Function buildPdf

src/cli/pdf-lite.ts:74–147

(blocks: PdfBlock[])

 * with `Buffer.from(pdf, 'latin1')`. PURE + deterministic (no clock, no randomness).
 */
export function buildPdf(blocks: PdfBlock[]): string {
  // 1. Lay blocks out into pages of positioned elements (text lines + bar-chart rows).
  interface Line { kind: 'text'; x: number; y: number; size: number; font: 'F1' | 'F2' | 'F3'; text: string }
  interface BarsRow { kind: 'bars'; x: number; y: number; values: number[]; label: string; size: number }
  type El = Line | BarsRow;
  const BAR_H = 36; const BAR_W = 14; const BAR_GAP = 4;
  const pages: El[][] = [[]];
  let y = PAGE_H - MARGIN;
  for (const b of blocks) {
    const size = b.size ?? 11;
    const x = MARGIN + (b.indent ?? 0);
    y -= b.spaceBefore ?? 0;
    if (b.bars) {
      if (y < MARGIN + BAR_H + size) { pages.push([]); y = PAGE_H - MARGIN; }
      y -= BAR_H + Math.round(size * 0.6);
      pages[pages.length - 1]!.push({ kind: 'bars', x, y, values: b.bars, label: pdfSanitize(b.text), size });
      continue;
    }
    const gap = Math.round(size * 1.45);
    const font = b.mono ? 'F3' : b.bold ? 'F2' : 'F1';
    for (const lineText of wrap(pdfSanitize(b.text), size, !!b.mono, PAGE_W - x - MARGIN)) {
      if (y < MARGIN + size) { pages.push([]); y = PAGE_H - MARGIN; }
      y -= gap;
      pages[pages.length - 1]!.push({ kind: 'text', x, y, size, font, text: lineText });
    }
  }

  // 2. Emit objects, tracking byte offsets for the xref table.
  //    Layout: 1 Catalog · 2 Pages · 3 F1 · 4 F2 · 5 F3 · then per page: Page, Contents.
  const objects: string[] = [];
  const firstPageObj = 6;
  const kids = pages.map((_, i) => `${firstPageObj + i * 2} 0 R`).join(' ');
  objects.push(`1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n`);
  objects.push(`2 0 obj\n<< /Type /Pages /Kids [${kids}] /Count ${pages.length} >>\nendobj\n`);
  objects.push(`3 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>\nendobj\n`);
  objects.push(`4 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica-Bold >>\nendobj\n`);
  objects.push(`5 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Courier >>\nendobj\n`);
  pages.forEach((lines, i) => {
    // Page-number footer on multi-page documents (a one-pager stays clean).
    if (pages.length > 1) {
      lines.push({ kind: 'text', x: PAGE_W / 2 - 24, y: MARGIN - 24, size: 8, font: 'F1', text: `Page ${i + 1} of ${pages.length}` });
    }
    const pageNum = firstPageObj + i * 2;
    const contentNum = pageNum + 1;
    objects.push(
      `${pageNum} 0 obj\n<< /Type /Page /Parent 2 0 R /MediaBox [0 0 ${PAGE_W} ${PAGE_H}] ` +
      `/Resources << /Font << /F1 3 0 R /F2 4 0 R /F3 5 0 R >> >> /Contents ${contentNum} 0 R >>\nendobj\n`,
    );
    const stream = lines
      .map(l => {
        if (l.kind === 'text') return `BT /${l.font} ${l.size} Tf 1 0 0 1 ${l.x} ${l.y} Tm (${pdfEscape(l.text)}) Tj ET`;
        // Bar row: label text, then normalized filled rects (q/Q so the gray fill never leaks into text).
        const max = Math.max(1, ...l.values);
        const label = l.label ? `BT /F1 ${l.size} Tf 1 0 0 1 ${l.x} ${l.y + 2} Tm (${pdfEscape(l.label)}) Tj ET\n` : '';
        const bx0 = l.x + (l.label ? Math.min(150, l.label.length * l.size * 0.55 + 12) : 0);
        const rects = l.values.map((v, i) => {
          const h = Math.max(1, Math.round((v / max) * BAR_H));
          return `${bx0 + i * (BAR_W + BAR_GAP)} ${l.y} ${BAR_W} ${h} re f`;