5")),
    ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
    ("TOPPADDING", (0,0), (-1,-1), 5),
    ("BOTTOMPADDING", (0,0), (-1,-1), 5),
    ("LEFTPADDING", (0,0), (-1,-1), 6),
    ("RIGHTPADDING", (0,0), (-1,-1), 6),
    ("ROWBACKGROUNDS", (0,0), (-1,-1), [None]),
]))
story.append(comp_table)
story.append(sp(10))

# ── Section 5: Incidence + Diagnosis ─────────────────────────────────────────
story.append(SectionHeader("5  CLINICAL FEATURES & DIAGNOSIS", bg=PURPLE))
story.append(sp(6))

diag_left = [
    Paragraph("<b>Symptoms</b>", SUBSEC),
    bullet("Epigastric pain / burning (most common)"),
    bullet("Duodenal ulcer: pain <b>relieved</b> by food/antacids"),
    bullet("Gastric ulcer: pain <b>worsened</b> by food"),
    bullet("Nausea, vomiting, bloating"),
    bullet("Weight loss (esp. gastric ulcer)"),
    bullet("Haematemesis or melaena (bleeding)"),
    sp(6),
    Paragraph("<b>Signs</b>", SUBSEC),
    bullet("Epigastric tenderness"),
    bullet("Succussion splash (pyloric stenosis)"),
    bullet("Peritonism (perforation)"),
    bullet("Anaemia (chronic blood loss)"),
]

diag_right = [
    Paragraph("<b>Investigations</b>", SUBSEC),
    Table([
        [Paragraph("TEST", TBL_HEAD), Paragraph("PURPOSE", TBL_HEAD)],
        [cel("OGD (endoscopy)"), cel("Gold standard — visualise + biopsy")],
        [cel("Biopsy (CLO test)"), cel("H. pylori detection + exclude malignancy")],
        [cel("Urea breath test"), cel("Non-invasive H. pylori test")],
        [cel("Stool antigen test"), cel("H. pylori — test of cure")],
        [cel("Serology (IgG)"), cel("H. pylori (less specific)")],
        [cel("Barium meal"), cel("If endoscopy unavailable")],
        [cel("FBC / Iron studies"), cel("Assess anaemia from blood loss")],
        [cel("AXR / CXR erect"), cel("Free air under diaphragm (perforation)")],
    ], colWidths=[CONTENT_W*0.25, CONTENT_W*0.23],
       style=TableStyle([
           ("BACKGROUND",(0,0),(-1,0), PURPLE),
           ("TEXTCOLOR",(0,0),(-1,0), WHITE),
           ("FONTNAME",(0,0),(-1,0),"Helvetica-Bold"),
           ("FONTSIZE",(0,0),(-1,-1),8),
           ("GRID",(0,0),(-1,-1),0.4, colors.HexColor("#C0C0C0")),
           ("ROWBACKGROUNDS",(0,1),(-1,-1),[WHITE, LIGHT_GRAY]),
           ("VALIGN",(0,0),(-1,-1),"MIDDLE"),
           ("TOPPADDING",(0,0),(-1,-1),4),
           ("BOTTOMPADDING",(0,0),(-1,-1),4),
           ("LEFTPADDING",(0,0),(-1,-1),5),
           ("RIGHTPADDING",(0,0),(-1,-1),5),
       ])),
]

diag_table = Table(
    [[diag_left, diag_right]],
    colWidths=[CONTENT_W*0.40, CONTENT_W*0.60],
    style=TableStyle([
        ("VALIGN",(0,0),(-1,-1),"TOP"),
        ("LEFTPADDING",(0,0),(-1,-1),4),
        ("RIGHTPADDING",(0,0),(-1,-1),4),
    ])
)
story.append(diag_table)
story.append(sp(10))

# ── Section 6: Treatment ──────────────────────────────────────────────────────
story.append(SectionHeader("6  TREATMENT", bg=GREEN))
story.append(sp(6))

