🌾 Chapter 25: Agricultural Poisons (FMT - Narayan Reddy, 36th Ed.) Pages 395-401

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

OUTPUT = "/tmp/workspace/fmt-agricultural-poisons/Agricultural_Poisons_FMT_NarayanReddy.pdf"

# ── colours ──────────────────────────────────────────────────────────────────
C_DARK_BLUE   = colors.HexColor("#1a237e")
C_RED         = colors.HexColor("#b71c1c")
C_AMBER       = colors.HexColor("#e65100")
C_GREEN       = colors.HexColor("#1b5e20")
C_TEAL        = colors.HexColor("#006064")
C_PURPLE      = colors.HexColor("#4a148c")
C_LIGHT_BLUE  = colors.HexColor("#e3f2fd")
C_LIGHT_RED   = colors.HexColor("#ffebee")
C_LIGHT_GREEN = colors.HexColor("#e8f5e9")
C_LIGHT_AMB   = colors.HexColor("#fff3e0")
C_LIGHT_PURP  = colors.HexColor("#f3e5f5")
C_LIGHT_TEAL  = colors.HexColor("#e0f7fa")
C_YELLOW_HL   = colors.HexColor("#fff9c4")
C_GREY_BG     = colors.HexColor("#f5f5f5")
C_DARK_GREY   = colors.HexColor("#424242")
C_MED_GREY    = colors.HexColor("#757575")
C_WHITE       = colors.white
C_BLACK       = colors.black

# ── styles ────────────────────────────────────────────────────────────────────
def build_styles():
    base = getSampleStyleSheet()

    def s(name, parent="Normal", **kw):
        return ParagraphStyle(name, parent=base[parent], **kw)

    return {
        "cover_title": s("cover_title", "Title",
            fontSize=26, textColor=C_DARK_BLUE, spaceAfter=6,
            alignment=TA_CENTER, fontName="Helvetica-Bold"),
        "cover_sub": s("cover_sub",
            fontSize=14, textColor=C_DARK_GREY, spaceAfter=4,
            alignment=TA_CENTER, fontName="Helvetica"),
        "cover_meta": s("cover_meta",
            fontSize=10, textColor=C_MED_GREY, spaceAfter=2,
            alignment=TA_CENTER, fontName="Helvetica-Oblique"),

        "chapter_head": s("chapter_head",
            fontSize=18, textColor=C_WHITE, spaceAfter=2,
            fontName="Helvetica-Bold", alignment=TA_CENTER,
            backColor=C_DARK_BLUE, borderPadding=(8,10,8,10)),

        "part_head": s("part_head",
            fontSize=15, textColor=C_WHITE, spaceAfter=4, spaceBefore=14,
            fontName="Helvetica-Bold", alignment=TA_LEFT,
            backColor=C_RED, borderPadding=(6,8,6,8)),

        "section_head": s("section_head",
            fontSize=13, textColor=C_DARK_BLUE, spaceAfter=4, spaceBefore=10,
            fontName="Helvetica-Bold"),

        "sub_head": s("sub_head",
            fontSize=11, textColor=C_AMBER, spaceAfter=3, spaceBefore=6,
            fontName="Helvetica-Bold"),

        "body": s("body",
            fontSize=10, textColor=C_DARK_GREY, spaceAfter=4,
            leading=15, alignment=TA_JUSTIFY, fontName="Helvetica"),

        "body_bold": s("body_bold",
            fontSize=10, textColor=C_DARK_GREY, spaceAfter=4,
            leading=15, fontName="Helvetica-Bold"),

        "bullet": s("bullet",
            fontSize=10, textColor=C_DARK_GREY, spaceAfter=3,
            leading=14, leftIndent=16, fontName="Helvetica",
            bulletText="•"),

        "trick_box": s("trick_box",
            fontSize=10, textColor=C_GREEN, spaceAfter=4,
            leading=14, fontName="Helvetica-Bold",
            backColor=C_LIGHT_GREEN, borderPadding=(6,8,6,8)),

        "warning_box": s("warning_box",
            fontSize=10, textColor=C_RED, spaceAfter=4,
            leading=14, fontName="Helvetica-Bold",
            backColor=C_LIGHT_RED, borderPadding=(6,8,6,8)),

        "highlight": s("highlight",
            fontSize=10, textColor=C_DARK_GREY, spaceAfter=4,
            leading=14, fontName="Helvetica",
            backColor=C_YELLOW_HL, borderPadding=(5,8,5,8)),

        "code_box": s("code_box",
            fontSize=9, textColor=C_DARK_GREY, spaceAfter=4,
            leading=13, fontName="Courier",
            backColor=C_GREY_BG, borderPadding=(6,8,6,8)),

        "q_head": s("q_head",
            fontSize=13, textColor=C_WHITE, spaceAfter=4, spaceBefore=10,
            fontName="Helvetica-Bold", alignment=TA_LEFT,
            backColor=C_PURPLE, borderPadding=(6,8,6,8)),

        "footer_note": s("footer_note",
            fontSize=8, textColor=C_MED_GREY, spaceAfter=2,
            alignment=TA_CENTER, fontName="Helvetica-Oblique"),
    }

