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

// ─── Fetch images as base64 ───────────────────────────────────────────────────
const IMAGE_URLS = [
  "https://microbenotes.com/wp-content/uploads/2019/10/Parts-of-Colorimeter.jpg",
  "https://laboratorytests.org/wp-content/uploads/2022/08/Colorimeter-principle-instrumentation-scaled.jpg",
  "https://cdn1.byjus.com/wp-content/uploads/2022/02/colorimeter-instrument.png",
  "https://laboratorytests.org/wp-content/uploads/2022/08/Colorimeter-scaled.jpg",
  "https://microbenotes.com/wp-content/uploads/2019/10/Colorimeter.jpg"
];

console.log("Fetching images...");
let images = [];
try {
  const raw = execSync(
    `node /home/daytona/skills/shared/scripts/fetch_images.js ${IMAGE_URLS.map(u => `"${u}"`).join(" ")}`,
    { maxBuffer: 100 * 1024 * 1024 }
  ).toString();
  images = JSON.parse(raw);
  images.forEach((img, i) => {
    if (img.error) console.warn(`  [WARN] Image ${i} failed: ${img.error}`);
    else console.log(`  [OK] Image ${i}: ${img.url.split("/").pop()}`);
  });
} catch (e) {
  console.error("Image fetch error:", e.message);
}

// helper: return base64 data or null
function img(index) {
  if (!images[index] || images[index].error) return null;
  return images[index].base64;
}

// ─── Theme constants ──────────────────────────────────────────────────────────
const BG_DARK    = "0D1B4B";   // deep navy
const BG_MID     = "0F2167";   // slightly lighter navy
const BG_CARD    = "162458";   // card background
const GOLD       = "F5A623";   // amber/gold accent
const GOLD_LIGHT = "FFD580";   // light gold
const WHITE      = "FFFFFF";
const LIGHT_BLUE = "90CAF9";
const TEAL       = "26C6DA";
const GREEN      = "66BB6A";
const RED_SOFT   = "EF5350";
const SLIDE_W    = 13.3;
const SLIDE_H    = 7.5;

// ─── Slide helpers ────────────────────────────────────────────────────────────

// Full-slide dark navy background
function addBg(slide, color = BG_DARK) {
  slide.addShape("rect", { x: 0, y: 0, w: SLIDE_W, h: SLIDE_H, fill: { color } });
}

// Top accent bar
function addTopBar(slide, accentColor = GOLD) {
  slide.addShape("rect", { x: 0, y: 0, w: SLIDE_W, h: 0.08, fill: { color: accentColor } });
}

// Bottom accent bar
function addBottomBar(slide, accentColor = GOLD) {
  slide.addShape("rect", { x: 0, y: SLIDE_H - 0.08, w: SLIDE_W, h: 0.08, fill: { color: accentColor } });
}

// Section title strip
function addTitleStrip(slide, title, y = 0.28, bgColor = BG_MID, textColor = GOLD) {
  slide.addShape("rect", { x: 0, y, w: SLIDE_W, h: 0.72, fill: { color: bgColor } });
  slide.addText(title, {
    x: 0.4, y, w: SLIDE_W - 0.8, h: 0.72,
    fontSize: 22, bold: true, color: textColor,
    fontFace: "Calibri", valign: "middle", margin: 0
  });
}

// Decorative side strip
function addSideStrip(slide, x, color = GOLD, opacity = 0.3) {
  slide.addShape("rect", { x, y: 0, w: 0.06, h: SLIDE_H, fill: { color, transparency: Math.round(opacity * 100) } });
}

// Small dot decorations (top-right corner)
function addCornerDots(slide) {
  const positions = [[12.7, 0.3], [12.9, 0.5], [12.5, 0.55]];
  positions.forEach(([cx, cy]) => {
    slide.addShape("ellipse", { x: cx, y: cy, w: 0.15, h: 0.15, fill: { color: GOLD, transparency: 60 } });
  });
}

// Card / info box
function addCard(slide, x, y, w, h, fillColor = BG_CARD, borderColor = GOLD) {
  slide.addShape("rect", {
    x, y, w, h,
    fill: { color: fillColor },
    line: { color: borderColor, width: 1 }
  });
}

// Slide number
function addSlideNum(slide, num, total) {
  slide.addText(`${num} / ${total}`, {
    x: SLIDE_W - 1.2, y: SLIDE_H - 0.38, w: 1.0, h: 0.3,
    fontSize: 9, color: GOLD_LIGHT, align: "right", fontFace: "Calibri", margin: 0
  });
}

// ─── Create Presentation ─────────────────────────────────────────────────────
const pres = new pptxgen();
pres.layout = "LAYOUT_WIDE";
pres.title  = "Colorimeter";
pres.author = "Generated by Orris";

const TOTAL = 10;

// ════════════════════════════════════════════════════════════
// SLIDE 1 – Title slide
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s, BG_DARK);

  // Bold gold vertical stripe left
  s.addShape("rect", { x: 0, y: 0, w: 0.45, h: SLIDE_H, fill: { color: GOLD } });

  // Diagonal accent shape
  s.addShape("rect", {
    x: 0.45, y: 0, w: 0.25, h: SLIDE_H,
    fill: { color: GOLD_LIGHT, transparency: 60 }
  });

  // Right image panel
  const imgData = img(2);
  if (imgData) {
    s.addImage({ data: imgData, x: 7.8, y: 1.0, w: 5.0, h: 5.0 });
    // overlay tint over image
    s.addShape("rect", { x: 7.8, y: 1.0, w: 5.0, h: 5.0, fill: { color: BG_DARK, transparency: 40 } });
  }

