/**
 * Export Excel (.xlsx) — APEX
 * Génère un classeur OOXML minimal mais valide à partir de la liste de débitage,
 * de la quincaillerie et du calepinage, sans dépendance externe (utilise jszip).
 *
 * Le format .xlsx est une archive ZIP de fichiers XML. On utilise des chaînes
 * "inlineStr" pour éviter la table de chaînes partagées.
 */
import JSZip from 'jszip';

function escapeXml(value) {
  return String(value ?? '')
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&apos;');
}

/** Convertit un index de colonne 0-based en lettre Excel (0 -> A, 26 -> AA). */
function colLetter(index) {
  let n = index;
  let s = '';
  do {
    s = String.fromCharCode(65 + (n % 26)) + s;
    n = Math.floor(n / 26) - 1;
  } while (n >= 0);
  return s;
}

function cellXml(ref, value, { header = false } = {}) {
  if (value === null || value === undefined || value === '') {
    return `<c r="${ref}"${header ? ' s="1"' : ''}/>`;
  }
  if (typeof value === 'number' && Number.isFinite(value)) {
    return `<c r="${ref}"${header ? ' s="1"' : ''}><v>${value}</v></c>`;
  }
  const styleAttr = header ? ' s="1"' : '';
  return `<c r="${ref}"${styleAttr} t="inlineStr"><is><t xml:space="preserve">${escapeXml(value)}</t></is></c>`;
}

/**
 * @param {{ name:string, columns:string[], rows:Array<Array<string|number>> }} sheet
 */
function sheetXml(sheet) {
  const rowsXml = [];
  // Header row
  const headerCells = sheet.columns
    .map((c, i) => cellXml(`${colLetter(i)}1`, c, { header: true }))
    .join('');
  rowsXml.push(`<row r="1">${headerCells}</row>`);
  // Data rows
  sheet.rows.forEach((row, r) => {
    const cells = row.map((val, i) => cellXml(`${colLetter(i)}${r + 2}`, val)).join('');
    rowsXml.push(`<row r="${r + 2}">${cells}</row>`);
  });

  const colsCount = sheet.columns.length;
  const colsXml = `<cols>${Array.from({ length: colsCount }, (_, i) => `<col min="${i + 1}" max="${i + 1}" width="22" customWidth="1"/>`).join('')}</cols>`;

  return `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
${colsXml}
<sheetData>
${rowsXml.join('\n')}
</sheetData>
</worksheet>`;
}

function contentTypesXml(sheetCount) {
  const overrides = Array.from({ length: sheetCount }, (_, i) =>
    `<Override PartName="/xl/worksheets/sheet${i + 1}.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/>`
  ).join('');
  return `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
<Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>
<Default Extension="xml" ContentType="application/xml"/>
<Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/>
<Override PartName="/xl/styles.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.styles+xml"/>
${overrides}
</Types>`;
}

function workbookXml(sheets) {
  const sheetEls = sheets
    .map((s, i) => `<sheet name="${escapeXml(s.name).slice(0, 31)}" sheetId="${i + 1}" r:id="rId${i + 1}"/>`)
    .join('');
  return `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
<sheets>${sheetEls}</sheets>
</workbook>`;
}

function workbookRelsXml(sheets) {
  const rels = sheets
    .map((_, i) => `<Relationship Id="rId${i + 1}" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet${i + 1}.xml"/>`)
    .join('');
  const stylesRid = sheets.length + 1;
  return `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
${rels}
<Relationship Id="rId${stylesRid}" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles" Target="styles.xml"/>
</Relationships>`;
}

const ROOT_RELS_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
<Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/>
</Relationships>`;

const STYLES_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<styleSheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
<fonts count="2"><font><sz val="11"/><name val="Calibri"/></font><font><b/><sz val="11"/><name val="Calibri"/></font></fonts>
<fills count="3"><fill><patternFill patternType="none"/></fill><fill><patternFill patternType="gray125"/></fill><fill><patternFill patternType="solid"><fgColor rgb="FFE8EAED"/><bgColor indexed="64"/></patternFill></fill></fills>
<borders count="1"><border><left/><right/><top/><bottom/><diagonal/></border></borders>
<cellStyleXfs count="1"><xf numFmtId="0" fontId="0" fillId="0" borderId="0"/></cellStyleXfs>
<cellXfs count="2"><xf numFmtId="0" fontId="0" fillId="0" borderId="0" xfId="0"/><xf numFmtId="0" fontId="1" fillId="2" borderId="0" xfId="0" applyFont="1" applyFill="1"/></cellXfs>
</styleSheet>`;

