const pptxgen = require("pptxgenjs");
const { execSync } = require("child_process");

// ── Fetch images ──────────────────────────────────────────────────────────────
const imgUrls = [
  "https://cdn.orris.care/cdss_images/pmc_clinical_VQA_f8dbf9a0401d7490eb41f3739219b79ded37bcca788b00b1e8efca32aa66b099.jpg",
  "https://cdn.orris.care/cdss_images/HARRISON_1763036071170_b52af39c-ae90-4f8b-9826-2f200ccfcfd6.png",
  "https://cdn.orris.care/cdss_images/pmc_clinical_VQA_8fdd1550f591aa025e29843049a3a66072520c600f105eb5ce8ffb802ef998ea.jpg"
];

let imgs = [];
try {
  const raw = execSync(
    `node /home/daytona/skills/shared/scripts/fetch_images.js ${imgUrls.map(u => `"${u}"`).join(" ")}`,
    { maxBuffer: 50 * 1024 * 1024 }
  ).toString();
  imgs = JSON.parse(raw);
} catch(e) {
  console.warn("Image fetch failed:", e.message);
  imgs = imgUrls.map(u => ({ url: u, base64: null, error: e.message }));
}

// ── Color Palette ─────────────────────────────────────────────────────────────
const C = {
  bg:       "0D1B2A",   // deep navy
  accent1:  "C0392B",   // crimson (sickle/blood)
  accent2:  "E67E22",   // amber
  accent3:  "27AE60",   // green
  accent4:  "2980B9",   // blue
  white:    "FFFFFF",
  offwhite: "ECF0F1",
  grey:     "BDC3C7",
  darkcard: "1A2940",
  midcard:  "14243A",
};

// ── Helpers ───────────────────────────────────────────────────────────────────
function hdr(slide, text, sub) {
  slide.addShape("rect", { x: 0, y: 0, w: 10, h: 1.1, fill: { color: C.accent1 } });
  slide.addText(text, {
    x: 0.3, y: 0.08, w: 9.4, h: 0.7,
    fontSize: 26, bold: true, color: C.white, fontFace: "Calibri", margin: 0
  });
  if (sub) {
    slide.addText(sub, {
      x: 0.3, y: 0.72, w: 9.4, h: 0.35,
      fontSize: 13, color: "FDEBD0", fontFace: "Calibri", margin: 0
    });
  }
  slide.addShape("rect", { x: 0, y: 0, w: 0.18, h: 1.1, fill: { color: C.accent2 } });
}

function card(slide, x, y, w, h, title, bullets, titleColor, bgColor) {
  bgColor = bgColor || C.darkcard;
  titleColor = titleColor || C.accent2;
  slide.addShape("rect", {
    x, y, w, h,
    fill: { color: bgColor },
    line: { color: titleColor, width: 1.2 },
    shadow: { type: "outer", color: "000000", blur: 6, offset: 3, angle: 135, opacity: 0.3 }
  });
  slide.addText(title, {
    x: x + 0.12, y: y + 0.08, w: w - 0.2, h: 0.38,
    fontSize: 13, bold: true, color: titleColor, fontFace: "Calibri", margin: 0
  });
  const items = bullets.map((b, i) => ({
    text: b,
    options: { bullet: { type: "bullet" }, color: C.offwhite, fontSize: 10.5, fontFace: "Calibri", breakLine: i < bullets.length - 1 }
  }));
  slide.addText(items, {
    x: x + 0.12, y: y + 0.5, w: w - 0.22, h: h - 0.6,
    valign: "top", margin: 0
  });
}

function bgFill(slide) {
  slide.background = { color: C.bg };
}

function footerSlide(slide, num, total) {
  slide.addShape("rect", { x: 0, y: 5.35, w: 10, h: 0.28, fill: { color: C.midcard } });
  slide.addText("Sickle Cell Disease in Paediatrics  |  Expert Haematology Review", {
    x: 0.3, y: 5.36, w: 7, h: 0.24, fontSize: 8.5, color: C.grey, fontFace: "Calibri", margin: 0
  });
  slide.addText(`${num} / ${total}`, {
    x: 8.9, y: 5.36, w: 0.8, h: 0.24, fontSize: 8.5, color: C.grey, fontFace: "Calibri", align: "right", margin: 0
  });
}

// ─────────────────────────────────────────────────────────────────────────────
const pres = new pptxgen();
pres.layout = "LAYOUT_16x9";
pres.title = "Sickle Cell Disease in Paediatrics";
const TOTAL = 18;

// ══ SLIDE 1 — TITLE ══════════════════════════════════════════════════════════
{
  const sl = pres.addSlide();
  sl.background = { color: C.bg };
  // Large bold accent stripe
  sl.addShape("rect", { x: 0, y: 0, w: 10, h: 5.625, fill: { color: C.bg } });
  sl.addShape("rect", { x: 0, y: 0, w: 0.45, h: 5.625, fill: { color: C.accent1 } });
  sl.addShape("rect", { x: 0, y: 4.7, w: 10, h: 0.93, fill: { color: C.accent1 } });

