const docx = require("docx");
const {
  Document, Paragraph, TextRun, Table, TableRow, TableCell,
  WidthType, AlignmentType, BorderStyle, ShadingType,
  Header, Footer, PageNumber, HeadingLevel, TableLayoutType,
  convertInchesToTwip
} = docx;

// ── Color constants ──
const COLORS = {
  PRIMARY: "1F3864",
  ACCENT: "2E75B6",
  TABLE_HEADER_FILL: "D6E4F0",
  TABLE_ALT_ROW: "F2F2F2",
  TABLE_BORDER: "CCCCCC",
  HEADER_TEXT: "FFFFFF",
  FOOTER_TEXT: "666666",
};

const FONT = "Arial";

// ── 1. createHeaderBanner ──
// Returns an array of docx elements: [banner paragraph, key-value table]
function createHeaderBanner(companyName, leftFields, rightFields) {
  // leftFields / rightFields: arrays of { label: string, value: string }
  const banner = new Paragraph({
    children: [
      new TextRun({
        text: companyName,
        bold: true,
        size: 36, // 18pt
        color: COLORS.HEADER_TEXT,
        font: FONT,
      }),
    ],
    shading: { type: ShadingType.CLEAR, color: "auto", fill: COLORS.PRIMARY },
    spacing: { after: 0 },
    alignment: AlignmentType.LEFT,
  });

  function buildCellParagraphs(fields) {
    return fields.map(
      (f) =>
        new Paragraph({
          children: [
            new TextRun({ text: f.label + "  ", bold: true, size: 18, font: FONT }),
            new TextRun({ text: f.value, size: 18, font: FONT }),
          ],
          spacing: { after: 40 },
        })
    );
  }

  const noBorder = { style: BorderStyle.NONE, size: 0, color: "FFFFFF" };
  const noBorders = { top: noBorder, bottom: noBorder, left: noBorder, right: noBorder };
  const noShading = { type: ShadingType.CLEAR, color: "auto", fill: "FFFFFF" };

  const kvTable = new Table({
    rows: [
      new TableRow({
        children: [
          new TableCell({
            children: buildCellParagraphs(leftFields),
            width: { size: 50, type: WidthType.PERCENTAGE },
            borders: noBorders,
            shading: noShading,
          }),
          new TableCell({
            children: buildCellParagraphs(rightFields),
            width: { size: 50, type: WidthType.PERCENTAGE },
            borders: noBorders,
            shading: noShading,
          }),
        ],
      }),
    ],
    width: { size: 100, type: WidthType.PERCENTAGE },
  });

  return [banner, kvTable];
}

// ── 2. createSectionHeader ──
// Returns a single Paragraph with bottom border rule
function createSectionHeader(text) {
  return new Paragraph({
    children: [
      new TextRun({
        text: text,
        bold: true,
        size: 22, // 11pt
        color: COLORS.PRIMARY,
        font: FONT,
      }),
    ],
    spacing: { before: 240, after: 0 }, // 12pt before, 0pt after
    border: {
      bottom: { style: BorderStyle.SINGLE, size: 1, color: COLORS.TABLE_BORDER },
    },
  });
}

// ── 3. createTable ──
// headers: string[], rows: string[][], options: { accentHeader?, fontSize? }
function createTable(headers, rows, options = {}) {
  const fontSize = options.fontSize || 17; // 8.5pt default
  const headerFill = options.accentHeader ? COLORS.ACCENT : COLORS.TABLE_HEADER_FILL;
  const headerTextColor = options.accentHeader ? COLORS.HEADER_TEXT : "000000";

  const cellBorders = {
    top: { style: BorderStyle.SINGLE, size: 1, color: COLORS.TABLE_BORDER },
    bottom: { style: BorderStyle.SINGLE, size: 1, color: COLORS.TABLE_BORDER },
    left: { style: BorderStyle.SINGLE, size: 1, color: COLORS.TABLE_BORDER },
    right: { style: BorderStyle.SINGLE, size: 1, color: COLORS.TABLE_BORDER },
  };

  const cellMargins = { top: 40, bottom: 40, left: 80, right: 80 };

  function isNumeric(val) {
    if (typeof val !== "string") return false;
    const cleaned = val.replace(/[,$%()]/g, "").trim();
    return cleaned !== "" && !isNaN(cleaned);
  }

