const {
  Document, Packer, Paragraph, TextRun, Table, TableRow, TableCell,
  HeadingLevel, AlignmentType, LevelFormat, BorderStyle, WidthType,
  ShadingType, VerticalAlign, PageNumber, UnderlineType
} = require('docx');
const fs = require('fs');

// ─── Colour palette ───────────────────────────────────────────────────────────
const TEAL   = "0077A8";   // header / section title backgrounds
const LTBLUE = "E8F4FA";   // light info box background
const WHITE  = "FFFFFF";
const DARK   = "1A1A1A";
const ORANGE = "E05C00";   // warning highlight

// ─── Helper: bold coloured run ────────────────────────────────────────────────
const boldRun = (text, color = DARK, size = 24) =>
  new TextRun({ text, bold: true, color, size, font: "Arial" });

const normalRun = (text, color = DARK, size = 22) =>
  new TextRun({ text, color, size, font: "Arial" });

const italicRun = (text, color = "555555", size = 20) =>
  new TextRun({ text, italics: true, color, size, font: "Arial" });

// ─── Helper: section heading paragraph ───────────────────────────────────────
const sectionHeading = (text) =>
  new Paragraph({
    spacing: { before: 200, after: 100 },
    shading: { type: ShadingType.SOLID, color: TEAL, fill: TEAL },
    indent: { left: 200, right: 200 },
    children: [
      new TextRun({ text: "  " + text + "  ", bold: true, color: WHITE, size: 26, font: "Arial" })
    ]
  });

// ─── Helper: bullet paragraph ────────────────────────────────────────────────
const bullet = (text, bold_part = "", rest = "") =>
  new Paragraph({
    numbering: { reference: "bullets", level: 0 },
    spacing: { before: 60, after: 60 },
    children: bold_part
      ? [boldRun(bold_part), normalRun(rest)]
      : [normalRun(text)]
  });

// ─── Helper: plain paragraph ─────────────────────────────────────────────────
const para = (text, align = AlignmentType.LEFT, spacing_after = 120) =>
  new Paragraph({
    alignment: align,
    spacing: { before: 60, after: spacing_after },
    children: [normalRun(text)]
  });

// ─── Helper: info box (shaded table) ─────────────────────────────────────────
const infoBox = (heading, lines) =>
  new Table({
    width: { size: 100, type: WidthType.PERCENTAGE },
    margins: { top: 80, bottom: 80, left: 160, right: 160 },
    borders: {
      top:    { style: BorderStyle.SINGLE, size: 8, color: TEAL },
      bottom: { style: BorderStyle.SINGLE, size: 8, color: TEAL },
      left:   { style: BorderStyle.SINGLE, size: 8, color: TEAL },
      right:  { style: BorderStyle.SINGLE, size: 8, color: TEAL },
    },
    rows: [
      new TableRow({ children: [
        new TableCell({
          shading: { type: ShadingType.SOLID, color: LTBLUE, fill: LTBLUE },
          verticalAlign: VerticalAlign.CENTER,
          children: [
            new Paragraph({ spacing: { before: 60, after: 80 }, children: [
              boldRun(heading, TEAL, 24)
            ]}),
            ...lines.map(l =>
              new Paragraph({ spacing: { before: 40, after: 40 }, children: [normalRun(l)] })
            )
          ]
        })
      ]})
    ]
  });

// ─── Helper: warning box ─────────────────────────────────────────────────────
const warningBox = (heading, lines) =>
  new Table({
    width: { size: 100, type: WidthType.PERCENTAGE },
    borders: {
      top:    { style: BorderStyle.SINGLE, size: 8, color: ORANGE },
      bottom: { style: BorderStyle.SINGLE, size: 8, color: ORANGE },
      left:   { style: BorderStyle.THICK,  size: 16, color: ORANGE },
      right:  { style: BorderStyle.SINGLE, size: 8, color: ORANGE },
    },
    rows: [
      new TableRow({ children: [
        new TableCell({
          shading: { type: ShadingType.SOLID, color: "FFF3EC", fill: "FFF3EC" },
          children: [
            new Paragraph({ spacing: { before: 60, after: 80 }, children: [
              new TextRun({ text: "⚠  " + heading, bold: true, color: ORANGE, size: 24, font: "Arial" })
            ]}),
            ...lines.map(l =>
              new Paragraph({ spacing: { before: 40, after: 40 }, children: [normalRun(l)] })
            )
          ]
        })
      ]})
    ]
  });