  sl.addText("SICKLE CELL DISEASE", {
    x: 0.7, y: 0.55, w: 8.8, h: 1.1,
    fontSize: 44, bold: true, color: C.white, fontFace: "Calibri", charSpacing: 3
  });
  sl.addText("IN PAEDIATRICS", {
    x: 0.7, y: 1.55, w: 8.8, h: 0.7,
    fontSize: 32, bold: false, color: C.accent2, fontFace: "Calibri", charSpacing: 2
  });
  sl.addText("Comprehensive Exam Review  |  Long Answer · Short Answer · MCQ", {
    x: 0.7, y: 2.35, w: 8.8, h: 0.5,
    fontSize: 14, color: C.grey, fontFace: "Calibri"
  });
  sl.addText("Expert Haematologist Perspective  •  Pathophysiology to Management", {
    x: 0.7, y: 2.85, w: 8.8, h: 0.4,
    fontSize: 12, color: C.grey, fontFace: "Calibri", italic: true
  });

  if (imgs[1] && imgs[1].base64) {
    sl.addImage({ data: imgs[1].base64, x: 7.5, y: 1.2, w: 2.2, h: 2.2, rounding: true });
  }

  sl.addText("Sources: Tintinalli's Emergency Medicine · Rosen's Emergency Medicine · Henry's Clinical Lab Methods · Swanson's Family Medicine Review", {
    x: 0.3, y: 4.75, w: 9.4, h: 0.4,
    fontSize: 8, color: "FDEBD0", fontFace: "Calibri"
  });
}

// ══ SLIDE 2 — OUTLINE ════════════════════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl); hdr(sl, "Lecture Outline", "Key exam themes covered in this deck");
  footerSlide(sl, 2, TOTAL);
  const topics = [
    ["01", "Definition, Genetics & Epidemiology", C.accent4],
    ["02", "Molecular Pathophysiology (HbS mutation → polymerisation)", C.accent1],
    ["03", "Vaso-occlusion cascade & endothelial dysfunction", C.accent1],
    ["04", "Clinical Types & Haemoglobin Genotypes", C.accent2],
    ["05", "Acute Crises — VOC, ACS, Splenic Sequestration, Aplastic, Stroke", C.accent2],
    ["06", "Chronic Complications (Organ damage)", C.accent3],
    ["07", "Diagnosis — Newborn Screening, Electrophoresis, Lab Findings", C.accent4],
    ["08", "Management — Analgesia, Hydroxyurea, Transfusion, HSCT", C.accent3],
    ["09", "Prevention — Penicillin, Vaccines, TCD Screening", C.accent3],
    ["10", "MCQ Bank + Short Answer Key Points", C.accent2],
  ];
  topics.forEach(([num, text, col], i) => {
    const row = Math.floor(i / 2), colIdx = i % 2;
    const x = 0.3 + colIdx * 4.85, y = 1.25 + row * 0.82;
    sl.addShape("rect", { x, y, w: 4.6, h: 0.68, fill: { color: C.darkcard }, line: { color: col, width: 1 } });
    sl.addText(`${num}`, { x: x + 0.1, y: y + 0.1, w: 0.45, h: 0.45, fontSize: 16, bold: true, color: col, fontFace: "Calibri", margin: 0 });
    sl.addText(text, { x: x + 0.6, y: y + 0.1, w: 3.9, h: 0.48, fontSize: 11, color: C.offwhite, fontFace: "Calibri", valign: "middle", margin: 0 });
  });
}

// ══ SLIDE 3 — DEFINITION & GENETICS ══════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Definition, Genetics & Epidemiology", "Long Answer — Foundational Concepts");
  footerSlide(sl, 3, TOTAL);

  card(sl, 0.2, 1.2, 4.65, 2.1, "🔬 Genetic Basis", [
    "Autosomal RECESSIVE — both β-globin alleles mutated",
    "Point mutation: adenine→thymine in β-globin gene",
    "Amino acid change: Glutamic acid → Valine at position 6 of β-chain",
    "HbSS (homozygous) = most severe disease; >85% HbS",
    "Other genotypes: HbSC, HbS-β⁺thal, HbS-β⁰thal"
  ], C.accent1);

  card(sl, 0.2, 3.4, 4.65, 2.0, "🌍 Epidemiology", [
    "~100,000 people in USA affected; 1/365 African-American births",
    "1 in 13 African-Americans carries sickle cell trait (HbAS)",
    "Also: Mediterranean, Indian, Middle Eastern, Caribbean",
    "~250,000 new births/year globally",
    "Heterozygous trait (HbAS) confers partial malaria protection"
  ], C.accent4);

  card(sl, 5.15, 1.2, 4.65, 2.1, "🧬 Haemoglobin Types", [
    "HbA (α²β²) — normal adult, >95% in adults",
    "HbF (α²γ²) — fetal Hb; NO β-globin → NO sickling in newborns",
    "HbS (α²βˢ²) — abnormal sickle Hb",
    "Symptoms begin as HbF declines (after ~6 months of age)",
    "HbA2 (α²δ²) — minor adult component"
  ], C.accent2);

  card(sl, 5.15, 3.4, 4.65, 2.0, "📋 Exam Key Points", [
    "Inheritance: autosomal recessive (both parents must carry gene)",
    "Trait (HbAS): ~40% HbS, usually asymptomatic",
    "MCQ: glutamic acid REPLACED by valine (not lysine, not Hb C)",
    "HbF protective — fetal period is symptom-free",
    "Screening: neonatal Hb electrophoresis (universal in many countries)"
  ], C.accent3);
}