# ── table helper ──────────────────────────────────────────────────────────────
def styled_table(data, col_widths, header_bg=C_DARK_BLUE, alt_bg=C_LIGHT_BLUE):
    ts = TableStyle([
        ("BACKGROUND", (0,0), (-1,0), header_bg),
        ("TEXTCOLOR",  (0,0), (-1,0), C_WHITE),
        ("FONTNAME",   (0,0), (-1,0), "Helvetica-Bold"),
        ("FONTSIZE",   (0,0), (-1,0), 9),
        ("ALIGN",      (0,0), (-1,0), "CENTER"),
        ("VALIGN",     (0,0), (-1,-1), "MIDDLE"),
        ("FONTSIZE",   (0,1), (-1,-1), 9),
        ("FONTNAME",   (0,1), (-1,-1), "Helvetica"),
        ("TEXTCOLOR",  (0,1), (-1,-1), C_DARK_GREY),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [C_WHITE, alt_bg]),
        ("GRID",       (0,0), (-1,-1), 0.5, colors.HexColor("#bdbdbd")),
        ("TOPPADDING",  (0,0), (-1,-1), 5),
        ("BOTTOMPADDING",(0,0), (-1,-1), 5),
        ("LEFTPADDING", (0,0), (-1,-1), 6),
        ("RIGHTPADDING",(0,0), (-1,-1), 6),
    ])
    t = Table(data, colWidths=col_widths, repeatRows=1)
    t.setStyle(ts)
    return t

# ── build content ─────────────────────────────────────────────────────────────
def build_story(st):
    story = []
    sp = lambda n=1: Spacer(1, n*4*mm)
    hr = lambda c=C_DARK_BLUE, t=1: HRFlowable(width="100%", thickness=t, color=c, spaceAfter=4, spaceBefore=4)

    def P(text, style): return Paragraph(text, st[style])
    def B(text): return Paragraph(f"• {text}", st["body"])

    # ══════════════════════════════════════════════════════
    # COVER PAGE
    # ══════════════════════════════════════════════════════
    story += [
        sp(8),
        P("🌾 Agricultural Poisons", "cover_title"),
        sp(1),
        P("Chapter 25 | Pages 395–401", "cover_sub"),
        sp(1),
        P("The Essentials of Forensic Medicine & Toxicology", "cover_sub"),
        P("Dr. K.S. Narayan Reddy | 36th Edition (2026)", "cover_meta"),
        sp(2),
        hr(C_DARK_BLUE, 2),
        sp(1),
        P("Complete Study Notes • Memory Tricks • 10-Marker Q&A", "cover_meta"),
        P("Prepared for Exam Preparation", "cover_meta"),
        sp(10),
        P("⚠️ Study Tips: Read once to understand, twice to memorise, third time to write from memory!", "highlight"),
        PageBreak(),
    ]

    # ══════════════════════════════════════════════════════
    # BIG PICTURE
    # ══════════════════════════════════════════════════════
    story += [
        P("🧠 The Big Picture — What is Chapter 25 About?", "chapter_head"),
        sp(1),
        P("Imagine a farmer spraying his fields. The chemicals he uses to kill insects and weeds — if a human "
          "swallows them, inhales them, or if they touch the skin — these can KILL. Chapter 25 is all about "
          "<b>these farming chemicals as poisons</b>. There are 5 major agricultural poisons you must know cold.", "body"),
        sp(1),
    ]

    overview_data = [
        ["#", "Poison", "What It Is", "Key Word / Hook"],
        ["1", "Organophosphorus (OP)", "Insecticide", "AChE Killer (Irreversible)"],
        ["2", "Carbamates", "Insecticide", "Reversible AChE Killer"],
        ["3", "Chlorates", "Weedkiller", "MetHb + Hemolysis"],
        ["4", "Paraquat", "Herbicide", "Lung Destroyer"],
        ["5", "Aluminum Phosphide (ALP)", "Grain Preservative", "Garlic Smell + No Antidote"],
    ]
    story.append(styled_table(overview_data, [15*mm, 50*mm, 45*mm, 65*mm]))
    story.append(sp(2))

    # ══════════════════════════════════════════════════════
    # PART 1 — OP POISONS
    # ══════════════════════════════════════════════════════
    story += [
        P("🔴  PART 1: ORGANOPHOSPHORUS (OP) POISONS — THE MOST IMPORTANT!", "part_head"),
        sp(1),
        P("Think of it like this: Imagine a river called the <b>Acetylcholine River</b>. Normally, a cleaner "
          "called <b>AChE (Acetylcholinesterase)</b> cleans the river. OP compounds <b>DESTROY the cleaner</b>, "
          "so acetylcholine keeps flooding everywhere. The body goes into overdrive!", "body"),
    ]