  // Main title
  s.addText("COLORIMETER", {
    x: 0.9, y: 1.6, w: 7.0, h: 1.2,
    fontSize: 54, bold: true, color: WHITE,
    fontFace: "Calibri", charSpacing: 8, margin: 0
  });

  // Gold underline bar
  s.addShape("rect", { x: 0.9, y: 2.9, w: 5.5, h: 0.06, fill: { color: GOLD } });

  // Subtitle
  s.addText("Principle, Components & Clinical Applications", {
    x: 0.9, y: 3.1, w: 7.0, h: 0.6,
    fontSize: 18, color: GOLD_LIGHT, italic: true,
    fontFace: "Calibri", margin: 0
  });

  // Tag line
  s.addText("A fundamental tool in clinical biochemistry", {
    x: 0.9, y: 3.85, w: 7.0, h: 0.4,
    fontSize: 13, color: LIGHT_BLUE, fontFace: "Calibri", margin: 0
  });

  // Bottom ribbon
  s.addShape("rect", { x: 0, y: SLIDE_H - 0.7, w: SLIDE_W, h: 0.7, fill: { color: BG_MID } });
  s.addText("Clinical Biochemistry  |  Analytical Instruments", {
    x: 0.9, y: SLIDE_H - 0.65, w: 9, h: 0.6,
    fontSize: 11, color: GOLD_LIGHT, fontFace: "Calibri", valign: "middle", margin: 0
  });

  addSlideNum(s, 1, TOTAL);
}

// ════════════════════════════════════════════════════════════
// SLIDE 2 – Introduction & History
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "Introduction & History", 0.25);
  addSlideNum(s, 2, TOTAL);

  // Definition card
  addCard(s, 0.5, 1.15, 8.0, 1.15);
  s.addText([
    { text: "COLORIMETER", options: { bold: true, color: GOLD } },
    { text: "  — An instrument that measures the ", options: { color: WHITE } },
    { text: "absorbance", options: { bold: true, color: TEAL } },
    { text: " or ", options: { color: WHITE } },
    { text: "transmittance", options: { bold: true, color: TEAL } },
    { text: " of light through a colored solution to determine its ", options: { color: WHITE } },
    { text: "concentration.", options: { bold: true, color: GOLD_LIGHT } }
  ], { x: 0.65, y: 1.2, w: 7.7, h: 1.05, fontSize: 15, fontFace: "Calibri", valign: "middle" });

  // Timeline
  const timeline = [
    { year: "1728", name: "Johann Heinrich Lambert", fact: "Described how absorbance is proportional to path length (Lambert's Law)", color: TEAL },
    { year: "1825", name: "August Beer", fact: "Showed absorbance is proportional to concentration (Beer's Law)", color: GREEN },
    { year: "1852", name: "Beer-Lambert Law", fact: "Combined law: A = εcl — foundation of colorimetry", color: GOLD }
  ];

  timeline.forEach((item, i) => {
    const yy = 2.5 + i * 1.45;
    // connector dot
    s.addShape("ellipse", { x: 0.55, y: yy + 0.25, w: 0.3, h: 0.3, fill: { color: item.color } });
    // line
    if (i < 2) s.addShape("rect", { x: 0.67, y: yy + 0.55, w: 0.06, h: 0.9, fill: { color: item.color, transparency: 50 } });
    // year badge
    addCard(s, 1.0, yy, 1.0, 0.5, item.color, item.color);
    s.addText(item.year, { x: 1.0, y: yy, w: 1.0, h: 0.5, fontSize: 13, bold: true, color: BG_DARK, align: "center", valign: "middle", margin: 0 });
    // content
    s.addText(item.name, { x: 2.2, y: yy + 0.0, w: 8.5, h: 0.28, fontSize: 13, bold: true, color: WHITE, fontFace: "Calibri", margin: 0 });
    s.addText(item.fact, { x: 2.2, y: yy + 0.28, w: 8.5, h: 0.28, fontSize: 11, color: LIGHT_BLUE, fontFace: "Calibri", italic: true, margin: 0 });
  });
}

// ════════════════════════════════════════════════════════════
// SLIDE 3 – Beer-Lambert Law (Principle)
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "Principle: Beer-Lambert Law", 0.25);
  addSlideNum(s, 3, TOTAL);

  // Law formula box – centered
  addCard(s, 2.2, 1.15, 8.9, 1.1, "102040", GOLD);
  s.addText("A = ε × c × l", {
    x: 2.2, y: 1.15, w: 8.9, h: 1.1,
    fontSize: 38, bold: true, color: GOLD, align: "center", valign: "middle",
    fontFace: "Courier New", margin: 0
  });

  // Legend
  const legend = [
    { sym: "A",   desc: "Absorbance (dimensionless)",      color: GOLD },
    { sym: "ε",   desc: "Molar absorptivity (L·mol⁻¹·cm⁻¹)", color: TEAL },
    { sym: "c",   desc: "Concentration (mol/L)",           color: GREEN },
    { sym: "l",   desc: "Path length (cm) — fixed by cuvette", color: LIGHT_BLUE }
  ];
  legend.forEach((item, i) => {
    const xx = 0.5 + (i % 2) * 6.4;
    const yy = 2.55 + Math.floor(i / 2) * 0.75;
    addCard(s, xx, yy, 6.0, 0.6, BG_CARD, item.color);
    s.addText(item.sym, { x: xx + 0.1, y: yy, w: 0.5, h: 0.6, fontSize: 20, bold: true, color: item.color, align: "center", valign: "middle", fontFace: "Courier New", margin: 0 });
    s.addText(item.desc, { x: xx + 0.7, y: yy, w: 5.1, h: 0.6, fontSize: 13, color: WHITE, valign: "middle", fontFace: "Calibri", margin: 0 });
  });