// ══ SLIDE 4 — MOLECULAR PATHOPHYSIOLOGY ═════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Molecular Pathophysiology", "Long Answer — The HbS Polymerisation Cascade");
  footerSlide(sl, 4, TOTAL);

  // Flow diagram: 5 boxes in a cascade
  const steps = [
    { label: "Deoxygenation", desc: "HbS exposed to low O₂ tension", col: C.accent1 },
    { label: "HbS Polymerisation", desc: "Hydrophobic Val-6 exposes valine pocket → HbS tetramers aggregate into long rigid fibres (Hb polymer)", col: C.accent1 },
    { label: "RBC Sickling", desc: "Flexible biconcave disc → rigid crescent/sickle cell; membrane damage; irreversible sickling with repeated episodes", col: C.accent2 },
    { label: "Vascular Effects", desc: "↑ blood viscosity, sludging, RBC-endothelial adhesion, microvascular obstruction → tissue ischaemia", col: C.accent2 },
    { label: "Haemolysis", desc: "RBC lifespan 20 days (normal 120 days); chronic anaemia; free Hb scavenges NO → endothelial dysfunction", col: C.accent3 },
  ];

  steps.forEach((s, i) => {
    const y = 1.22 + i * 0.84;
    sl.addShape("rect", { x: 0.25, y, w: 9.5, h: 0.72, fill: { color: C.darkcard }, line: { color: s.col, width: 1.5 } });
    sl.addShape("rect", { x: 0.25, y, w: 0.38, h: 0.72, fill: { color: s.col } });
    sl.addText(`${i+1}`, { x: 0.25, y, w: 0.38, h: 0.72, fontSize: 18, bold: true, color: C.white, fontFace: "Calibri", align: "center", valign: "middle", margin: 0 });
    sl.addText(s.label, { x: 0.75, y: y + 0.05, w: 2.5, h: 0.35, fontSize: 12, bold: true, color: s.col, fontFace: "Calibri", margin: 0 });
    sl.addText(s.desc, { x: 0.75, y: y + 0.35, w: 9.0, h: 0.32, fontSize: 10, color: C.offwhite, fontFace: "Calibri", margin: 0 });
  });
}

// ══ SLIDE 5 — VASO-OCCLUSION MECHANISM ══════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Vaso-Occlusion — The Multi-Hit Model", "Long Answer — Beyond Simple Polymerisation");
  footerSlide(sl, 5, TOTAL);

  card(sl, 0.2, 1.2, 4.6, 3.7, "Cellular Mechanisms of VOC", [
    "1. Sickled RBC rigidity & adhesion to endothelium",
    "2. Leukocyte (neutrophil) activation & rolling on endothelium",
    "3. Activated vascular endothelium → ↑ VCAM-1, ICAM-1, P-selectin",
    "4. Altered NO metabolism: Hb scavenges NO → vasoconstriction",
    "5. Hypercoagulable state (↑ thrombin generation, microparticles)",
    "6. Ischaemia-reperfusion injury: ROS generation → oxidative stress",
    "7. Inflammatory cytokines: IL-8, IL-1, TNF-α → NF-κB cascade",
    "⚠️ MCQ: VOC involves leukocytes + endothelium + NO + hypercoagulability (NOT hypocoagulability)"
  ], C.accent1);

  if (imgs[0] && imgs[0].base64) {
    sl.addImage({ data: imgs[0].base64, x: 5.0, y: 1.2, w: 4.8, h: 3.7 });
    sl.addText("HbS polymerisation → vaso-occlusion (SEM)", {
      x: 5.0, y: 4.85, w: 4.8, h: 0.25, fontSize: 8, color: C.grey, fontFace: "Calibri", italic: true, align: "center"
    });
  } else {
    card(sl, 5.0, 1.2, 4.8, 3.7, "Precipitating Factors", [
      "Dehydration → ↑ HbS concentration → polymerisation",
      "Hypoxia → deoxygenation → sickling",
      "Acidosis → Bohr effect → O₂ offloading → sickling",
      "Cold exposure → vasoconstriction → stasis",
      "Infection → systemic inflammatory state",
      "Stress / trauma / overexertion"
    ], C.accent3);
  }
}

// ══ SLIDE 6 — HAEMOGLOBIN GENOTYPES TABLE ═══════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Haemoglobin Genotypes & Clinical Severity", "Short Answer / MCQ — Know the Genotypes");
  footerSlide(sl, 6, TOTAL);