    story.append(P("Compounds to Know", "section_head"))
    compounds_data = [
        ["Alkyl Phosphates", "Aryl Phosphates"],
        ["HETP, TEPP (Tetron), OMPA, Dimefox,\nMalathion (Kill Bug/Bugsolline),\nSulfotepp, Demeton, Trichlorfon",
         "Parathion (Nitrostigmine/Follidol) ← most common in India\nParaoxon, Methyl-parathion (Metacide),\nChlorothion, Diazinon (Diazion; Tik 20)"],
    ]
    t = Table(compounds_data, colWidths=[87*mm, 87*mm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,0), C_TEAL),
        ("TEXTCOLOR",  (0,0), (-1,0), C_WHITE),
        ("FONTNAME",   (0,0), (-1,0), "Helvetica-Bold"),
        ("FONTNAME",   (0,1), (-1,-1), "Helvetica"),
        ("FONTSIZE",   (0,0), (-1,-1), 9),
        ("TEXTCOLOR",  (0,1), (-1,-1), C_DARK_GREY),
        ("GRID",       (0,0), (-1,-1), 0.5, colors.HexColor("#bdbdbd")),
        ("VALIGN",     (0,0), (-1,-1), "TOP"),
        ("TOPPADDING",  (0,0), (-1,-1), 6),
        ("BOTTOMPADDING",(0,0), (-1,-1), 6),
        ("LEFTPADDING", (0,0), (-1,-1), 8),
    ]))
    story += [t, sp(1),
        P("🌟 Memory Trick: <b>Alkyl = Already toxic. Aryl = Activated by liver</b> (via Cytochrome P450)", "trick_box"),
        sp(1),
    ]

    story += [
        P("Absorption, Distribution &amp; Metabolism", "section_head"),
        B("Absorbed through: <b>skin, inhalation, mucous membranes, GI tract</b>"),
        B("Widely distributed; readily <b>cross placenta</b>"),
        B("Metabolism in liver via Cytochrome P450; Aryl types need liver activation"),
        B("Mixed with solvent <b>Aromax</b> → causes <b>kerosene-like smell</b> in stomach/vomit"),
        B("Excreted in urine; excretion prolonged over a week"),
        sp(1),
    ]

    story += [
        P("⚡ Mechanism of Action — THE HEART of OP Poisoning", "section_head"),
        P("<b>Normally:</b> Acetylcholine → AChE → Choline + Acetic Acid (all cleaned up!)<br/>"
          "<b>In OP poisoning:</b> Acetylcholine → AChE is BLOCKED by OP → Acetylcholine BUILDS UP everywhere!<br/>"
          "OP binds to AChE <b>IRREVERSIBLY</b> (this is the exam favourite!)", "code_box"),
        sp(1),
    ]

    effects_data = [
        ["Effect Type", "Receptor", "Key Symptoms", "Memory Trick"],
        ["MUSCARINIC\n(glands, smooth muscle)", "M receptors",
         "Salivation, Lacrimation, Urination,\nDefecation, GI cramps, Emesis,\nMiosis, Bradycardia, Bronchospasm",
         "SLUDGE\nSalivation, Lacrimation,\nUrination, Defecation,\nGI cramps, Emesis"],
        ["NICOTINIC\n(skeletal muscle, ganglia)", "N receptors",
         "Muscle fasciculations, Adrenal\nstimulation, Tachycardia (initially),\nCramps, Hypertension",
         "MATCH:\nMuscle fasciculations,\nAdrenal stim,\nTachycardia, Cramps,\nHypertension"],
        ["CNS", "Both M + N",
         "Anxiety, seizures, coma,\nrespiratory failure",
         "—"],
    ]
    story += [
        styled_table(effects_data, [40*mm, 28*mm, 60*mm, 47*mm], header_bg=C_RED),
        sp(1),
        P("🌟 DUMBELS trick for full muscarinic picture: <b>D</b>efecation, <b>U</b>rination, <b>M</b>iosis, "
          "<b>B</b>radycardia/Bronchospasm/Bronchorrhoea, <b>E</b>mesis, <b>L</b>acrimation, <b>S</b>alivation/Sweating",
          "trick_box"),
        sp(1),
    ]

    story += [
        P("Diagnosis", "section_head"),
        B("<b>Atropine Test:</b> Give 2 mg atropine IV. Normal person → dry mouth, racing heart. "
          "OP poisoning → symptoms IMPROVE without atropinization = CONFIRMED!"),
        B("<b>Cholinesterase Levels:</b>"),
        Paragraph("&nbsp;&nbsp;&nbsp;&nbsp;• Plasma pseudocholinesterase — more <b>sensitive</b>, falls FIRST",
                  st["body"]),
        Paragraph("&nbsp;&nbsp;&nbsp;&nbsp;• RBC true cholinesterase — more <b>diagnostic/specific</b>",
                  st["body"]),
        Paragraph("&nbsp;&nbsp;&nbsp;&nbsp;• RBC AChE &lt;50% of normal = <b>poisoning confirmed</b>",
                  st["body"]),
        Paragraph("&nbsp;&nbsp;&nbsp;&nbsp;• Plasma returns to normal in <b>7–10 days</b>; untreated: <b>4 weeks</b>",
                  st["body"]),
        P("🌟 Remember: <b>Plasma falls FIRST, RBC is MORE accurate for diagnosis</b>", "trick_box"),
        sp(1),
    ]

    story += [
        P("Post-Mortem Findings", "section_head"),
        B("Kerosene/garlic-like smell from mouth, body cavities, stomach contents"),
        B("Pinpoint pupils (miosis)"),
        B("Cyanosis"),
        B("Froth in airways (lungs)"),
        B("Congestion of lungs, liver, brain, kidneys"),
        B("Stomach contents smell of kerosene/aromax solvent"),
        sp(1),
    ]