// ─── Spacer ───────────────────────────────────────────────────────────────────
const spacer = (pts = 80) =>
  new Paragraph({ spacing: { before: pts, after: 0 }, children: [new TextRun("")] });

// ─── Document ─────────────────────────────────────────────────────────────────
const doc = new Document({
  numbering: {
    config: [
      {
        reference: "bullets",
        levels: [{
          level: 0, format: LevelFormat.BULLET, text: "\u2022",
          alignment: AlignmentType.LEFT,
          style: { paragraph: { indent: { left: 480, hanging: 240 } } }
        }]
      }
    ]
  },
  styles: {
    default: {
      document: { run: { font: "Arial", size: 22, color: DARK } }
    }
  },
  sections: [{
    properties: {
      page: {
        margin: { top: 720, bottom: 720, left: 900, right: 900 }
      }
    },
    children: [

      // ── TITLE BANNER ──────────────────────────────────────────────────────
      new Table({
        width: { size: 100, type: WidthType.PERCENTAGE },
        borders: {
          top:    { style: BorderStyle.NONE },
          bottom: { style: BorderStyle.NONE },
          left:   { style: BorderStyle.NONE },
          right:  { style: BorderStyle.NONE },
          insideH:{ style: BorderStyle.NONE },
          insideV:{ style: BorderStyle.NONE },
        },
        rows: [
          new TableRow({ children: [
            new TableCell({
              shading: { type: ShadingType.SOLID, color: TEAL, fill: TEAL },
              verticalAlign: VerticalAlign.CENTER,
              children: [
                new Paragraph({
                  alignment: AlignmentType.CENTER,
                  spacing: { before: 160, after: 60 },
                  children: [
                    new TextRun({ text: "PATIENT INFORMATION LEAFLET", bold: true, color: WHITE, size: 40, font: "Arial" })
                  ]
                }),
                new Paragraph({
                  alignment: AlignmentType.CENTER,
                  spacing: { before: 0, after: 160 },
                  children: [
                    new TextRun({ text: "[Condition / Medication / Procedure Name]", color: "CCEEFF", size: 26, font: "Arial", italics: true })
                  ]
                })
              ]
            })
          ]})
        ]
      }),

      spacer(120),

      // ── INTRO ─────────────────────────────────────────────────────────────
      para(
        "This leaflet has been written to help you understand your condition and what to expect. " +
        "Please read it carefully and keep it for future reference. If you have any questions, " +
        "do not hesitate to speak to your doctor, nurse, or pharmacist.",
        AlignmentType.LEFT, 160
      ),

      // ── SECTION 1: WHAT IS IT? ────────────────────────────────────────────
      sectionHeading("1.  What is [Condition / Medication / Procedure]?"),
      spacer(60),
      para(
        "[Provide a clear, jargon-free explanation of what this condition, medication, or procedure " +
        "is. Use simple language — aim for a reading age of around 12 years old.]"
      ),
      para(
        "Key facts:"
      ),
      bullet("", "How common it is: ", "[e.g. It affects approximately 1 in 100 people in the UK.]"),
      bullet("", "Who is affected: ", "[e.g. It can occur at any age, but is most common in adults over 40.]"),
      bullet("", "Is it serious? ", "[e.g. It is usually a manageable condition with the right treatment.]"),
      spacer(80),

      // ── SECTION 2: CAUSES ─────────────────────────────────────────────────
      sectionHeading("2.  Causes and Risk Factors"),
      spacer(60),
      para("[Describe the known causes or contributing factors. List risk factors where relevant.]"),
      bullet("Risk factor 1"),
      bullet("Risk factor 2"),
      bullet("Risk factor 3"),
      spacer(80),

      // ── SECTION 3: SYMPTOMS ───────────────────────────────────────────────
      sectionHeading("3.  Symptoms"),
      spacer(60),
      para(
        "Common symptoms include:"
      ),
      bullet("Symptom 1"),
      bullet("Symptom 2"),
      bullet("Symptom 3"),
      spacer(80),

      warningBox(
        "When to seek urgent medical help",
        [
          "Call 999 or go to your nearest A&E immediately if you experience:",
          "  \u2022  [Urgent symptom 1 — e.g. sudden severe chest pain]",
          "  \u2022  [Urgent symptom 2 — e.g. difficulty breathing]",
          "  \u2022  [Urgent symptom 3 — e.g. signs of severe allergic reaction]",
        ]
      ),
      spacer(120),