  sl.addTable([
    [
      { text: "Genotype", options: { bold: true, color: C.bg, fill: C.accent1, fontSize: 11, fontFace: "Calibri" } },
      { text: "HbS %", options: { bold: true, color: C.bg, fill: C.accent1, fontSize: 11, fontFace: "Calibri" } },
      { text: "Severity", options: { bold: true, color: C.bg, fill: C.accent1, fontSize: 11, fontFace: "Calibri" } },
      { text: "Key Features", options: { bold: true, color: C.bg, fill: C.accent1, fontSize: 11, fontFace: "Calibri" } }
    ],
    [
      { text: "HbSS (Sickle Cell Anaemia)", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } },
      { text: ">85%", options: { color: C.accent1, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Most Severe", options: { color: C.accent1, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Classic disease; all complications", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } }
    ],
    [
      { text: "HbSC", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } },
      { text: "~50% each", options: { color: C.accent2, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Moderate", options: { color: C.accent2, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Retinopathy, avascular necrosis prominent; less anaemia", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } }
    ],
    [
      { text: "HbS-β⁰ thalassaemia", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } },
      { text: ">90%", options: { color: C.accent1, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Severe (like HbSS)", options: { color: C.accent1, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "No HbA produced; clinically = HbSS", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } }
    ],
    [
      { text: "HbS-β⁺ thalassaemia", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } },
      { text: "~70%", options: { color: C.accent2, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Mild-Moderate", options: { color: C.accent2, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Some HbA produced; milder course", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } }
    ],
    [
      { text: "HbAS (Sickle Cell Trait)", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } },
      { text: "~40%", options: { color: C.accent3, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Benign/Carrier", options: { color: C.accent3, bold: true, fontSize: 10, fontFace: "Calibri" } },
      { text: "Usually asymptomatic; haematuria, splenic infarct at altitude", options: { color: C.offwhite, fontSize: 10, fontFace: "Calibri" } }
    ],
  ], {
    x: 0.25, y: 1.25, w: 9.5, h: 3.9,
    rowH: 0.6,
    border: { type: "solid", color: "2C3E50", pt: 1 }
  });

  sl.addText("⭐ MCQ TIP: HbS-β⁰ thal is clinically indistinguishable from HbSS. HbAS trait is usually benign.", {
    x: 0.25, y: 5.18, w: 9.5, h: 0.25,
    fontSize: 9.5, color: C.accent2, bold: true, fontFace: "Calibri", margin: 0
  });
}

// ══ SLIDE 7 — ACUTE CRISES OVERVIEW ═════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Acute Crises in Sickle Cell Disease", "Long Answer — Recognise, Diagnose, Treat");
  footerSlide(sl, 7, TOTAL);

  const crises = [
    { name: "Vaso-Occlusive Crisis (VOC)", col: C.accent1, desc: "Most common; bone/joint/back pain; tissue ischaemia; precipitated by cold, dehydration, infection" },
    { name: "Acute Chest Syndrome (ACS)", col: C.accent1, desc: "New CXR infiltrate + fever/cough/hypoxia/chest pain; leading cause of death; infection, fat embolism, in-situ sickling" },
    { name: "Splenic Sequestration", col: C.accent2, desc: "Sudden trapping of blood in spleen → acute anaemia, ↓ Hb >2g/dL from baseline; massive splenomegaly; haemodynamic collapse; common <5 yrs" },
    { name: "Aplastic Crisis", col: C.accent2, desc: "Parvovirus B19 → transient red cell aplasia; reticulocytopenia; severe anaemia; self-limiting (7-10 days)" },
    { name: "Stroke / CVA", col: C.accent4, desc: "Ischaemic >> haemorrhagic; peak age 2-10 yrs; TCD velocity >200 cm/s = high risk; 11% lifetime risk untreated" },
    { name: "Hyperhemolytic Crisis", col: C.accent3, desc: "Abrupt ↑ haemolysis rate; Hb drops acutely with ↑ reticulocytes; differentiate from aplastic (latter has low reticulocytes)" },
  ];

  crises.forEach((c, i) => {
    const col_ = i % 2, row_ = Math.floor(i / 2);
    const x = 0.2 + col_ * 4.9, y = 1.22 + row_ * 1.38;
    sl.addShape("rect", { x, y, w: 4.7, h: 1.25, fill: { color: C.darkcard }, line: { color: c.col, width: 1.5 } });
    sl.addShape("rect", { x, y, w: 4.7, h: 0.36, fill: { color: c.col } });
    sl.addText(c.name, { x: x + 0.12, y: y + 0.06, w: 4.46, h: 0.28, fontSize: 11.5, bold: true, color: C.white, fontFace: "Calibri", margin: 0 });
    sl.addText(c.desc, { x: x + 0.12, y: y + 0.42, w: 4.46, h: 0.78, fontSize: 9.5, color: C.offwhite, fontFace: "Calibri", valign: "top", margin: 0 });
  });
}

// ══ SLIDE 8 — ACS DETAIL ════════════════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Acute Chest Syndrome (ACS)", "Long Answer — Management Protocol");
  footerSlide(sl, 8, TOTAL);

  card(sl, 0.2, 1.2, 4.6, 4.15, "Definition & Diagnosis", [
    "NEW pulmonary infiltrate on CXR PLUS ≥1 of:",
    "  • Fever (>38.5°C)",
    "  • Respiratory symptoms: cough, wheeze, dyspnoea",
    "  • Chest/rib/bone pain",
    "  • SpO₂ drop from baseline",
    "Most common cause of death in SCD",
    "Occurs in 30% after VOC hospitalisation",
    "Causes: infection (Chlamydia, Mycoplasma, RSV), fat/bone marrow embolism, in-situ sickling, pulmonary infarction",
  ], C.accent1);

  card(sl, 5.05, 1.2, 4.75, 2.0, "Investigations", [
    "CBC + reticulocyte count (baseline Hb essential)",
    "Blood cultures, sputum cultures",
    "CXR — new infiltrate required for diagnosis",
    "ABG if SpO₂ <95% or severe respiratory distress",
    "Cross-match — if transfusion likely",
    "Bronchoalveolar lavage: fat-laden macrophages (fat embolism)"
  ], C.accent2);

  card(sl, 5.05, 3.28, 4.75, 2.07, "Treatment (Mnemonic: OAHATE)", [
    "O — Oxygen (titrate to SpO₂ ≥95%)",
    "A — Analgesics (opioids; incentive spirometry mandatory)",
    "H — Hydration: D5 0.45%NaCl ×1–1.5 maintenance",
    "A — Antibiotics: cover atypicals (azithromycin ± ceftriaxone)",
    "T — Transfusion: simple (Hb <6) or exchange (severe/worsening)",
    "E — Exchange transfusion if: prior ventilation, multiorgan failure, neurological signs, no improvement"
  ], C.accent3);
}