    story += [
        P("💊 Treatment (Very Important for Exams!)", "section_head"),
        P("Step 1 — Remove from exposure", "sub_head"),
        B("Remove clothes; wash skin with soap + water, then ethanol + water or alkaline solution"),
        B("If eye involved: irrigate all conjunctival surfaces"),
        P("Step 2 — Airway", "sub_head"),
        B("Keep airway patent; tracheostomy may be needed"),
        P("Step 3 — Decontaminate GI (if ingested)", "sub_head"),
        B("Stomach wash with <b>1:5,000 potassium permanganate solution</b>"),
        B("Activated charcoal 1 g/kg; avoid ipecac"),
        B("Cathartic (sorbitol/magnesium citrate) once, unless diarrhoea present"),
        P("Step 4 — SPECIFIC ANTIDOTES: Remember 'A and P'", "sub_head"),
    ]

    antidote_data = [
        ["Drug", "Dose", "Action", "Key Points"],
        ["ATROPINE\n(Drug A)", "2–4 mg IV initially\n(Peds: 0.05 mg/kg)\nDouble every 10–15 min\nUp to 40–2000 mg/day",
         "Blocks muscarinic effects\n(No effect on nicotinic)\nCounteracts CNS effects",
         "• End-point = DRY secretions\n  NOT pupil size!\n• Avoid if HR >140 bpm\n• Ineffective in severe\n  hypoxia/hypotension"],
        ["PAM / Pralidoxime\n2-PAM\n(Drug P)", "1–2 g IV over 15–30 min\n(Peds: 20–40 mg/kg)\nRepeat after 1–2 hrs",
         "REACTIVATES AChE —\nthe ONLY drug that\nreverses the actual block!",
         "• Must give EARLY!\n• After 'aging' (24–48 hrs)\n  PAM won't work\n• Reduces nicotinic\n  symptoms"],
    ]
    story += [
        styled_table(antidote_data, [30*mm, 40*mm, 50*mm, 55*mm], header_bg=C_GREEN),
        sp(1),
        P("⛔ AVOID these drugs: Physostigmine, Edrophonium chloride, Succinylcholine — they WORSEN the situation!",
          "warning_box"),
        sp(2),
    ]

    # ══════════════════════════════════════════════════════
    # PART 2 — CARBAMATES
    # ══════════════════════════════════════════════════════
    story += [
        P("🔵  PART 2: CARBAMATES", "part_head"),
        sp(1),
        P("Carbamates work the same way as OP — they inhibit AChE — but the key difference is the inhibition "
          "is <b>REVERSIBLE</b>. Think of it as a temporary glue vs. OP's permanent superglue.", "body"),
        sp(1),
    ]

    carb_data = [
        ["Feature", "OP Compounds", "Carbamates"],
        ["Mechanism", "Irreversible AChE inhibition", "REVERSIBLE AChE inhibition"],
        ["Severity", "More severe, prolonged", "Less severe, self-limiting"],
        ["PAM (Pralidoxime)", "YES — essential", "NOT needed / usually avoided"],
        ["Atropine", "YES — essential", "YES — essential"],
        ["Examples", "Parathion, Malathion", "Carbaryl (Sevin), Aldicarb, Carbofuran"],
    ]
    story += [
        styled_table(carb_data, [38*mm, 62*mm, 75*mm], header_bg=C_TEAL),
        sp(1),
        P("🌟 Memory Trick: 'Carbamates Can reverse — Choose no PAM' (3 C's)", "trick_box"),
        sp(2),
    ]

    # ══════════════════════════════════════════════════════
    # PART 3 — CHLORATES
    # ══════════════════════════════════════════════════════
    story += [
        P("🟡  PART 3: CHLORATES (Weedkillers)", "part_head"),
        sp(1),
        P("Think of chlorates as <b>blood cell destroyers</b>. They look like table sugar (sodium chlorate) "
          "— so accidental ingestion is common!", "body"),
        sp(1),
        P("Key Facts", "section_head"),
    ]

    chlorate_facts = [
        ["Property", "Details"],
        ["Used as", "Weed killers, match heads, fireworks"],
        ["Appearance", "Sodium chlorate resembles TABLE SUGAR — accidental ingestion risk!"],
        ["Fatal Dose", "~20–30 g"],
        ["Mechanism", "Powerful oxidising agent → attacks all body cells\n"
                       "Reacts with thiol groups on RBCs → HEMOLYSIS\n"
                       "Oxidises Hb → METHEMOGLOBIN (can't carry O₂!)\n"
                       "Potent NEPHROTOXIN; hemolysis releases K⁺ → fatal hyperkalemia"],
    ]
    story += [
        styled_table(chlorate_facts, [40*mm, 135*mm], header_bg=C_AMBER),
        sp(1),
        P("Symptoms (onset 1–4 hours)", "section_head"),
        B("Nausea, vomiting, diarrhoea, abdominal pain"),
        B("Shallow breathing"),
        B("Blood/protein/haemoglobin in urine (haematuria, proteinuria, haemoglobinuria)"),
        B("Oliguria/anuria → <b>renal failure</b> (main cause of death)"),
        B("<b>Haemolysis + jaundice + hepatic failure</b>"),
        B("<b>Methemoglobinaemia</b> — can reach 40% or above"),
        B("Agitation, muscular twitchings, convulsions"),
        B("Skin/eyes: irritation, redness, burns, ulcers"),
        P("Treatment", "section_head"),
    ]