  // Two laws boxes
  const laws = [
    { title: "Beer's Law", text: "Absorbance is DIRECTLY proportional to the CONCENTRATION of the solution\n(A ∝ c)", color: TEAL },
    { title: "Lambert's Law", text: "Absorbance is DIRECTLY proportional to the PATH LENGTH of the solution\n(A ∝ l)", color: GREEN }
  ];
  laws.forEach((law, i) => {
    const xx = 0.5 + i * 6.4;
    addCard(s, xx, 4.25, 6.2, 2.9, BG_CARD, law.color);
    s.addShape("rect", { x: xx, y: 4.25, w: 6.2, h: 0.45, fill: { color: law.color } });
    s.addText(law.title, { x: xx + 0.1, y: 4.25, w: 6.0, h: 0.45, fontSize: 14, bold: true, color: BG_DARK, align: "center", valign: "middle", margin: 0 });
    s.addText(law.text, { x: xx + 0.2, y: 4.75, w: 5.8, h: 2.3, fontSize: 13, color: WHITE, fontFace: "Calibri", valign: "middle" });
  });
}

// ════════════════════════════════════════════════════════════
// SLIDE 4 – Components / Parts
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "Components of a Colorimeter", 0.25);
  addSlideNum(s, 4, TOTAL);

  const partsImg = img(0);
  if (partsImg) {
    s.addImage({ data: partsImg, x: 7.1, y: 1.15, w: 5.9, h: 6.0 });
    s.addShape("rect", { x: 7.1, y: 1.15, w: 5.9, h: 6.0, fill: { color: BG_DARK, transparency: 20 } });
  }

  const parts = [
    { n: "01", name: "Light Source", desc: "Tungsten lamp (400–760 nm visible range)", color: GOLD },
    { n: "02", name: "Adjustable Slit", desc: "Controls beam width entering the system", color: TEAL },
    { n: "03", name: "Condensing Lens", desc: "Focuses light into a parallel beam", color: GREEN },
    { n: "04", name: "Color Filter", desc: "Selects wavelength complementary to solution color", color: LIGHT_BLUE },
    { n: "05", name: "Cuvette / Sample Holder", desc: "Fixed diameter; quartz for UV range measurements", color: RED_SOFT },
    { n: "06", name: "Photodetector", desc: "Photocell converts transmitted light to electrical signal", color: "CE93D8" },
    { n: "07", name: "Display / Galvanometer", desc: "Shows absorbance or % transmittance value", color: GOLD_LIGHT }
  ];

  parts.forEach((p, i) => {
    const yy = 1.2 + i * 0.82;
    s.addShape("ellipse", { x: 0.45, y: yy + 0.1, w: 0.4, h: 0.4, fill: { color: p.color } });
    s.addText(p.n, { x: 0.45, y: yy + 0.1, w: 0.4, h: 0.4, fontSize: 9, bold: true, color: BG_DARK, align: "center", valign: "middle", margin: 0 });
    s.addText(p.name, { x: 1.0, y: yy, w: 5.9, h: 0.28, fontSize: 13, bold: true, color: p.color, fontFace: "Calibri", margin: 0 });
    s.addText(p.desc, { x: 1.0, y: yy + 0.28, w: 5.9, h: 0.28, fontSize: 11, color: LIGHT_BLUE, fontFace: "Calibri", italic: true, margin: 0 });
  });
}

// ════════════════════════════════════════════════════════════
// SLIDE 5 – How it Works (Operation)
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "How a Colorimeter Works", 0.25);
  addSlideNum(s, 5, TOTAL);

  // Diagram image
  const diaImg = img(1);
  if (diaImg) {
    s.addImage({ data: diaImg, x: 0.5, y: 1.1, w: 5.5, h: 3.3 });
  }

  // Flow steps on right
  const steps = [
    { n: 1, text: "Tungsten lamp emits white light (400–760 nm)", color: GOLD },
    { n: 2, text: "Slit narrows beam; lens collimates it", color: TEAL },
    { n: 3, text: "Color filter isolates desired wavelength", color: GREEN },
    { n: 4, text: "Monochromatic beam passes through cuvette", color: LIGHT_BLUE },
    { n: 5, text: "Colored solution absorbs part of the light", color: RED_SOFT },
    { n: 6, text: "Transmitted light hits photocell (detector)", color: "CE93D8" },
    { n: 7, text: "Electrical signal displayed as A or %T", color: GOLD_LIGHT }
  ];

  steps.forEach((st, i) => {
    const yy = 1.15 + i * 0.85;
    addCard(s, 6.3, yy, 6.6, 0.72, BG_CARD, st.color);
    s.addShape("ellipse", { x: 6.35, y: yy + 0.18, w: 0.36, h: 0.36, fill: { color: st.color } });
    s.addText(String(st.n), { x: 6.35, y: yy + 0.18, w: 0.36, h: 0.36, fontSize: 11, bold: true, color: BG_DARK, align: "center", valign: "middle", margin: 0 });
    s.addText(st.text, { x: 6.85, y: yy, w: 5.9, h: 0.72, fontSize: 12, color: WHITE, fontFace: "Calibri", valign: "middle" });
  });

  // Formula label below image
  addCard(s, 0.5, 4.6, 5.5, 1.2, "102040", GOLD);
  s.addText("Key Formula:", { x: 0.65, y: 4.65, w: 5.1, h: 0.35, fontSize: 12, bold: true, color: GOLD, fontFace: "Calibri", margin: 0 });
  s.addText("C(unknown)  =  (OD Test − OD Blank)  ×  C(standard)\n               (OD Standard − OD Blank)", {
    x: 0.65, y: 5.0, w: 5.3, h: 0.75, fontSize: 10.5, color: WHITE, fontFace: "Courier New"
  });
}