// ══ SLIDE 9 — SPLENIC SEQUESTRATION & APLASTIC ══════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Splenic Sequestration & Aplastic Crisis", "Short Answer / MCQ — Age-Specific Crises");
  footerSlide(sl, 9, TOTAL);

  card(sl, 0.2, 1.22, 4.65, 3.6, "Splenic Sequestration Crisis", [
    "Pathogenesis: Sickled cells pool in splenic sinusoids → sudden ↓ circulating Hb",
    "Definition: Hb falls >2 g/dL from baseline + splenomegaly",
    "Age: Most common <5 years (before autosplenectomy)",
    "Clinical: Lethargy, pallor, LUQ mass/pain, shock, tachycardia",
    "Hb may fall to 1–3 g/dL; haemodynamic collapse possible",
    "Reticulocytes: ELEVATED (distinguishes from aplastic crisis)",
    "Treatment: Urgent IV fluids, simple transfusion (cautious — avoid over-transfusion)",
    "Recurrence: 50% → consider splenectomy",
    "Prevention: Parents taught spleen palpation at home"
  ], C.accent1);

  card(sl, 5.15, 1.22, 4.65, 3.6, "Aplastic Crisis", [
    "Pathogenesis: Parvovirus B19 infects erythroid progenitors → transient arrest of RBC production",
    "Duration: Self-limited 7–10 days (bone marrow recovers)",
    "Clinical: Severe anaemia, fatigue, pallor; fever +/−",
    "KEY DIFFERENTIATOR: Reticulocytes LOW/ABSENT (vs. high in sequestration)",
    "Platelet/WBC count typically preserved initially",
    "Diagnosis: Parvovirus B19 IgM or PCR; bone marrow shows absent erythroblasts",
    "Treatment: RBC transfusion (may require repeated); supportive care",
    "Isolation: Parvovirus B19 infectious — avoid pregnant contacts",
    "⭐ MCQ: Aplastic crisis = Parvo B19 + LOW reticulocytes"
  ], C.accent2);
}

// ══ SLIDE 10 — STROKE & NEUROLOGICAL ════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Cerebrovascular Disease & Stroke", "Long Answer — TCD Screening Protocol");
  footerSlide(sl, 10, TOTAL);

  card(sl, 0.2, 1.22, 4.65, 3.9, "Stroke in SCD", [
    "11% of HbSS children have stroke before age 20 (untreated)",
    "Ischaemic > haemorrhagic (ischaemic in younger children)",
    "Mechanism: Large vessel vasculopathy (internal carotid, MCA) → thrombosis",
    "Moyamoya: 30% of cerebral vasculopathy in paediatric SCD",
    "Presentation: Focal neurological deficit, seizure, altered consciousness",
    "Imaging: MRI + MRA preferred (may also use CT acutely)",
    "Acute treatment: Emergency exchange transfusion (target HbS <30%)",
    "Secondary prevention: Chronic transfusion programme to keep HbS <30%",
    "Hx of stroke → keep HbS <30% lifelong"
  ], C.accent4);

  card(sl, 5.15, 1.22, 4.65, 1.9, "TCD Screening", [
    "Transcranial Doppler from age 2–16 years, annually",
    "Time-averaged mean velocity (TAMV) >200 cm/s = HIGH RISK",
    "TAMV 170–199 cm/s = CONDITIONAL (repeat in 3–6 months)",
    "High risk → prophylactic chronic transfusion reduces stroke risk by 90%",
    "⭐ TCD is a KEY paediatric intervention (STOP trial)"
  ], C.accent3);

  card(sl, 5.15, 3.25, 4.65, 1.9, "Silent Cerebral Infarcts (SCI)", [
    "MRI lesions WITHOUT clinical stroke symptoms",
    "Present in 20–35% of children with HbSS",
    "Associated with cognitive impairment, school difficulties",
    "Diagnosed on MRI brain (routine screening recommended)",
    "Management: hydroxyurea; consider transfusion if progressive"
  ], C.accent2);
}

// ══ SLIDE 11 — CHRONIC COMPLICATIONS ════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Chronic Organ Complications", "Long Answer — Systematic Review");
  footerSlide(sl, 11, TOTAL);