    chlorate_tx = [
        ["Step", "Treatment"],
        ["1", "Stomach wash (gastric lavage)"],
        ["2", "Methylene blue — 25 mL of 1% solution IV (for methemoglobinaemia)"],
        ["3", "Sodium thiosulphate — 2–5 g in 200 mL of 5% sodium bicarbonate as drink"],
        ["4", "Ascorbic acid — 1 g every 4 hours (drink or slow IV)"],
        ["5", "Peritoneal dialysis or haemodialysis"],
        ["6", "Symptomatic management"],
    ]
    story += [
        styled_table(chlorate_tx, [12*mm, 163*mm], header_bg=C_AMBER),
        sp(1),
        P("🌟 Mnemonic for chlorate treatment: '<b>WASH MB STA</b>' — Wash stomach, Methylene Blue, "
          "Sodium Thiosulphate, Ascorbic acid, dialysis", "trick_box"),
        sp(2),
    ]

    # ══════════════════════════════════════════════════════
    # PART 4 — PARAQUAT
    # ══════════════════════════════════════════════════════
    story += [
        P("🟠  PART 4: PARAQUAT — 'The Lung Killer'", "part_head"),
        sp(1),
        P("Paraquat is a <b>bipyridylium herbicide</b> (weed killer). It is the most dangerous herbicide known. "
          "Once ingested in significant quantity, it almost always kills.", "body"),
        sp(1),
    ]

    paraquat_facts = [
        ["Property", "Details"],
        ["Trade names", "Gramoxone (brownish liquid, 10–30%); Weedol (brown granules, ~5%)"],
        ["Use", "Sprayed on weeds BEFORE planting. Becomes inactivated on contact with soil."],
        ["Main route", "Ingestion (fatalities); inhalational deaths during spraying are VERY RARE"],
        ["Mechanism", "NADPH-dependent reduction → FREE RADICALS\n"
                       "Free radicals + O₂ → Superoxide + Hydroxyl radicals (OH·)\n"
                       "→ Disrupts cell structure and causes cell death\n"
                       "Lungs concentrate paraquat via polyamine uptake system → lungs are #1 target"],
    ]
    story += [
        styled_table(paraquat_facts, [35*mm, 140*mm], header_bg=C_AMBER),
        sp(1),
        P("Clinical Phases", "section_head"),
    ]

    pq_phases = [
        ["Phase", "Timing", "Features"],
        ["Phase 1", "Early (24–48 hrs)", "Nausea, vomiting, diarrhoea, abdominal pain,\nulceration of mouth/throat (corrosive)"],
        ["Phase 2", "Days 3–14", "ARDS, PULMONARY FIBROSIS (the killer!), renal failure, liver damage"],
        ["Phase 3", "Late", "Irreversible lung fibrosis → death by respiratory failure"],
    ]
    story += [
        styled_table(pq_phases, [25*mm, 35*mm, 115*mm], header_bg=C_AMBER),
        sp(1),
        P("🌟 Most tested fact: <b>Paraquat = Pulmonary Fibrosis</b>", "trick_box"),
        P("⛔ WARNING: HIGH-DOSE OXYGEN IS CONTRAINDICATED IN PARAQUAT POISONING! "
          "Oxygen increases free radical formation and WORSENS lung damage. This is a favourite exam trick!",
          "warning_box"),
        P("Treatment", "section_head"),
        B("NO specific antidote (very important exam point!)"),
        B("Fuller's earth (bentonite) — adsorbs paraquat in gut"),
        B("Gastric lavage"),
        B("Haemoperfusion (to remove from blood)"),
        B("Immunosuppression: steroids + cyclophosphamide (to slow fibrosis)"),
        B("Supportive care"),
        P("🌟 'The THREE NOs of Paraquat: No antidote, No O₂ (high dose), No cure if severe'", "trick_box"),
        sp(2),
    ]

    # ══════════════════════════════════════════════════════
    # PART 5 — ALP
    # ══════════════════════════════════════════════════════
    story += [
        P("🟤  PART 5: ALUMINUM PHOSPHIDE (ALP) — 'The Grain Poison'", "part_head"),
        sp(1),
        P("ALP is one of the most lethal agricultural poisons in India, especially in rural areas. "
          "It is used for preserving stored grains (wheat, rice) against insects and rodents.", "body"),
        sp(1),
    ]