// ════════════════════════════════════════════════════════════
// SLIDE 6 – Cuvette Details
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "Cuvette — Sample Holder", 0.25);
  addSlideNum(s, 6, TOTAL);

  const cuvImg = img(4);
  if (cuvImg) {
    s.addImage({ data: cuvImg, x: 8.5, y: 1.2, w: 4.3, h: 5.8 });
    s.addShape("rect", { x: 8.5, y: 1.2, w: 4.3, h: 5.8, fill: { color: BG_DARK, transparency: 30 } });
  }

  const props = [
    { label: "Shape", value: "Usually rectangular or cylindrical", color: GOLD },
    { label: "Diameter", value: "Fixed — ensures constant path length (l)", color: TEAL },
    { label: "Material (Visible)", value: "Borosilicate glass or plastic", color: GREEN },
    { label: "Material (UV range)", value: "Quartz (transparent to UV light)", color: LIGHT_BLUE },
    { label: "Volume", value: "Typically 1–4 mL capacity", color: RED_SOFT },
    { label: "Cleaning", value: "Must be spotless — smudges cause error", color: "CE93D8" }
  ];

  props.forEach((p, i) => {
    const yy = 1.25 + i * 0.95;
    addCard(s, 0.5, yy, 7.8, 0.82, BG_CARD, p.color);
    s.addShape("rect", { x: 0.5, y: yy, w: 1.8, h: 0.82, fill: { color: p.color } });
    s.addText(p.label, { x: 0.5, y: yy, w: 1.8, h: 0.82, fontSize: 12, bold: true, color: BG_DARK, align: "center", valign: "middle", margin: 0 });
    s.addText(p.value, { x: 2.45, y: yy, w: 5.7, h: 0.82, fontSize: 13, color: WHITE, fontFace: "Calibri", valign: "middle" });
  });

  // Note
  addCard(s, 0.5, 7.0, 7.8, 0.35, "102040", GOLD);
  s.addText("Note: The blank/reagent blank is always measured first to zero out background absorption.", {
    x: 0.6, y: 7.0, w: 7.6, h: 0.35, fontSize: 10.5, color: GOLD_LIGHT, fontFace: "Calibri", italic: true, valign: "middle"
  });
}

// ════════════════════════════════════════════════════════════
// SLIDE 7 – Types of Analysis
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "Types of Colorimetric Analysis", 0.25);
  addSlideNum(s, 7, TOTAL);

  // End-point card
  addCard(s, 0.5, 1.15, 5.9, 5.7, BG_CARD, TEAL);
  s.addShape("rect", { x: 0.5, y: 1.15, w: 5.9, h: 0.52, fill: { color: TEAL } });
  s.addText("1. End-Point Analysis", { x: 0.6, y: 1.15, w: 5.7, h: 0.52, fontSize: 15, bold: true, color: BG_DARK, valign: "middle", margin: 0 });

  const epPoints = [
    "Reaction allowed to go to COMPLETION before reading",
    "Incubation at 37°C for 10 minutes",
    "Single absorbance reading taken",
    "Used for: Glucose, Urea, Creatinine, Bilirubin, Proteins",
    "Simple, fast, widely used in clinical labs",
    "Result compared to blank and standard"
  ];
  epPoints.forEach((pt, i) => {
    s.addText([
      { text: "• ", options: { color: TEAL, bold: true } },
      { text: pt, options: { color: WHITE } }
    ], { x: 0.7, y: 1.75 + i * 0.73, w: 5.5, h: 0.65, fontSize: 12, fontFace: "Calibri", valign: "middle" });
  });

  // Kinetic card
  addCard(s, 6.9, 1.15, 5.9, 5.7, BG_CARD, GREEN);
  s.addShape("rect", { x: 6.9, y: 1.15, w: 5.9, h: 0.52, fill: { color: GREEN } });
  s.addText("2. Kinetic Analysis", { x: 7.0, y: 1.15, w: 5.7, h: 0.52, fontSize: 15, bold: true, color: BG_DARK, valign: "middle", margin: 0 });

  const kinPoints = [
    "Measures RATE of change in absorbance over time",
    "Readings taken at 2 and 3 minutes after mixing",
    "Delta OD (ΔOD) per minute is calculated",
    "Used for: Enzymes — AST/SGOT, ALT/SGPT",
    "Reflects enzyme catalytic activity directly",
    "More sensitive to reaction dynamics"
  ];
  kinPoints.forEach((pt, i) => {
    s.addText([
      { text: "• ", options: { color: GREEN, bold: true } },
      { text: pt, options: { color: WHITE } }
    ], { x: 7.1, y: 1.75 + i * 0.73, w: 5.5, h: 0.65, fontSize: 12, fontFace: "Calibri", valign: "middle" });
  });

  // Bottom note
  addCard(s, 0.5, 7.0, 12.3, 0.35, "102040", GOLD);
  s.addText("Both methods use the same Beer-Lambert principle — they differ only in WHEN the measurement is taken.", {
    x: 0.65, y: 7.0, w: 12.0, h: 0.35, fontSize: 11, color: GOLD_LIGHT, italic: true, fontFace: "Calibri", valign: "middle"
  });
}