  const organs = [
    { organ: "Spleen", col: C.accent1, points: ["Autosplenectomy by age 5–8 years (repeated infarction)", "Functional asplenia → encapsulated organisms (Strep pneumo, H. influenzae, Neisseria)", "↑ Risk: sepsis, meningitis"] },
    { organ: "Lung", col: C.accent2, points: ["Recurrent ACS → restrictive lung disease", "Pulmonary hypertension (TRV >2.5 m/s)", "SpO₂ monitoring; annual echo for PH screening"] },
    { organ: "Brain", col: C.accent4, points: ["Overt stroke (11%), Silent cerebral infarcts (20–35%)", "Cognitive impairment, learning disabilities", "Moyamoya syndrome"] },
    { organ: "Bone", col: C.accent3, points: ["Avascular necrosis: femoral/humeral heads", "Dactylitis (hand-foot syndrome) — first crisis in infants", "Osteomyelitis (Salmonella, Staph aureus)"] },
    { organ: "Kidney", col: C.accent2, points: ["Sickle nephropathy: papillary necrosis, proteinuria, haematuria", "Hyposthenuria (inability to concentrate urine) — early sign", "CKD in adults; glomerulosclerosis"] },
    { organ: "Eye", col: C.accent3, points: ["Proliferative retinopathy (especially HbSC)", "Annual ophthalmology screening", "Can cause retinal detachment and blindness"] },
  ];

  organs.forEach((o, i) => {
    const col_ = i % 3, row_ = Math.floor(i / 3);
    const x = 0.2 + col_ * 3.25, y = 1.22 + row_ * 2.05;
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    sl.addShape("rect", { x, y, w: 3.1, h: 0.35, fill: { color: o.col } });
    sl.addText(o.organ, { x: x + 0.1, y: y + 0.06, w: 2.9, h: 0.26, fontSize: 12, bold: true, color: C.white, fontFace: "Calibri", margin: 0 });
    const items = o.points.map((p, pi) => ({
      text: p, options: { bullet: { type: "bullet" }, color: C.offwhite, fontSize: 9, fontFace: "Calibri", breakLine: pi < o.points.length - 1 }
    }));
    sl.addText(items, { x: x + 0.08, y: y + 0.4, w: 2.94, h: 1.42, valign: "top", margin: 0 });
  });
}

// ══ SLIDE 12 — DIAGNOSIS ════════════════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Diagnosis & Laboratory Findings", "Short Answer — Know Your Lab Values");
  footerSlide(sl, 12, TOTAL);

  card(sl, 0.2, 1.22, 4.65, 4.1, "Neonatal Screening & Confirmatory Tests", [
    "Neonatal screening: Haemoglobin ELECTROPHORESIS (HPLC) — gold standard",
    "Pattern HbSS: FS (Fetal + Sickle bands; no A band)",
    "Pattern HbSC: FSC",
    "Pattern HbAS (trait): FAS",
    "Confirmatory: repeat electrophoresis at 3–6 months",
    "Sickling test (Sickledex/sodium metabisulfite): cheap screening but does NOT distinguish SS from AS",
    "MRI brain: silent cerebral infarcts",
    "TCD ultrasonography: stroke risk stratification",
    "Echo: pulmonary hypertension screening",
    "Urine: haematuria, hyposthenuria (inability to concentrate)",
  ], C.accent4);

  card(sl, 5.15, 1.22, 4.65, 2.0, "Peripheral Blood Film", [
    "Sickle cells (drepanocytes) — crescent/boat shapes",
    "Target cells (HbSC, S-thal)",
    "Polychromasia — ↑ reticulocytes (compensatory haematopoiesis)",
    "Howell-Jolly bodies — evidence of functional asplenia",
    "Nucleated RBCs in severe anaemia",
    "⭐ Howell-Jolly bodies = functional asplenia (MCQ favourite)"
  ], C.accent2);

  card(sl, 5.15, 3.28, 4.65, 2.1, "Routine Labs in SCD", [
    "Hb: 6–9 g/dL (baseline in HbSS)",
    "MCV: Normal or mildly ↓ (macrocytosis if on hydroxyurea)",
    "WBC: Elevated (leukocytosis common — marker of inflammation)",
    "Reticulocytes: 5–15% (elevated baseline)",
    "Bilirubin: ↑ unconjugated (haemolysis)",
    "LDH: ↑ (marker of haemolysis intensity)",
    "Urinalysis: haematuria, proteinuria, low SG"
  ], C.accent3);
}

// ══ SLIDE 13 — MANAGEMENT OVERVIEW ═════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Management — Comprehensive Overview", "Long Answer — Acute + Chronic + Curative");
  footerSlide(sl, 13, TOTAL);

  card(sl, 0.2, 1.22, 3.05, 4.1, "Acute VOC Management", [
    "Hydration: oral preferred; IV D5 0.45% NS ×1–1.5 maintenance",
    "Analgesia: WHO ladder",
    "  • Mild: paracetamol + NSAID (ketorolac)",
    "  • Moderate-Severe: opioids (morphine)",
    "  • PCA morphine for inpatients",
    "Oxygen ONLY if SpO₂ <95%",
    "Incentive spirometry (prevents ACS)",
    "Treat precipitating infection",
    "Avoid over-hydration (risk of ACS)",
    "Monitor resp rate hourly on opioids"
  ], C.accent1);

  card(sl, 3.5, 1.22, 3.05, 4.1, "Hydroxyurea (HU)", [
    "Mechanism: ↑ HbF → inhibits HbS polymerisation",
    "Also: ↓ leukocytes, ↓ RBC adhesion, ↑ RBC hydration",
    "Indications (paeds): ≥9 months all HbSS/HbS-β⁰thal (2014 ASH)",
    "BABY HUG trial: HU in infants → ↓ VOC, ACS, dactylitis",
    "Dose: 20 mg/kg/day, titrate to response (max ~35 mg/kg)",
    "Monitor: CBC every 2–4 weeks initially (myelosuppression)",
    "Side effects: neutropenia, thrombocytopenia, teratogenic",
    "⭐ HU is disease-modifying — reduces mortality"
  ], C.accent3);