    alp_facts = [
        ["Property", "Details"],
        ["Trade names", "Celphos, Phostoxin, Quickphos"],
        ["Formulations", "Tablets (3 g each), pellets (0.6 g each), powder"],
        ["Fatal Dose", "1 tablet = 3 g — very small, very lethal!"],
        ["Smell", "GARLIC-LIKE odor (key exam point)"],
        ["Mechanism", "ALP + moisture/HCl in stomach → Phosphine gas (PH₃)\n"
                       "Phosphine → inhibits mitochondrial cytochrome c oxidase\n"
                       "→ blocks electron transport chain → cellular energy failure → cell death"],
        ["Main cause of death", "CARDIOVASCULAR COLLAPSE (cardiac failure)"],
    ]
    story += [
        styled_table(alp_facts, [40*mm, 135*mm], header_bg=C_DARK_GREY),
        sp(1),
        P("Symptoms", "section_head"),
        B("<b>GI:</b> Nausea, vomiting, abdominal pain, GI bleeding"),
        B("<b>CVS:</b> Hypotension, arrhythmias, cardiac failure (main cause of death!)"),
        B("<b>Respiratory:</b> ARDS, pulmonary oedema, cyanosis"),
        B("<b>CNS:</b> Anxiety, restlessness, ataxia, convulsions, coma"),
        B("<b>Metabolic:</b> Metabolic acidosis"),
        B("Appear within 30 minutes to a few hours of ingestion"),
        sp(1),
        P("Forensic Test for ALP", "section_head"),
        P("<b>Silver Nitrate Paper Test:</b> Phosphine gas turns silver nitrate paper <b>BLACK</b>. "
          "This is the important forensic confirmatory test!", "highlight"),
        sp(1),
        P("Post-Mortem Appearances", "section_head"),
        B("Garlic-like odor at mouth, nostrils, and gastric contents"),
        B("Blood-stained froth at mouth and nostrils"),
        B("Congested mucous membrane of lower oesophagus, stomach, duodenum"),
        B("Decreasing congestion in small intestine"),
        B("Lungs, liver, spleen, kidneys, brain — all congested"),
        B("<b>Centrizonal haemorrhagic necrosis of liver</b>"),
        sp(1),
        P("Histopathology", "section_head"),
    ]

    histo_data = [
        ["Organ", "Histopathological Changes"],
        ["Stomach", "Congestion, oedema, leucocytic infiltration, sloughing of gastric mucosa"],
        ["Lungs", "Congestion, oedema, desquamation of respiratory epithelium,\nthickened alveoli, lymphocytic infiltration"],
        ["Kidneys", "Congestion, necrosis, tubular degeneration and regeneration"],
        ["Adrenals", "Congestion, haemorrhage, necrosis"],
    ]
    story += [
        styled_table(histo_data, [30*mm, 145*mm], header_bg=C_DARK_GREY),
        sp(1),
        P("Treatment (NO specific antidote!)", "section_head"),
    ]

    alp_tx = [
        ["Step", "Treatment"],
        ["1", "Gastric lavage with potassium permanganate after endotracheal intubation\n"
              "(oxidises phosphine → non-toxic phosphate); repeat 2–3 times"],
        ["2", "Activated charcoal 100 g orally mixed with SORBITOL (NOT water),\n"
              "240 mL per 30 g — to adsorb phosphine"],
        ["3", "Antacids — reduce symptoms + reduce absorption of phosphine"],
        ["4", "Liquid paraffin — helps excretion of ALP and phosphine from gut"],
        ["5", "NO specific antidote"],
        ["6", "Magnesium sulphate — 1 g IV; then 1–1.5 g every 6 hrs for 5–7 days\n"
              "(reduces organ toxicity, corrects hypomagnesaemia + arrhythmias)"],
        ["7", "Fluids for shock: 4–6 litres in first 3–6 hours (50% normal saline)"],
        ["8", "Low-dose dopamine: 4–6 mcg/kg/min (cardiac support)"],
        ["9", "IV Hydrocortisone: 400 mg every 4–6 hours (highly effective; reduces dopamine dose)"],
        ["10", "Oxygen for hypoxia; IV sodium carbonate for metabolic acidosis"],
        ["11", "Peritoneal or haemodialysis"],
    ]
    story += [
        styled_table(alp_tx, [12*mm, 163*mm], header_bg=C_DARK_GREY),
        sp(2),
        PageBreak(),
    ]

    # ══════════════════════════════════════════════════════
    # MASTER COMPARISON TABLE
    # ══════════════════════════════════════════════════════
    story += [
        P("📊 MASTER COMPARISON TABLE — Exam Gold!", "chapter_head"),
        sp(1),
    ]

    master_data = [
        ["Feature", "OP", "Carbamate", "Chlorate", "Paraquat", "ALP"],
        ["Use", "Insecticide", "Insecticide", "Weedkiller", "Herbicide", "Grain preservative"],
        ["Mechanism", "Irreversible\nAChE inhibition", "Reversible\nAChE inhibition",
         "MetHb +\nHaemolysis +\nNephrotoxin", "Free radicals\n→ lung damage", "Phosphine\n→ mito block"],
        ["Key symptom", "SLUDGE +\nMiosis", "Milder SLUDGE", "MetHb +\nRenal failure",
         "Pulmonary\nFibrosis", "Cardiac failure\n+ garlic smell"],
        ["Antidote", "Atropine +\nPAM", "Atropine\nonly", "Methylene\nblue", "NONE", "NONE"],
        ["PAM useful?", "YES", "NO", "No", "No", "No"],
        ["Smell", "Kerosene/\ngarlic", "—", "—", "—", "Garlic"],
        ["Key test", "Atropine test\nAChE levels", "—", "MetHb level", "—", "Silver nitrate\npaper → black"],
        ["Main COD", "Respiratory\nfailure", "Respiratory\nfailure", "Renal failure", "Respiratory\nfailure/fibrosis",
         "Cardiovascular\ncollapse"],
    ]
    story += [
        styled_table(master_data, [30*mm, 29*mm, 29*mm, 29*mm, 29*mm, 29*mm]),
        sp(2),
    ]