  // Header row
  const headerRow = new TableRow({
    children: headers.map(
      (h) =>
        new TableCell({
          children: [
            new Paragraph({
              children: [
                new TextRun({
                  text: h,
                  bold: true,
                  size: fontSize,
                  color: headerTextColor,
                  font: FONT,
                }),
              ],
            }),
          ],
          shading: { type: ShadingType.CLEAR, color: "auto", fill: headerFill },
          borders: cellBorders,
          margins: cellMargins,
        })
    ),
  });

  // Data rows with alternating shading
  const dataRows = rows.map((row, rowIdx) => {
    const fill = rowIdx % 2 === 1 ? COLORS.TABLE_ALT_ROW : "FFFFFF";
    return new TableRow({
      children: row.map((cell, colIdx) => {
        const align = colIdx > 0 && isNumeric(cell)
          ? AlignmentType.RIGHT
          : AlignmentType.LEFT;
        return new TableCell({
          children: [
            new Paragraph({
              children: [
                new TextRun({ text: cell, size: fontSize, font: FONT }),
              ],
              alignment: align,
            }),
          ],
          shading: { type: ShadingType.CLEAR, color: "auto", fill: fill },
          borders: cellBorders,
          margins: cellMargins,
        });
      }),
    });
  });

  return new Table({
    rows: [headerRow, ...dataRows],
    width: { size: 100, type: WidthType.PERCENTAGE },
  });
}

// ── 4. createBulletList ──
// items: string[], style: "synthesis" | "informational"
function createBulletList(items, style = "synthesis") {
  const indent =
    style === "synthesis"
      ? { left: 360, hanging: 180 }   // 360 DXA left, hanging indent for bullet
      : { left: 180 };                 // 180 DXA, no hanging

  return items.map(
    (item) =>
      new Paragraph({
        children: [
          new TextRun({ text: "•  ", font: FONT, size: 18 }),
          new TextRun({ text: item, font: FONT, size: 18 }),
        ],
        indent: indent,
        spacing: { after: 60 },
      })
  );
}

// ── 5. createFooter ──
// date: string (e.g., "February 23, 2026")
function createFooter(date) {
  return new Footer({
    children: [
      new Paragraph({
        children: [
          new TextRun({
            text: `Data: S&P Capital IQ via Kensho | Analysis: AI-generated | ${date}`,
            italics: true,
            size: 14, // 7pt
            color: COLORS.FOOTER_TEXT,
            font: FONT,
          }),
        ],
        alignment: AlignmentType.CENTER,
      }),
      new Paragraph({
        children: [
          new TextRun({
            text: "For informational purposes only. Not investment advice.",
            italics: true,
            size: 14,
            color: COLORS.FOOTER_TEXT,
            font: FONT,
          }),
        ],
        alignment: AlignmentType.CENTER,
      }),
    ],
  });
}

mkdir -p /tmp/tear-sheet/

metric,value,formula,components
gross_margin_fy2024,72.4%,gross_profit/revenue,"9524/13159"
revenue_growth_fy2024,12.3%,(current-prior)/prior,"13159/11716"
net_debt_fy2024,2150,total_debt-cash,"4200-2050"

=== Tear Sheet Data Verification ===
company-profile.txt: ✓ (12 fields)
financials.csv:      ✓ (36 rows)
segments.csv:        ✓ (8 rows)
valuation.csv:       ✓ (5 rows)
calculations.csv:    ✓ (18 rows)
earnings.txt:        ✓ (populated)
relationships.txt:   ⚠ MISSING
peer-comps.csv:      ✓ (12 rows)
================================

mkdir -p /tmp/tear-sheet/