  card(sl, 6.8, 1.22, 3.0, 4.1, "Transfusion Therapy", [
    "Simple transfusion: ACS, splenic sequestration, aplastic crisis, preoperative",
    "Chronic transfusion: stroke prevention (TCD >200 cm/s), recurrent ACS",
    "Target: Hb ≤10 g/dL; HbS <30%",
    "Exchange transfusion: acute stroke, severe ACS, multiorgan failure",
    "Complications: alloimmunisation, iron overload (treat with deferasirox), transfusion reactions, infections",
    "Iron chelation: deferasirox (oral) or desferrioxamine (SC) when ferritin >1000",
    "Asymptomatic: do NOT transfuse for Hb level alone"
  ], C.accent2);
}

// ══ SLIDE 14 — PREVENTION & PROPHYLAXIS ══════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Prevention, Prophylaxis & Long-Term Care", "Short Answer — Paediatric Surveillance");
  footerSlide(sl, 14, TOTAL);

  card(sl, 0.2, 1.22, 4.65, 1.72, "Antibiotic Prophylaxis", [
    "Penicillin V: start at 2–3 months (before spleen dysfunction complete)",
    "Dose: 125 mg BD (<3 yrs), 250 mg BD (≥3 yrs)",
    "Continue until at least age 5 years",
    "Penicillin-allergic: erythromycin",
    "⭐ Prevents pneumococcal septicaemia — most important early intervention"
  ], C.accent1);

  card(sl, 0.2, 3.0, 4.65, 2.3, "Vaccination Schedule", [
    "Pneumococcal: PCV-13 (routine childhood) + PPSV-23 (from age 2)",
    "Haemophilus influenzae type b (Hib)",
    "Meningococcal: MenACWY + MenB",
    "Annual influenza vaccine",
    "Hepatitis B (blood product exposure)",
    "⭐ MCQ: Vaccinate against ENCAPSULATED organisms (Pneumococcus, Hib, Meningococcus)"
  ], C.accent2);

  card(sl, 5.15, 1.22, 4.65, 1.72, "TCD & Stroke Prevention", [
    "TCD screening: Annual from age 2–16 years",
    "High risk (>200 cm/s) → chronic transfusion reduces stroke by 90%",
    "Conditional (170–199) → repeat in 3–6 months",
    "STOP & STOP 2 trials established TCD-based protocol",
    "Hydroxyurea now shown non-inferior to transfusion (TWiTCH trial)"
  ], C.accent4);

  card(sl, 5.15, 3.0, 4.65, 2.3, "Curative & Novel Therapies", [
    "HSCT (Haematopoietic Stem Cell Transplant): only current CURE",
    "Requires HLA-matched sibling donor; survival >90%",
    "Gene therapy: lentiviral HbF-inducing vectors (FDA-approved 2023: Casgevy — CRISPR)",
    "Voxelotor: HbS anti-polymerisation agent (increases O₂ affinity)",
    "Crizanlizumab: anti-P-selectin antibody (reduces VOC frequency)",
    "L-glutamine: reduces oxidative stress; FDA-approved supplement"
  ], C.accent3);
}

// ══ SLIDE 15 — DACTYLITIS & INFECTION ════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Dactylitis, Infection & Osteomyelitis", "Short Answer / MCQ — Infant Presentations");
  footerSlide(sl, 15, TOTAL);

  card(sl, 0.2, 1.22, 4.65, 3.8, "Dactylitis (Hand-Foot Syndrome)", [
    "FIRST clinical manifestation of SCD in infants (age 6–24 months)",
    "Cause: Vaso-occlusion in small bones of hands/feet → infarction",
    "Presentation: Painful, non-pitting swelling of hands/feet; fever",
    "Bilateral and symmetric common",
    "Resolves spontaneously in 1–2 weeks",
    "Differential: osteomyelitis (persistent fever, elevated WBC, CRP)",
    "Treatment: analgesia, hydration, treat fever",
    "⭐ Dactylitis = first crisis in infant → always test for SCD in infant with hand/foot swelling + fever",
    "Radiograph: normal initially; periosteal reaction later"
  ], C.accent2);

  card(sl, 5.15, 1.22, 4.65, 3.8, "Infection & Sepsis", [
    "Functional asplenia → encapsulated organism susceptibility",
    "Most feared: Streptococcus pneumoniae septicaemia (can be fulminant)",
    "Also: Haemophilus influenzae, Neisseria meningitidis, Salmonella",
    "FEVER in SCD child: MEDICAL EMERGENCY until proven otherwise",
    "  • Temp ≥38.5°C → blood culture + empiric IV antibiotics",
    "  • Ceftriaxone (covers pneumococcus + Gram-negatives)",
    "Osteomyelitis: Salmonella spp. (most specific to SCD), Staph aureus",
    "Differentiate AVN from osteomyelitis: MRI, bone scan, WBC, CRP",
    "⭐ MCQ: Salmonella osteomyelitis = pathognomonic association with SCD"
  ], C.accent1);
}