/**
 * Construit un buffer .xlsx à partir d'une liste de feuilles.
 * @param {Array<{ name:string, columns:string[], rows:Array<Array<string|number>> }>} sheets
 * @returns {Promise<Buffer>}
 */
export async function buildXlsxBuffer(sheets) {
  const zip = new JSZip();
  zip.file('[Content_Types].xml', contentTypesXml(sheets.length));
  zip.file('_rels/.rels', ROOT_RELS_XML);
  zip.file('xl/workbook.xml', workbookXml(sheets));
  zip.file('xl/_rels/workbook.xml.rels', workbookRelsXml(sheets));
  zip.file('xl/styles.xml', STYLES_XML);
  sheets.forEach((s, i) => {
    zip.file(`xl/worksheets/sheet${i + 1}.xml`, sheetXml(s));
  });
  return zip.generateAsync({ type: 'nodebuffer', compression: 'DEFLATE' });
}

/**
 * Construit le classeur Excel de la liste de débitage (+ quincaillerie + calepinage).
 * @param {object} params
 * @param {object} params.cuttingList
 * @param {object} [params.hardware] résultat de generateHardwareList
 * @param {object} [params.cuttingPlan] résultat de generateCuttingPlan
 * @returns {Promise<Buffer>}
 */
export async function buildCuttingListXlsx({ cuttingList, hardware = null, cuttingPlan = null }) {
  const sheets = [];

  // Feuille 1 — Débitage
  const debitColumns = [
    'Finition', 'Pièce', 'L finie (mm)', 'H finie (mm)', 'Ép. (mm)', 'Qté',
    'L brute (mm)', 'H brute (mm)', 'Surcote (mm)', 'Surface (m²)',
    'Chants (côtés)', 'Sens de collage', 'Usinage'
  ];
  const debitRows = [];
  for (const group of (cuttingList?.byFinish || [])) {
    for (const p of (group.pieces || [])) {
      const banding = p.edgeBanding && p.edgeBanding.type !== 'none'
        ? `${p.edgeBanding.sides} côtés`
        : '—';
      const sens = p.edgeBanding?.direction?.label || '—';
      const usinage = p.machining ? Object.keys(p.machining).join(', ') : '—';
      debitRows.push([
        group.finishLabel || '—',
        p.description || '',
        Number(p.widthMm) || 0,
        Number(p.heightMm) || 0,
        Number(p.thicknessMm) || 0,
        Number(p.quantity) || 0,
        Number(p.rawCutWidthMm) || 0,
        Number(p.rawCutHeightMm) || 0,
        Number(p.surcoteMm) || 0,
        Number((p.surfaceM2 || 0).toFixed(3)),
        banding,
        sens,
        usinage
      ]);
    }
  }
  sheets.push({ name: 'Débitage', columns: debitColumns, rows: debitRows });

  // Feuille 2 — Quincaillerie
  if (hardware && Array.isArray(hardware.items) && hardware.items.length) {
    const hwColumns = ['Désignation', 'Référence', 'Qté', 'Prix unitaire (CHF)', 'Total (CHF)'];
    const hwRows = hardware.items.map((it) => [
      it.label || it.name || '',
      it.code || it.reference || '—',
      Number(it.quantity) || 0,
      it.unitPriceChf != null ? Number(it.unitPriceChf) : '—',
      it.lineTotalChf != null ? Number(it.lineTotalChf) : (it.totalChf != null ? Number(it.totalChf) : '—')
    ]);
    sheets.push({ name: 'Quincaillerie', columns: hwColumns, rows: hwRows });
  }

  // Feuille 3 — Calepinage / plan de coupe
  if (cuttingPlan && Array.isArray(cuttingPlan.boards) && cuttingPlan.boards.length) {
    const planColumns = [
      'Panneau', 'Format (mm)', 'Pièces placées', 'Surface utilisée (m²)',
      'Surface panneau (m²)', 'Chute (m²)', 'Chute (%)'
    ];
    const planRows = cuttingPlan.boards.map((b, i) => [
      `Panneau ${i + 1}`,
      `${b.boardWidthMm} x ${b.boardHeightMm}`,
      (b.placements || []).length,
      Number((b.usedAreaM2 || 0).toFixed(3)),
      Number((b.boardAreaM2 || 0).toFixed(3)),
      Number((b.wasteAreaM2 || 0).toFixed(3)),
      Number((b.wastePercent || 0).toFixed(1))
    ]);
    // Ligne de synthèse globale
    planRows.push([
      'TOTAL',
      '',
      cuttingPlan.totalPlacedPieces ?? '',
      Number((cuttingPlan.totalUsedAreaM2 || 0).toFixed(3)),
      Number((cuttingPlan.totalBoardAreaM2 || 0).toFixed(3)),
      Number((cuttingPlan.totalWasteAreaM2 || 0).toFixed(3)),
      Number((cuttingPlan.globalWastePercent || 0).toFixed(1))
    ]);
    sheets.push({ name: 'Calepinage', columns: planColumns, rows: planRows });
  }

  return buildXlsxBuffer(sheets);
}