// ════════════════════════════════════════════════════════════
// SLIDE 8 – Clinical Applications
// ════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  addBg(s);
  addTopBar(s);
  addBottomBar(s);
  addSideStrip(s, 0, GOLD, 0.4);
  addCornerDots(s);
  addTitleStrip(s, "Clinical Applications", 0.25);
  addSlideNum(s, 8, TOTAL);

  const categories = [
    {
      title: "Carbohydrates",
      items: ["Glucose (fasting/PP/RBS)", "HbA1c (glycated Hb)"],
      color: GOLD, x: 0.5, y: 1.15
    },
    {
      title: "Renal Function",
      items: ["Urea (BUN)", "Creatinine", "Uric Acid"],
      color: TEAL, x: 4.7, y: 1.15
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      title: "Liver Function",
      items: ["Total Bilirubin", "Direct Bilirubin", "Serum Proteins"],
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      title: "Lipid Profile",
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// ════════════════════════════════════════════════════════════
// SLIDE 9 – Colorimeter vs Spectrophotometer
// ════════════════════════════════════════════════════════════
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    ["Cost",            "Low",                           "~100× more expensive"],
    ["Applications",    "Routine clinical tests",        "Research, specialized assays"]
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// ════════════════════════════════════════════════════════════
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// ════════════════════════════════════════════════════════════
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    { icon: "🔬",      text: "End-point analysis (37°C, 10 min) for metabolites; kinetic for enzymes", color: GREEN },
    { icon: "🏥",      text: "Measures glucose, urea, creatinine, bilirubin, lipids, enzymes and more", color: LIGHT_BLUE },
    { icon: "📊",      text: "Spectrophotometer is 1000× more sensitive but 100× more costly", color: RED_SOFT }
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// ─── Write File ───────────────────────────────────────────────────────────────
const outPath = path.resolve(__dirname, "Colorimeter.pptx");
pres.writeFile({ fileName: outPath })
  .then(() => console.log(`\n✅  Saved: ${outPath}`))
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 * Colorimeter Presentation — PptxGenJS
 * Source: 3 PDF files (OCR extracted)
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const path = require("path");

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// ─── Presentation ─────────────────────────────────────────────────────────────
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pres.layout  = "LAYOUT_WIDE";
pres.title   = "Colorimeter";
pres.author  = "Orris AI";
pres.subject = "Clinical Biochemistry";

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// ══════════════════════════════════════════════════
// SLIDE 1 — Title
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    { text:" or ", options:{ color:C.white } },
    { text:"transmittance", options:{ bold:true, color:C.teal } },
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    "or transmitted is governed by the Beer-Lambert Law. The color intensity is DIRECTLY " +
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    { year:"1825–1863", name:"August Beer",             contrib:"Beer's Law — Absorbance ∝ Concentration", col:C.green },
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// SLIDE 3 — Beer's Law
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// SLIDE 4 — Lambert's Law
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// ══════════════════════════════════════════════════
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    { sym:"ε",  full:"Molar Absorptivity",                      detail:"Units: L · mol⁻¹ · cm⁻¹  (property of substance)", col:C.teal    },
    { sym:"c",  full:"Concentration",                           detail:"Molar concentration of solution (mol/L)",           col:C.green   },
    { sym:"l",  full:"Path Length",                             detail:"Distance light travels through cuvette (cm)",       col:C.lightBlue },
  ];
  legend.forEach((item, i) => {
    const xx = 0.5 + (i % 2) * 6.4;
    const yy = 2.9 + Math.floor(i / 2) * 1.55;
    card(s, xx, yy, 6.1, 1.35, C.navyCard, item.col, 1.0);
    s.addShape("rect", { x:xx, y:yy, w:1.0, h:1.35, fill:{ color:item.col } });
    s.addText(item.sym, { x:xx, y:yy, w:1.0, h:1.35, fontSize:34, bold:true, color:C.navyDeep, align:"center", valign:"middle", fontFace:"Courier New", margin:0 });
    s.addText(item.full,   { x:xx+1.1, y:yy+0.12, w:4.85, h:0.48, fontSize:14, bold:true, color:C.white, fontFace:"Calibri" });
    s.addText(item.detail, { x:xx+1.1, y:yy+0.65, w:4.85, h:0.58, fontSize:12, color:C.grey,  fontFace:"Calibri", italic:true });
  });

  // Footer note
  card(s, 0.5, 6.9, 12.3, 0.45, "061525", C.gold, 0.8);
  s.addText(
    "Key insight: In colorimetry, path length (l) is held CONSTANT by using cuvettes of the same diameter — so only concentration (c) varies.",
    { x:0.65, y:6.9, w:12.0, h:0.45, fontSize:11.5, color:C.goldLight, italic:true, fontFace:"Calibri", valign:"middle" }
  );
}

// ══════════════════════════════════════════════════
// SLIDE 6 — Components of a Colorimeter
// ══════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  topBar(s, C.gold);
  botBar(s, C.teal);
  leftStripe(s, C.teal);
  dotDeco(s);
  titleStrip(s, "Components of a Colorimeter");
  slideNum(s, 6, TOTAL);

  // Flow diagram row (simplified schematic)
  const flowItems = [
    { label:"Light\nSource",     sub:"Tungsten Lamp\n400–760 nm (visible)", col:C.gold    },
    { label:"Adjustable\nSlit",  sub:"Narrows and\ncontrols beam width",    col:C.teal    },
    { label:"Condensing\nLens",  sub:"Produces parallel\nbeam of light",    col:C.green   },
    { label:"Color\nFilter",     sub:"Selects complementary\nwavelength",   col:C.orange  },
    { label:"Cuvette\n(Sample)", sub:"Fixed diameter\nglass tube",          col:C.lightBlue },
    { label:"Photocell\nDetector",sub:"Converts light\nto electrical signal",col:C.purple },
    { label:"Galvano-\nmeter",   sub:"Displays OD\nor %Transmittance",      col:C.red     },
  ];

