import PDFDocument from 'pdfkit';

function addSectionTitle(doc, title) {
  doc.moveDown(0.5);
  doc.fontSize(14).font('Helvetica-Bold').text(title);
  doc.moveDown(0.3);
  doc.fontSize(10).font('Helvetica');
}

function ensurePageSpace(doc, neededHeight = 80) {
  if (doc.y + neededHeight > doc.page.height - doc.page.margins.bottom) {
    doc.addPage();
  }
}

function keyValue(doc, key, value) {
  doc.font('Helvetica-Bold').text(`${key}: `, { continued: true });
  doc.font('Helvetica').text(String(value ?? '-'));
}

function tableRow(doc, cols, widths, opts = {}) {
  const startX = doc.x;
  const y = doc.y;
  const lineHeight = opts.lineHeight || 14;

  let x = startX;
  for (let i = 0; i < cols.length; i++) {
    const text = cols[i] == null ? '-' : String(cols[i]);
    doc.text(text, x, y, {
      width: widths[i],
      lineBreak: false
    });
    x += widths[i];
  }
  doc.y = y + lineHeight;
}

export function generateOrderDossierPdf({ orderId, createdAt, customerName, config, cuttingList, packing }) {
  return new Promise((resolve, reject) => {
    const doc = new PDFDocument({ size: 'A4', margin: 40 });
    const chunks = [];

    doc.on('data', (chunk) => chunks.push(chunk));
    doc.on('end', () => resolve(Buffer.concat(chunks)));
    doc.on('error', reject);

    doc.fontSize(18).font('Helvetica-Bold').text(`Dossier technique commande #${orderId}`);
    doc.fontSize(10).font('Helvetica').text(`Généré le ${new Date().toLocaleString('fr-CH')}`);
    if (createdAt) doc.text(`Commande du ${new Date(createdAt).toLocaleString('fr-CH')}`);
    if (customerName) doc.text(`Client: ${customerName}`);

    addSectionTitle(doc, 'Configuration');
    keyValue(doc, 'Dimensions', `${config.widthMm} x ${config.heightMm} x ${config.depthMm} mm`);
    keyValue(doc, 'Installation', config.installationType === 'niche' ? 'Encastree' : 'Libre');
    keyValue(doc, 'Portes', config.doorType === 'sliding' ? 'Coulissantes' : 'Battantes');
    keyValue(doc, 'Modules', config.moduleCount || 0);

    addSectionTitle(doc, 'Liste de decoupage');
    const cutWidths = [170, 130, 40, 130];
    tableRow(doc, ['Piece', 'L x H x Ep.', 'Qte', 'Finition'], cutWidths, { lineHeight: 16 });
    doc.moveTo(doc.x, doc.y).lineTo(doc.page.width - doc.page.margins.right, doc.y).stroke();
    doc.moveDown(0.2);

    for (const piece of (cuttingList?.pieces || [])) {
      ensurePageSpace(doc, 18);
      tableRow(
        doc,
        [
          piece.description,
          `${piece.widthMm}x${piece.heightMm}x${piece.thicknessMm}`,
          piece.quantity,
          piece.finishLabel || '-'
        ],
        cutWidths
      );
    }

    addSectionTitle(doc, 'Colisage');
    const packWidths = [50, 170, 70, 70];
    tableRow(doc, ['Colis', 'Niveau', 'Poids', 'Pieces'], packWidths, { lineHeight: 16 });
    doc.moveTo(doc.x, doc.y).lineTo(doc.page.width - doc.page.margins.right, doc.y).stroke();
    doc.moveDown(0.2);

    for (const box of (packing?.boxes || [])) {
      ensurePageSpace(doc, 18);
      tableRow(
        doc,
        [
          box.id,
          box.level || '-',
          `${Number(box.totalWeightKg || 0).toFixed(1)} kg`,
          box.pieces?.length || 0
        ],
        packWidths
      );
    }

    doc.end();
  });
}