#!/usr/bin/env node
/**
 * Erzeugt aus DSGVO-Dokumentation.md eine PDF-Datei.
 * Verwendung: node generate-dsgvo-pdf.js
 */

const PDFDocument = require('pdfkit');
const fs = require('fs');
const path = require('path');

const MARGIN = 50;
const PAGE_WIDTH = 595; // A4
const CONTENT_WIDTH = PAGE_WIDTH - 2 * MARGIN;

function stripBold(text) {
  return text.replace(/\*\*([^*]+)\*\*/g, '$1');
}

function isTableRow(line) {
  return /^\|.+\|$/.test(line.trim()) && !/^[\s|:-]+$/.test(line.replace(/\s/g, ''));
}

function parseTableRows(lines, startIndex) {
  const rows = [];
  let i = startIndex;
  while (i < lines.length && isTableRow(lines[i])) {
    const line = lines[i];
    if (/^[\s|:-]+$/.test(line.replace(/\s/g, ''))) {
      i++;
      continue; // separator line
    }
    const cells = line.split('|').slice(1, -1).map(c => c.trim());
    if (cells.some(c => c)) rows.push(cells);
    i++;
  }
  return { rows, nextIndex: i };
}

function writeText(doc, text, options = {}) {
  const opts = { width: CONTENT_WIDTH, ...options };
  doc.text(text, opts);
}

function addParagraph(doc, line, fontSize = 10) {
  doc.fontSize(fontSize).font('Helvetica');
  const text = stripBold(line.trim());
  if (!text) return;
  writeText(doc, text);
  doc.moveDown(0.5);
}

function addBullet(doc, line, fontSize = 10) {
  doc.fontSize(fontSize).font('Helvetica');
  const text = stripBold(line.replace(/^[-*]\s*/, '').trim());
  if (!text) return;
  doc.text('• ', { continued: true });
  doc.text(text, { width: CONTENT_WIDTH - 20 });
  doc.moveDown(0.4);
}

function addTable(doc, rows, fontSize = 9) {
  if (rows.length === 0) return;
  const colCount = rows[0].length;
  const colWidth = CONTENT_WIDTH / colCount;
  const rowHeight = fontSize * 1.4;
  const startY = doc.y;

  doc.fontSize(fontSize);
  rows.forEach((row, rowIndex) => {
    const isHeader = rowIndex === 0;
    if (isHeader) doc.font('Helvetica-Bold');
    if (doc.y > 750) {
      doc.addPage();
      doc.y = MARGIN;
    }
    let x = MARGIN;
    row.forEach((cell, cellIndex) => {
      doc.text(cell, x, doc.y, { width: colWidth - 4, align: 'left' });
      x += colWidth;
    });
    doc.y += rowHeight;
    if (isHeader) doc.font('Helvetica');
  });
  doc.moveDown(0.5);
}

function generateDSGVOPdf() {
  const mdPath = path.join(__dirname, 'DSGVO-Dokumentation.md');
  const outPath = path.join(__dirname, 'DSGVO-Dokumentation.pdf');

  if (!fs.existsSync(mdPath)) {
    console.error('Datei nicht gefunden: DSGVO-Dokumentation.md');
    process.exit(1);
  }

  const content = fs.readFileSync(mdPath, 'utf8');
  const lines = content.split(/\r?\n/);

  const doc = new PDFDocument({ margin: MARGIN, size: 'A4' });
  const stream = fs.createWriteStream(outPath);
  doc.pipe(stream);

  let i = 0;
  while (i < lines.length) {
    const line = lines[i];
    const trimmed = line.trim();

    // Neue Seite wenn nötig
    if (doc.y > 750) doc.addPage();

    if (trimmed.startsWith('# ')) {
      doc.fontSize(22).font('Helvetica-Bold');
      writeText(doc, trimmed.slice(2).trim(), { align: 'center' });
      doc.moveDown(0.5);
      doc.fontSize(12).text('Stundenerfassungssystem', { align: 'center' });
      doc.moveDown(1);
      doc.font('Helvetica');
      i++;
      continue;
    }

    if (trimmed.startsWith('## ')) {
      doc.fontSize(16).font('Helvetica-Bold');
      writeText(doc, trimmed.slice(3).trim());
      doc.moveDown(0.5);
      doc.font('Helvetica').fontSize(10);
      i++;
      continue;
    }

    if (trimmed.startsWith('### ')) {
      doc.fontSize(13).font('Helvetica-Bold');
      writeText(doc, trimmed.slice(4).trim());
      doc.moveDown(0.4);
      doc.font('Helvetica').fontSize(10);
      i++;
      continue;
    }

    if (trimmed === '---') {
      doc.moveDown(0.5);
      i++;
      continue;
    }

    if (isTableRow(line)) {
      const { rows, nextIndex } = parseTableRows(lines, i);
      addTable(doc, rows);
      i = nextIndex;
      continue;
    }

    if (trimmed.startsWith('- ') || trimmed.startsWith('* ')) {
      addBullet(doc, trimmed);
      i++;
      continue;
    }

    if (trimmed) {
      addParagraph(doc, trimmed);
    } else {
      doc.moveDown(0.3);
    }
    i++;
  }

  doc.end();
  stream.on('finish', () => {
    console.log('PDF erstellt: ' + outPath);
  });
  stream.on('error', (err) => {
    console.error('Fehler beim Schreiben der PDF:', err);
    process.exit(1);
  });
}

generateDSGVOPdf();