  const boxW = 1.68, boxH = 1.55, startX = 0.38, y = 1.12;
  flowItems.forEach((item, i) => {
    const xx = startX + i * (boxW + 0.14);
    card(s, xx, y, boxW, boxH, C.navyCard, item.col, 0.9);
    s.addShape("rect", { x:xx, y, w:boxW, h:0.35, fill:{ color:item.col } });
    s.addText(String(i+1), { x:xx, y, w:0.35, h:0.35, fontSize:10, bold:true, color:C.navyDeep, align:"center", valign:"middle", margin:0 });
    s.addText(item.label, {
      x:xx+0.05, y:y+0.38, w:boxW-0.1, h:0.6,
      fontSize:11, bold:true, color:C.white, align:"center", fontFace:"Calibri"
    });
    s.addText(item.sub, {
      x:xx+0.05, y:y+1.0, w:boxW-0.1, h:0.55,
      fontSize:9, color:C.grey, align:"center", fontFace:"Calibri", italic:true
    });
    // Arrow (except after last)
    if (i < flowItems.length - 1) {
      s.addShape("rect", { x:xx+boxW, y:y+0.65, w:0.12, h:0.15, fill:{ color:C.gold } });
      s.addText("▶", { x:xx+boxW, y:y+0.58, w:0.14, h:0.3, fontSize:10, color:C.gold, align:"center", valign:"middle", margin:0 });
    }
  });

  // Detailed descriptions below
  const descs = [
    { n:"Light Source", t:"Tungsten lamp is the standard light source. Emits white light in the visible spectrum (400–760 nm range)." },
    { n:"Slit & Lens",  t:"Adjustable slit controls beam width. Condensing lens converts diverging light into a parallel (collimated) beam." },
    { n:"Filter",       t:"The filter transmits only the wavelength complementary to the solution color, providing monochromatic light." },
    { n:"Cuvette",      t:"Special glass tube with uniform inner diameter. The fixed diameter keeps path length (L) constant for all measurements." },
    { n:"Photocell",    t:"Photoelectric detector converts transmitted light intensity into proportional electrical impulse (current)." },
    { n:"Display",      t:"Galvanometer/digital meter shows the reading as Absorbance (OD) or percent Transmittance (%T)." },
  ];

  descs.forEach((d, i) => {
    const xx = 0.5 + (i % 3) * 4.3;
    const yy = 2.95 + Math.floor(i / 3) * 1.68;
    card(s, xx, yy, 4.0, 1.48, "0E2440", C.teal, 0.7);
    s.addText(d.n, { x:xx+0.12, y:yy+0.08, w:3.76, h:0.35, fontSize:12.5, bold:true, color:C.teal, fontFace:"Calibri", margin:0 });
    s.addText(d.t, { x:xx+0.12, y:yy+0.45, w:3.76, h:0.95, fontSize:11.5, color:C.white, fontFace:"Calibri" });
  });
}

// ══════════════════════════════════════════════════
// SLIDE 7 — Operation (How it Works)
// ══════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  topBar(s, C.gold);
  botBar(s, C.teal);
  leftStripe(s, C.gold);
  dotDeco(s);
  titleStrip(s, "How a Colorimeter Works");
  slideNum(s, 7, TOTAL);

  const steps = [
    { n:"01", txt:"Tungsten lamp emits white light across the visible spectrum (400–760 nm).",                                   col:C.gold    },
    { n:"02", txt:"Light passes through an adjustable slit — beam width is controlled.",                                         col:C.teal    },
    { n:"03", txt:"Condensing lens converts diverging rays into a parallel (collimated) beam.",                                  col:C.green   },
    { n:"04", txt:"Color filter selects the wavelength complementary to the solution color — monochromatic light is produced.",  col:C.orange  },
    { n:"05", txt:"Monochromatic light enters the cuvette (fixed-diameter tube) containing the colored solution.",              col:C.lightBlue },
    { n:"06", txt:"The solution absorbs part of the light proportional to its concentration (Beer-Lambert Law).",               col:C.purple  },
    { n:"07", txt:"Remaining transmitted light hits the photocell, generating an electrical impulse.",                          col:C.red     },
    { n:"08", txt:"Galvanometer / digital meter displays the reading as Absorbance (OD) or %Transmittance.",                    col:C.goldLight },
  ];

  steps.forEach((st, i) => {
    const xx = 0.5 + (i % 2) * 6.4;
    const yy = 1.1 + Math.floor(i / 2) * 1.5;
    card(s, xx, yy, 6.1, 1.3, C.navyCard, st.col, 0.8);
    s.addShape("ellipse", { x:xx+0.08, y:yy+0.42, w:0.48, h:0.48, fill:{ color:st.col } });
    s.addText(st.n, { x:xx+0.08, y:yy+0.42, w:0.48, h:0.48, fontSize:10, bold:true, color:C.navyDeep, align:"center", valign:"middle", fontFace:"Courier New", margin:0 });
    s.addText(st.txt, { x:xx+0.65, y:yy, w:5.3, h:1.3, fontSize:12, color:C.white, fontFace:"Calibri", valign:"middle" });
  });
}

// ══════════════════════════════════════════════════
// SLIDE 8 — Types of Analysis
// ══════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  topBar(s, C.gold);
  botBar(s, C.teal);
  leftStripe(s, C.teal);
  dotDeco(s);
  titleStrip(s, "Types of Colorimetric Analysis");
  slideNum(s, 8, TOTAL);

  // ---- End-point Analysis card ----
  card(s, 0.5, 1.1, 5.9, 5.9, C.navyCard, C.teal, 1.2);
  s.addShape("rect", { x:0.5, y:1.1, w:5.9, h:0.55, fill:{ color:C.teal } });
  s.addText("1. End-Point Analysis", { x:0.6, y:1.1, w:5.7, h:0.55, fontSize:15, bold:true, color:C.navyDeep, valign:"middle", margin:0 });

  const epPoints = [
    "Serum + reagents are mixed and incubated",
    "Incubated at 37°C for a FIXED TIME (10 min)",
    "Color is allowed to develop to COMPLETION",
    "Single OD reading is taken after incubation",
    "Concentration is calculated using:\n  C(unknown) = [(OD Test − OD Blank) / (OD Std − OD Blank)] × C(std)",
    "Used for: Glucose, Urea, Creatinine, Uric Acid,\n  Bilirubin, Lipids, Total Proteins"
  ];
  epPoints.forEach((pt, i) => {
    s.addText([
      { text:"▸ ", options:{ bold:true, color:C.teal } },
      { text:pt, options:{ color:C.white } }
    ], { x:0.7, y:1.78 + i*0.73, w:5.55, h:0.65, fontSize:11.5, fontFace:"Calibri", valign:"middle" });
  });