      // ── SECTION 4: DIAGNOSIS ──────────────────────────────────────────────
      sectionHeading("4.  Diagnosis"),
      spacer(60),
      para("[Explain how the condition is diagnosed — tests, examinations, imaging, etc.]"),
      bullet("Test / examination 1"),
      bullet("Test / examination 2"),
      bullet("Test / examination 3"),
      spacer(80),

      // ── SECTION 5: TREATMENT ──────────────────────────────────────────────
      sectionHeading("5.  Treatment Options"),
      spacer(60),
      para("[Summarise the main treatment options available.]"),
      spacer(40),
      infoBox(
        "Treatment Option 1 — [e.g. Medication]",
        [
          "How it works: [Brief explanation]",
          "How to take it: [Dosage, frequency]",
          "How long: [Duration of treatment]",
        ]
      ),
      spacer(80),
      infoBox(
        "Treatment Option 2 — [e.g. Lifestyle changes]",
        [
          "What to do: [Specific advice]",
          "Why it helps: [Brief explanation]",
        ]
      ),
      spacer(80),

      // ── SECTION 6: SIDE EFFECTS ───────────────────────────────────────────
      sectionHeading("6.  Side Effects and Risks"),
      spacer(60),
      para("Common side effects (affecting more than 1 in 10 people):"),
      bullet("Side effect 1"),
      bullet("Side effect 2"),
      spacer(40),
      para("Less common side effects (affecting 1 in 10 to 1 in 100 people):"),
      bullet("Side effect 3"),
      bullet("Side effect 4"),
      spacer(80),

      // ── SECTION 7: SELF-CARE ──────────────────────────────────────────────
      sectionHeading("7.  Self-Care and Lifestyle Advice"),
      spacer(60),
      bullet("Stay hydrated and maintain a balanced diet."),
      bullet("Exercise regularly as advised by your healthcare team."),
      bullet("Avoid smoking and limit alcohol intake."),
      bullet("[Add condition-specific self-care advice here.]"),
      spacer(80),

      // ── SECTION 8: FOLLOW-UP ──────────────────────────────────────────────
      sectionHeading("8.  Follow-Up Appointments"),
      spacer(60),
      para(
        "[Explain the follow-up schedule — when the patient should return, what will be checked, " +
        "and who to contact if they have concerns before their next appointment.]"
      ),
      spacer(80),

      // ── SECTION 9: FURTHER INFORMATION ───────────────────────────────────
      sectionHeading("9.  Further Information and Support"),
      spacer(60),
      bullet("", "Your GP: ", "Contact your GP surgery for advice and referrals."),
      bullet("", "NHS Helpline: ", "Call 111 for non-emergency medical advice (UK)."),
      bullet("", "Support groups: ", "[Name of relevant patient charity / organisation, website URL]"),
      bullet("", "NHS website: ", "www.nhs.uk — search for your condition."),
      spacer(80),

      // ── FOOTER INFO ───────────────────────────────────────────────────────
      new Table({
        width: { size: 100, type: WidthType.PERCENTAGE },
        borders: {
          top:    { style: BorderStyle.SINGLE, size: 4, color: "AAAAAA" },
          bottom: { style: BorderStyle.NONE },
          left:   { style: BorderStyle.NONE },
          right:  { style: BorderStyle.NONE },
          insideH:{ style: BorderStyle.NONE },
          insideV:{ style: BorderStyle.NONE },
        },
        rows: [
          new TableRow({ children: [
            new TableCell({
              children: [
                new Paragraph({
                  spacing: { before: 80, after: 40 },
                  children: [italicRun("Produced by: [Department / Organisation Name]")]
                }),
                new Paragraph({
                  spacing: { before: 0, after: 40 },
                  children: [italicRun("Date produced: [Month Year]   |   Review date: [Month Year]   |   Ref: [Reference number]")]
                }),
                new Paragraph({
                  spacing: { before: 0, after: 40 },
                  children: [italicRun(
                    "This leaflet is for informational purposes only and does not replace professional medical advice. " +
                    "Always consult a qualified healthcare professional for diagnosis and treatment."
                  )]
                }),
              ]
            })
          ]})
        ]
      }),
    ]
  }]
});

Packer.toBuffer(doc).then(buffer => {
  fs.writeFileSync("/home/daytona/workspace/patient-leaflet/Patient_Information_Leaflet_Template.docx", buffer);
  console.log("Done — file written.");
});