# Step-by-step treatment flowchart
steps = [
    ("STEP 1", "Acid Suppression", "PPI (Omeprazole 20–40 mg BD or Pantoprazole 40 mg OD)\n→ Renders patient achlorhydric → heals mucosa", GREEN),
    ("STEP 2", "H. pylori Eradication", "Triple Therapy × 14 days:\nPPI + Clarithromycin 500 mg + Amoxicillin 1 g  (all BD)\nIf penicillin allergy: replace amoxicillin with Metronidazole 400 mg", STEEL),
    ("STEP 3", "Lifestyle Modification", "Stop NSAIDs · Stop smoking · Avoid alcohol\nReduce stress · Small frequent meals", TEAL),
    ("STEP 4", "Test for Eradication", "Urea breath test or stool antigen test\n≥ 4 weeks after completing therapy (off PPIs × 2 weeks)", ORANGE),
    ("STEP 5", "Surgery (Complications)", "Perforation → Laparotomy + repair\nBleeding → Endoscopic haemostasis → surgery if refractory\nObstruction → Balloon dilatation / gastrojejunostomy", RED),
]

for step, title, detail, col in steps:
    step_data = [[
        Table([[Paragraph(step, S("st_badge", fontSize=9, textColor=WHITE,
                            fontName="Helvetica-Bold", alignment=TA_CENTER, leading=13))]],
              colWidths=[1.5*cm],
              style=TableStyle([
                  ("BACKGROUND",(0,0),(-1,-1), col),
                  ("ROUNDEDCORNERS",[5]),
                  ("TOPPADDING",(0,0),(-1,-1),10),
                  ("BOTTOMPADDING",(0,0),(-1,-1),10),
              ])),
        Table([[
            Paragraph(f"<b>{title}</b>", S("st_t", fontSize=9.5, textColor=col,
                       fontName="Helvetica-Bold", leading=13)),
            Paragraph(detail, S("st_d", fontSize=8.5, textColor=BLACK,
                       fontName="Helvetica", leading=13)),
        ]], colWidths=[CONTENT_W - 2.2*cm],
        style=TableStyle([
            ("BACKGROUND",(0,0),(-1,-1), GRAY_BG),
            ("TOPPADDING",(0,0),(-1,-1),6),
            ("BOTTOMPADDING",(0,0),(-1,-1),6),
            ("LEFTPADDING",(0,0),(-1,-1),8),
            ("RIGHTPADDING",(0,0),(-1,-1),8),
        ])),
    ]]
    story.append(Table(step_data, colWidths=[1.8*cm, CONTENT_W - 1.8*cm],
                       style=TableStyle([
                           ("VALIGN",(0,0),(-1,-1),"MIDDLE"),
                           ("LEFTPADDING",(0,0),(-1,-1),2),
                           ("RIGHTPADDING",(0,0),(-1,-1),2),
                       ])))
    story.append(sp(4))

story.append(sp(6))

# ── Section 7: Complications ──────────────────────────────────────────────────
story.append(SectionHeader("7  COMPLICATIONS", bg=RED))
story.append(sp(6))

comp_boxes = [
    ("Haemorrhage\n(Most Common)", "Haematemesis / melaena\nEndoscopic haemostasis\nSurgery if refractory", RED),
    ("Perforation", "Gastric > Duodenal\nPeritonitis\nSurgical emergency\nFree air on CXR", ORANGE),
    ("Obstruction /\nStenosis", "Duodenal ulcer → pyloric stenosis\nVomiting + weight loss\nBalloon dilatation", TEAL),
    ("Penetration", "Ulcer into pancreas,\nliver, biliary tree\nPain radiates to back", STEEL),
    ("Malignancy", "GASTRIC ULCER ONLY\n(Duodenal = very rare)\nMUST biopsy all\ngastric ulcers", PURPLE),
]