    # ══════════════════════════════════════════════════════
    # WARNINGS BOX
    # ══════════════════════════════════════════════════════
    story += [
        P("⚠️  CRITICAL EXAM WARNINGS — Do NOT Get These Wrong!", "chapter_head"),
        sp(1),
        P("⛔ 1. PARAQUAT + HIGH-DOSE OXYGEN = DANGEROUS! High-dose O₂ increases free radical formation "
          "and WORSENS lung damage. Very common trick question.", "warning_box"),
        sp(1),
        P("⛔ 2. PAM (Pralidoxime) MUST be given EARLY — once 'aging' occurs (AChE-OP bond becomes permanent, "
          "~24–48 hrs), PAM won't work. Never give PAM late and expect results.", "warning_box"),
        sp(1),
        P("⛔ 3. ALP HAS NO ANTIDOTE — pure supportive treatment; very high mortality. "
          "Students often write atropine for ALP — WRONG!", "warning_box"),
        sp(1),
        P("⛔ 4. ATROPINE END-POINT IS DRY SECRETIONS, NOT PUPILS — do not stop atropine based on "
          "pupil size. This is the number one clinical error in OP poisoning.", "warning_box"),
        sp(1),
        P("⛔ 5. CARBAMATES — PAM is usually NOT used/needed (sometimes even avoided in some references). "
          "Remember: reversible = no need to reactivate!", "warning_box"),
        sp(1),
        P("⛔ 6. SODIUM CHLORATE LOOKS LIKE TABLE SUGAR — this is why accidental ingestion is common. "
          "A history of 'mistook white powder for sugar' = think chlorate!", "warning_box"),
        sp(2),
    ]

    # ══════════════════════════════════════════════════════
    # MEMORY TRICKS SUMMARY
    # ══════════════════════════════════════════════════════
    story += [
        P("🧠 MEMORY TRICKS SUMMARY", "chapter_head"),
        sp(1),
    ]

    tricks_data = [
        ["Mnemonic / Trick", "What It Helps You Remember"],
        ["SLUDGE", "Muscarinic symptoms: Salivation, Lacrimation, Urination, Defecation, GI cramps, Emesis"],
        ["DUMBELS", "Full muscarinic picture: Defecation, Urination, Miosis, Bradycardia/Bronchospasm,\n"
                    "Emesis, Lacrimation, Salivation/Sweating"],
        ["'A and P' antidotes", "Atropine (muscarinic block) + PAM/Pralidoxime (nicotinic + reactivation of AChE)"],
        ["'Carbamates Can reverse —\nChoose no PAM' (3 C's)", "Reversible inhibition; no PAM needed"],
        ["'THREE NOs of Paraquat'", "No antidote, No high-dose O₂, No cure if severe"],
        ["'Gramoxone = Grass Gone'", "Trade name for Paraquat"],
        ["'Celphos = Cell-phosphide'", "Trade name for Aluminum Phosphide"],
        ["'ALP = Garlic + Grain +\nNo Antidote'", "Three key ALP facts"],
        ["'Plasma falls FIRST,\nRBC is MORE accurate'", "Interpretation of cholinesterase levels in OP poisoning"],
        ["'WASH MB STA'", "Chlorate treatment: Wash stomach → Methylene Blue → Sodium Thiosulphate →\nAscorbic acid → dialysis"],
        ["'Alkyl = Already toxic;\nAryl = Activated by liver'", "Difference between alkyl and aryl phosphates in OP"],
    ]
    story += [
        styled_table(tricks_data, [55*mm, 120*mm], header_bg=C_PURPLE, alt_bg=C_LIGHT_PURP),
        sp(2),
        PageBreak(),
    ]

    # ══════════════════════════════════════════════════════
    # 10-MARKER QUESTION
    # ══════════════════════════════════════════════════════
    story += [
        P("✍️  10-MARKER EXAM QUESTION &amp; MODEL ANSWER", "q_head"),
        sp(1),
        P("<b>Question:</b> Describe the toxicology of Organophosphorus poisoning. Include its mechanism of "
          "action, clinical features, post-mortem findings, and treatment. <i>(10 Marks)</i>", "highlight"),
        sp(1),
    ]

    answer_sections = [
        ("Introduction — 1 Mark",
         "Organophosphorus (OP) compounds are esters of phosphoric acid widely used as insecticides in agriculture. "
         "They are among the most common causes of poisoning in India. They form two series: "
         "(1) Alkyl phosphates (e.g., Malathion, TEPP) and (2) Aryl phosphates (e.g., Parathion/Follidol, Methyl-parathion)."),

        ("Absorption and Metabolism — 1 Mark",
         "OP compounds are absorbed through skin, inhalation, mucous membranes, and the GI tract. They are widely "
         "distributed and cross the placenta. Metabolism occurs in the liver via cytochrome P450. Aryl phosphates require "
         "liver activation. They are mixed with solvent (Aromax) causing a kerosene-like smell. Excreted in urine over ~1 week."),

        ("Mechanism of Action — 2 Marks",
         "Normally, acetylcholine (ACh) released at nerve synapses is broken down by AChE. OP compounds bind "
         "<b>irreversibly</b> to AChE, preventing breakdown of ACh. Accumulated ACh causes:<br/>"
         "• <b>Muscarinic effects (SLUDGE):</b> Salivation, Lacrimation, Urination, Defecation, GI cramps, Emesis; "
         "plus miosis, bradycardia, bronchospasm<br/>"
         "• <b>Nicotinic effects:</b> Muscle fasciculations, weakness, hypertension, tachycardia (initially)<br/>"
         "• <b>CNS effects:</b> Anxiety, convulsions, coma, respiratory failure"),