  // ---- Kinetic Analysis card ----
  card(s, 6.9, 1.1, 5.9, 5.9, C.navyCard, C.green, 1.2);
  s.addShape("rect", { x:6.9, y:1.1, w:5.9, h:0.55, fill:{ color:C.green } });
  s.addText("2. Kinetic Analysis", { x:7.0, y:1.1, w:5.7, h:0.55, fontSize:15, bold:true, color:C.navyDeep, valign:"middle", margin:0 });

  const kinPoints = [
    "Measures RATE of change in absorbance over time",
    "Optimum color is NOT waited for",
    "Readings taken at EXACTLY 2 and 3 minutes",
    "ΔOD per minute is used for calculation",
    "Faster than end-point — used in autoanalyzers",
    "Used for ENZYMES:\n  AST (SGOT), ALT (SGPT), ALP, LDH"
  ];
  kinPoints.forEach((pt, i) => {
    s.addText([
      { text:"▸ ", options:{ bold:true, color:C.green } },
      { text:pt, options:{ color:C.white } }
    ], { x:7.1, y:1.78 + i*0.73, w:5.55, h:0.65, fontSize:11.5, fontFace:"Calibri", valign:"middle" });
  });

  // Bottom comparison note
  card(s, 0.5, 7.1, 12.3, 0.28, "061525", C.gold, 0.7);
  s.addText("Both methods obey Beer-Lambert Law — the ONLY difference is WHEN the OD reading is taken.", {
    x:0.65, y:7.1, w:12.0, h:0.28, fontSize:11, color:C.goldLight, italic:true, fontFace:"Calibri", valign:"middle"
  });
}

// ══════════════════════════════════════════════════
// SLIDE 9 — Calculations
// ══════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  topBar(s, C.gold);
  botBar(s, C.teal);
  leftStripe(s, C.gold);
  dotDeco(s);
  titleStrip(s, "Calculations in Colorimetry");
  slideNum(s, 9, TOTAL);

  // Main formula block
  card(s, 0.8, 1.1, 11.7, 1.6, "061525", C.gold, 1.5);
  s.addText("C(unknown)  =  [ (OD Test − OD Blank) / (OD Standard − OD Blank) ]  ×  C(Standard)", {
    x:0.9, y:1.1, w:11.5, h:1.6,
    fontSize:20, bold:true, color:C.gold,
    align:"center", valign:"middle", fontFace:"Courier New", margin:0
  });

  // Term definitions
  const terms = [
    { term:"OD Test",      def:"Optical density (absorbance) of the TEST sample",      col:C.gold    },
    { term:"OD Blank",     def:"OD of the Reagent Blank (subtracts reagent color)",     col:C.teal    },
    { term:"OD Standard",  def:"OD of a solution with KNOWN concentration",             col:C.green   },
    { term:"C(Standard)",  def:"Known concentration of the standard solution",          col:C.orange  },
    { term:"C(Unknown)",   def:"Calculated concentration of the test sample",           col:C.lightBlue },
    { term:"Reagent Blank","def":"Reagent without sample — zeros out background color", col:C.purple  },
  ];
  terms.forEach((t, i) => {
    const xx = 0.5 + (i % 2) * 6.4;
    const yy = 3.0 + Math.floor(i / 2) * 0.92;
    card(s, xx, yy, 6.1, 0.78, C.navyCard, t.col, 0.8);
    s.addShape("rect", { x:xx, y:yy, w:1.9, h:0.78, fill:{ color:t.col } });
    s.addText(t.term, { x:xx+0.05, y:yy, w:1.8, h:0.78, fontSize:11, bold:true, color:C.navyDeep, align:"center", valign:"middle", margin:0 });
    s.addText(t.def, { x:xx+2.05, y:yy, w:3.9, h:0.78, fontSize:12, color:C.white, fontFace:"Calibri", valign:"middle" });
  });

  // Extended formula from source 2
  card(s, 0.5, 5.85, 12.3, 1.45, "0E2440", C.orange, 0.9);
  s.addText("Extended formula (from Essentials of Biochemistry):", { x:0.65, y:5.88, w:12.0, h:0.35, fontSize:12, bold:true, color:C.orange, fontFace:"Calibri", margin:0 });
  s.addText("% Concentration of test  =  [ (OD Test − OD Blank) / (OD Standard − OD Blank) ]  ×  (Conc. of Std / Volume of test)  ×  100", {
    x:0.65, y:6.25, w:12.0, h:0.95, fontSize:13, color:C.white, fontFace:"Courier New", valign:"middle"
  });
}

// ══════════════════════════════════════════════════
// SLIDE 10 — Clinical Applications
// ══════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  topBar(s, C.gold);
  botBar(s, C.teal);
  leftStripe(s, C.teal);
  dotDeco(s);
  titleStrip(s, "Clinical Applications of Colorimeter");
  slideNum(s, 10, TOTAL);