// ══ SLIDE 16 — MCQ BANK ══════════════════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "MCQ Bank — High-Yield Questions", "Exam Drill — Cover the answers first!");
  footerSlide(sl, 16, TOTAL);

  const mcqs = [
    { q: "Q1. Molecular basis of HbS?", a: "A. Glu→Val substitution at β-globin position 6", col: C.accent1 },
    { q: "Q2. First crisis in infant with SCD?", a: "A. Dactylitis (hand-foot syndrome)", col: C.accent2 },
    { q: "Q3. Aplastic crisis pathogen?", a: "A. Parvovirus B19 (low/absent reticulocytes)", col: C.accent3 },
    { q: "Q4. TCD cut-off for stroke high-risk?", a: "A. ≥200 cm/s TAMV → start chronic transfusion", col: C.accent4 },
    { q: "Q5. Most specific osteomyelitis organism in SCD?", a: "A. Salmonella spp.", col: C.accent1 },
    { q: "Q6. Blood film finding of functional asplenia?", a: "A. Howell-Jolly bodies", col: C.accent2 },
    { q: "Q7. Mechanism of hydroxyurea?", a: "A. ↑ HbF production → inhibits HbS polymerisation", col: C.accent3 },
    { q: "Q8. Key differentiator: splenic sequestration vs aplastic?", a: "A. Sequestration: HIGH reticulocytes; Aplastic: LOW reticulocytes", col: C.accent4 },
  ];

  mcqs.forEach((m, i) => {
    const col_ = i % 2, row_ = Math.floor(i / 2);
    const x = 0.2 + col_ * 4.9, y = 1.22 + row_ * 1.04;
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    sl.addText(m.q, { x: x + 0.12, y: y + 0.07, w: 4.46, h: 0.3, fontSize: 10.5, bold: true, color: m.col, fontFace: "Calibri", margin: 0 });
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}

// ══ SLIDE 17 — SHORT ANSWER KEYS ════════════════════════════════════════════
{
  const sl = pres.addSlide(); bgFill(sl);
  hdr(sl, "Short Answer Key Points", "Quick-Recall Summary for SAQ Questions");
  footerSlide(sl, 17, TOTAL);

  card(sl, 0.2, 1.22, 4.65, 4.15, "Pathophysiology SAQ", [
    "1. β-globin point mutation: adenine→thymine → Glu→Val (position 6)",
    "2. Deoxygenation triggers HbS polymerisation into rigid fibres",
    "3. Sickled RBC lifespan: ~20 days (normal: 120 days) → haemolytic anaemia",
    "4. VOC involves: sickled RBCs + leukocytes + endothelium + ↓NO + hypercoagulability",
    "5. HbF is protective — no β-globin chains, does not sickle",
    "6. Autosplenectomy by age 5–8: repeated splenic infarction → functional asplenia",
    "7. Free Hb from haemolysis scavenges NO → ↑ vasoconstriction, platelet aggregation",
    "8. Ischaemia-reperfusion injury → reactive oxygen species → endothelial damage"
  ], C.accent1);

  card(sl, 5.15, 1.22, 4.65, 4.15, "Clinical & Management SAQ", [
    "1. Neonatal screening: HPLC/Hb electrophoresis — FS pattern = HbSS",
    "2. Penicillin prophylaxis from 2–3 months of age, continue to age 5+",
    "3. Fever in SCD = emergency: blood culture + IV ceftriaxone stat",
    "4. VOC management: analgesia (opioids) + hydration + treat precipitant",
    "5. ACS treatment: O₂, antibiotics, incentive spirometry, +/− transfusion",
    "6. Hydroxyurea: ↑ HbF — 1st-line disease-modifying therapy",
    "7. Transfusion target: Hb ≤10 g/dL, HbS <30%",
    "8. Curative: HLA-matched sibling HSCT; gene therapy (Casgevy/CRISPR)",
    "9. TCD >200 cm/s → 90% stroke reduction with chronic transfusion programme"
  ], C.accent3);
}

// ══ SLIDE 18 — SUMMARY ═══════════════════════════════════════════════════════
{
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    fontSize: 24, bold: true, color: C.white, fontFace: "Calibri", charSpacing: 2, margin: 0
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  const facts = [
    ["1", "Mutation: Glu→Val at β-globin position 6 (adenine→thymine DNA substitution)", C.accent1],
    ["2", "HbF is protective; symptoms begin as HbF falls after 6 months of age", C.accent2],
    ["3", "Autosplenectomy by age 5 → encapsulated organisms → penicillin prophylaxis + vaccines", C.accent1],
    ["4", "Dactylitis = FIRST crisis in infants (6–24 months); Parvovirus B19 = aplastic crisis", C.accent2],
    ["5", "Aplastic crisis: LOW reticulocytes; Splenic sequestration: HIGH reticulocytes", C.accent3],
    ["6", "ACS: NEW CXR infiltrate + fever/resp symptoms = most common cause of death", C.accent4],
    ["7", "TCD >200 cm/s → high stroke risk → chronic transfusion → 90% stroke reduction", C.accent4],
    ["8", "Hydroxyurea: ↑ HbF; BABY HUG trial → recommend from 9 months in all HbSS", C.accent3],
    ["9", "Howell-Jolly bodies = functional asplenia; Salmonella osteomyelitis = SCD-specific", C.accent2],
    ["10","VOC: multi-hit model (sickled RBCs + leukocytes + ↓NO + hypercoag + ischaemia-reperfusion)", C.accent1],
  ];

  facts.forEach(([num, text, col], i) => {
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  });

  footerSlide(sl, 18, TOTAL);
}

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