        ("Clinical Features — 1 Mark",
         "Onset within minutes to hours. Key features: profuse sweating, hypersalivation, lacrimation, "
         "<b>pinpoint pupils (miosis)</b>, bradycardia, bronchospasm, muscle fasciculations, urinary incontinence, "
         "convulsions, and death from respiratory failure."),

        ("Diagnosis — 1 Mark",
         "1. <b>Atropine test:</b> 2 mg IV atropine — no atropinisation confirms OP poisoning.<br/>"
         "2. <b>Cholinesterase levels:</b> Plasma (sensitive, falls first); RBC (&lt;50% normal confirms poisoning). "
         "Plasma normalises in 7–10 days; untreated cases need 4 weeks."),

        ("Post-Mortem Findings — 1 Mark",
         "Kerosene/garlic-like smell; pinpoint pupils; cyanosis; froth in airways; "
         "congestion of lungs, liver, kidneys, brain; gastric contents smelling of kerosene/solvent."),

        ("Treatment — 3 Marks",
         "1. Remove from exposure; wash skin with soap, water, and ethanol.<br/>"
         "2. Gastric lavage with 1:5,000 KMnO₄ solution; activated charcoal 1 g/kg.<br/>"
         "3. <b>Atropine sulphate:</b> 2–4 mg IV initially; double every 10–15 min; up to 40–2,000 mg/day; "
         "end-point is dry secretions (NOT pupils).<br/>"
         "4. <b>Pralidoxime (2-PAM):</b> 1–2 g IV over 15–30 min; must be given EARLY before aging; reactivates AChE; "
         "reduces nicotinic symptoms.<br/>"
         "5. AVOID: physostigmine, succinylcholine, edrophonium chloride.<br/>"
         "6. Supportive: airway management, tracheostomy if needed, treat seizures."),
    ]

    for title, text in answer_sections:
        story += [
            P(title, "sub_head"),
            P(text, "body"),
            sp(1),
        ]

    # ══════════════════════════════════════════════════════
    # LAST-NIGHT RECAP
    # ══════════════════════════════════════════════════════
    story += [
        PageBreak(),
        P("📌 LAST-NIGHT-BEFORE-EXAM QUICK RECAP CARD", "chapter_head"),
        sp(1),
        P("OP POISONING:\n"
          "→ Irreversible AChE inhibition\n"
          "→ SLUDGE (muscarinic) + Fasciculations (nicotinic) + Coma (CNS)\n"
          "→ Pinpoint pupils, kerosene smell, excessive secretions\n"
          "→ Antidote: ATROPINE (muscarinic) + PAM (reactivation)\n"
          "→ Confirm: Atropine test + AChE levels (<50% RBC = poisoned)", "code_box"),
        sp(1),
        P("CARBAMATES:\n"
          "→ Like OP but REVERSIBLE → Atropine only, no PAM needed\n"
          "→ Less severe, self-limiting", "code_box"),
        sp(1),
        P("CHLORATES (Weedkiller):\n"
          "→ Oxidising agent → MetHb + Haemolysis + Renal failure\n"
          "→ Antidote: Methylene blue\n"
          "→ Treatment mnemonic: WASH MB STA", "code_box"),
        sp(1),
        P("PARAQUAT (Gramoxone, Herbicide):\n"
          "→ Free radicals → PULMONARY FIBROSIS\n"
          "→ NO antidote, NO high-dose O₂, Fuller's earth\n"
          "→ Highest mortality", "code_box"),
        sp(1),
        P("ALP (Celphos, Grain Preservative):\n"
          "→ Phosphine gas → Mitochondrial block → CARDIAC FAILURE\n"
          "→ Garlic smell, NO antidote\n"
          "→ Treatment: Magnesium sulphate + Hydrocortisone + Supportive", "code_box"),
        sp(2),
        hr(C_DARK_BLUE, 2),
        sp(1),
        P("Source: The Essentials of Forensic Medicine and Toxicology, 36th Edition (2026), Dr. K.S. Narayan Reddy, "
          "Chapter 25: Agricultural Poisons, Pages 395–401",
          "footer_note"),
        P("Study tip: Read 3 times. 1st — understand the story. 2nd — cover the right column, test yourself. "
          "3rd — write the 10-marker from memory. You will ace your exams!",
          "footer_note"),
    ]

    return story


# ── main ──────────────────────────────────────────────────────────────────────
def main():
    styles = build_styles()
    doc = SimpleDocTemplate(
        OUTPUT,
        pagesize=A4,
        leftMargin=18*mm,
        rightMargin=18*mm,
        topMargin=20*mm,
        bottomMargin=20*mm,
        title="Agricultural Poisons — FMT Chapter 25",
        author="Narayan Reddy FMT Study Notes",
        subject="Forensic Medicine & Toxicology — Agricultural Poisons",
    )
    story = build_story(styles)
    doc.build(story)
    print(f"PDF created: {OUTPUT}")


if __name__ == "__main__":
    main()