  // Intro sentence
  s.addText(
    "Colorimetric procedures are widely used in clinical laboratories to estimate biochemical compounds in blood, plasma, serum, CSF, urine and other body fluids.",
    { x:0.5, y:1.1, w:12.3, h:0.7, fontSize:13, color:C.grey, fontFace:"Calibri" }
  );

  const cats = [
    { title:"Carbohydrates",     items:["Glucose (Fasting/PP/RBS)", "HbA1c (Glycated Haemoglobin)"],                          col:C.gold,     x:0.5,  y:2.0  },
    { title:"Renal Function",    items:["Urea (Blood Urea Nitrogen)", "Creatinine", "Uric Acid"],                              col:C.teal,     x:4.55, y:2.0  },
    { title:"Liver Function",    items:["Total Bilirubin", "Direct Bilirubin", "Serum Proteins"],                              col:C.green,    x:8.65, y:2.0  },
    { title:"Lipid Profile",     items:["Total Cholesterol", "Triglycerides", "HDL / LDL (calc)"],                            col:C.orange,   x:0.5,  y:4.35 },
    { title:"Enzymes (Kinetic)", items:["AST / SGOT", "ALT / SGPT", "ALP, LDH (liver enzymes)"],                             col:C.red,      x:4.55, y:4.35 },
    { title:"Minerals & Others", items:["Calcium (Ca)", "Phosphorus (P)", "Total Protein, Albumin"],                          col:C.purple,   x:8.65, y:4.35 },
  ];

  cats.forEach(cat => {
    const cH = 2.15;
    card(s, cat.x, cat.y, 3.85, cH, C.navyCard, cat.col, 1.0);
    s.addShape("rect", { x:cat.x, y:cat.y, w:3.85, h:0.45, fill:{ color:cat.col } });
    s.addText(cat.title, { x:cat.x+0.08, y:cat.y, w:3.69, h:0.45, fontSize:13, bold:true, color:C.navyDeep, align:"center", valign:"middle", margin:0 });
    cat.items.forEach((item, idx) => {
      s.addText([
        { text:"● ", options:{ color:cat.col, bold:true } },
        { text:item, options:{ color:C.white } }
      ], { x:cat.x+0.15, y:cat.y+0.52 + idx*0.52, w:3.55, h:0.48, fontSize:12, fontFace:"Calibri", valign:"middle" });
    });
  });

  // Bottom info strip
  card(s, 0.5, 6.62, 12.3, 0.72, "0E2440", C.gold, 0.8);
  s.addText("Biological samples used: Blood · Plasma · Serum · Cerebrospinal fluid (CSF) · Urine · Other body fluids", {
    x:0.65, y:6.65, w:12.0, h:0.65, fontSize:13, color:C.goldLight, fontFace:"Calibri", valign:"middle"
  });
}

// ══════════════════════════════════════════════════
// SLIDE 11 — Colorimeter vs Spectrophotometer
// ══════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  topBar(s, C.gold);
  botBar(s, C.teal);
  leftStripe(s, C.gold);
  dotDeco(s);
  titleStrip(s, "Colorimeter  vs  Spectrophotometer");
  slideNum(s, 11, TOTAL);

  // Table headers
  const colX = [0.5, 4.2, 8.8];
  const colW = [3.5, 4.35, 4.35];
  const hdrs = ["Feature", "Colorimeter", "Spectrophotometer"];
  const hdrCols = [C.navyMid, C.teal, C.gold];

  hdrs.forEach((h, i) => {
    card(s, colX[i], 1.1, colW[i], 0.58, hdrCols[i], hdrCols[i]);
    s.addText(h, { x:colX[i]+0.08, y:1.1, w:colW[i]-0.16, h:0.58, fontSize:14, bold:true, color: i===0 ? C.goldLight : C.navyDeep, align:"center", valign:"middle", margin:0 });
  });

  const rows = [
    ["Light Source",      "Tungsten lamp",                    "Tungsten + Deuterium / Xenon"],
    ["Wavelength Sel.",   "Glass/gelatin color filters",      "Diffraction gratings (prism)"],
    ["Range",             "Visible only: 400–760 nm",         "UV + Visible + IR: ~200–900 nm"],
    ["Cuvettes",          "Glass or plastic cuvettes",        "Quartz cuvettes (UV transparent)"],
    ["Sensitivity",       "Standard sensitivity",             "~1000× MORE sensitive"],
    ["Cost",              "Low cost — routine labs",          "~100× more expensive"],
    ["Applications",      "Routine clinical biochemistry",    "Research & specialized assays"],
  ];

  rows.forEach((row, ri) => {
    const yy = 1.72 + ri * 0.74;
    const rowBg = ri % 2 === 0 ? C.navyCard : C.navyMid;
    row.forEach((cell, ci) => {
      card(s, colX[ci], yy, colW[ci], 0.7, rowBg, rowBg);
      const textCol = ci===0 ? C.goldLight : ci===1 ? C.teal : C.white;
      s.addText(cell, { x:colX[ci]+0.12, y:yy, w:colW[ci]-0.24, h:0.7, fontSize:12, color:textCol, fontFace:"Calibri", valign:"middle" });
    });
  });

  // Key differentiator box
  card(s, 0.5, 7.04, 12.3, 0.36, "061525", C.orange, 0.9);
  s.addText(
    "Key difference: Spectrophotometer is 1000× more sensitive but 100× more expensive — uses diffraction gratings & quartz cuvettes for UV range.",
    { x:0.65, y:7.04, w:12.0, h:0.36, fontSize:11, color:C.goldLight, italic:true, fontFace:"Calibri", valign:"middle" }
  );
}

// ─── Write file ───────────────────────────────────────────────────────────────
const outFile = path.resolve(__dirname, "Colorimeter.pptx");
pres.writeFile({ fileName: outFile })
  .then(() => console.log("\n✅  Created: " + outFile))
  .catch(err => { console.error("ERROR:", err); process.exit(1); });