comp_row = []
for title, detail, col in comp_boxes:
    comp_row.append(
        Table([[
            Paragraph(title, S("cbt", fontSize=8.5, textColor=WHITE, fontName="Helvetica-Bold",
                       alignment=TA_CENTER, leading=13)),
            Spacer(1,4),
            Paragraph(detail, S("cbd", fontSize=7.5, textColor=WHITE, fontName="Helvetica",
                       alignment=TA_CENTER, leading=12)),
        ]], colWidths=[CONTENT_W/5 - 4],
        style=TableStyle([
            ("BACKGROUND",(0,0),(-1,-1), col),
            ("ROUNDEDCORNERS",[8]),
            ("TOPPADDING",(0,0),(-1,-1),8),
            ("BOTTOMPADDING",(0,0),(-1,-1),8),
            ("LEFTPADDING",(0,0),(-1,-1),5),
            ("RIGHTPADDING",(0,0),(-1,-1),5),
        ]))
    )

complications_table = Table(
    [comp_row],
    colWidths=[CONTENT_W/5]*5,
    style=TableStyle([
        ("VALIGN",(0,0),(-1,-1),"TOP"),
        ("LEFTPADDING",(0,0),(-1,-1),3),
        ("RIGHTPADDING",(0,0),(-1,-1),3),
    ])
)
story.append(complications_table)
story.append(sp(10))

# ── Section 8: High-Yield Summary ─────────────────────────────────────────────
story.append(SectionHeader("8  HIGH-YIELD EXAM POINTS", bg=colors.HexColor("#37474F")))
story.append(sp(6))

hye_data = [
    ["No acid = No ulcer", "PPIs cure by rendering patient achlorhydric"],
    ["Most common cause", "H. pylori (70–80% of PUD)"],
    ["D : G ulcer ratio", "Duodenal : Gastric = 4 : 1"],
    ["Curling's ulcer", "Burns → posterior duodenum"],
    ["Cushing's ulcer", "Brain injury → vagal stim → hyperacidity"],
    ["Pernicious anaemia", "NEVER get peptic ulcers (no acid/pepsin)"],
    ["Zollinger-Ellison", "Gastrinoma → massive acid → ulcers in stomach + duodenum + jejunum"],
    ["Always biopsy", "Gastric ulcer (rule out malignancy — never skip!)"],
    ["Duodenal histology", "4 layers: Necrotic → Exudative → Granulation → Scar"],
    ["Duodenal pain", "RELIEVED by food/antacids (food buffers acid)"],
    ["Gastric pain", "WORSENED by food (food stimulates acid)"],
    ["Test of cure", "Urea breath test ≥ 4 weeks after triple therapy"],
]

hye_table = Table(
    [[Paragraph(f"<b>{row[0]}</b>", S("hyek", fontSize=8.5, textColor=NAVY,
                fontName="Helvetica-Bold", leading=13)),
      Paragraph(f"→  {row[1]}", S("hyev", fontSize=8.5, textColor=BLACK,
                fontName="Helvetica", leading=13))]
     for row in hye_data],
    colWidths=[CONTENT_W*0.34, CONTENT_W*0.66],
    style=TableStyle([
        ("ROWBACKGROUNDS", (0,0), (-1,-1), [WHITE, LIGHT_GRAY]),
        ("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#CFD8DC")),
        ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
        ("TOPPADDING", (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 5),
        ("LEFTPADDING", (0,0), (-1,-1), 8),
        ("RIGHTPADDING", (0,0), (-1,-1), 8),
        ("BACKGROUND", (0,0), (0,-1), colors.HexColor("#E3F2FD")),
        ("FONTNAME", (0,0), (0,-1), "Helvetica-Bold"),
    ])
)
story.append(hye_table)
story.append(sp(10))

# ── Footer ─────────────────────────────────────────────────────────────────────
story.append(hr(LIGHT_GRAY, 1))
story.append(Paragraph(
    "Sources: Harsh Mohan Textbook of Pathology pp.533–534  ·  Robbins &amp; Kumar Basic Pathology  ·  "
    "Bailey &amp; Love's Short Practice of Surgery 28th Ed.  ·  Sleisenger &amp; Fordtran's GI Disease  |  "
    "For Educational Use Only  |  May 2026",
    FOOTER
))

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