const { pack, unpack } = require("./archive.cjs");
const xml = (value) =>
  String(value ?? "").replace(
    /[&<>"']/g,
    (c) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&apos;" })[c],
  );
const column = (index) => {
  let name = "";
  for (index++; index; index = Math.floor((index - 1) / 26))
    name = String.fromCharCode(65 + ((index - 1) % 26)) + name;
  return name;
};
function sheet(rows) {
  if (rows.length > 1048576 || rows.some((r) => r.length > 16384))
    throw Error("Excel 행/열 한도 초과");
  return `<?xml version="1.0" encoding="UTF-8"?><worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"><sheetViews><sheetView workbookViewId="0"><pane ySplit="1" topLeftCell="A2" state="frozen"/></sheetView></sheetViews><sheetData>${rows
    .map(
      (r, i) =>
        `<row r="${i + 1}">${r
          .map((v, j) => {
            const ref = column(j) + (i + 1);
            if (v == null) return "";
            if (typeof v === "number") {
              if (!Number.isFinite(v)) throw Error("유효하지 않은 Excel 숫자");
              return `<c r="${ref}"><v>${v}</v></c>`;
            }
            if (typeof v === "boolean") return `<c r="${ref}" t="b"><v>${v ? 1 : 0}</v></c>`;
            const text = typeof v === "object" ? JSON.stringify(v) : String(v);
            if (text.length > 32767) throw Error("Excel 셀 문자 한도 초과: " + ref);
            return `<c r="${ref}" t="inlineStr"><is><t xml:space="preserve">${xml(text)}</t></is></c>`;
          })
          .join("")}</row>`,
    )
    .join("")}</sheetData><pageSetup paperSize="9" orientation="landscape"/></worksheet>`;
}
function workbook(project) {
  const files = new Map(),
    sheets = [];
  for (const [name, rows] of Object.entries(project.tables)) {
    if (!Array.isArray(rows) || name.startsWith("Cad") || name.length > 31) continue;
    // Binary originals stay in JSON/ESTX; Excel edits scalar table fields only.
    const keys = [
      ...new Set(
        rows.flatMap((r) =>
          Object.keys(r).filter(
            (k) => !k.startsWith("_") && r[k] != null && typeof r[k] !== "object",
          ),
        ),
      ),
    ];
    if (!keys.length) continue;
    sheets.push({
      name,
      rows: [
        keys,
        ...rows.map((r) =>
          keys.map((k) => (typeof r[k] === "object" && r[k] != null ? null : r[k])),
        ),
      ],
    });
  }
  sheets.unshift({
    name: "공사정보",
    rows: [
      ["항목", "값"],
      ["공사명", project.name],
      ["형식", "est-web-xlsx-1"],
      ["설명", "표의 첫 행은 필드명입니다. 바이너리는 포함하지 않습니다."],
    ],
  });
  sheets.forEach((s, i) => files.set(`xl/worksheets/sheet${i + 1}.xml`, sheet(s.rows)));
  const ns = "http://schemas.openxmlformats.org/";
  files.set(
    "[Content_Types].xml",
    `<?xml version="1.0"?><Types xmlns="${ns}package/2006/content-types"><Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/><Default Extension="xml" ContentType="application/xml"/><Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/>${sheets.map((s, i) => `<Override PartName="/xl/worksheets/sheet${i + 1}.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/>`).join("")}</Types>`,
  );
  files.set(
    "_rels/.rels",
    `<?xml version="1.0"?><Relationships xmlns="${ns}package/2006/relationships"><Relationship Id="rId1" Type="${ns}officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/></Relationships>`,
  );
  files.set(
    "xl/workbook.xml",
    `<?xml version="1.0" encoding="UTF-8"?><workbook xmlns="${ns}spreadsheetml/2006/main" xmlns:r="${ns}officeDocument/2006/relationships"><sheets>${sheets.map((s, i) => `<sheet name="${xml(s.name)}" sheetId="${i + 1}" r:id="rId${i + 1}"/>`).join("")}</sheets><calcPr calcId="0" fullCalcOnLoad="1"/></workbook>`,
  );
  files.set(
    "xl/_rels/workbook.xml.rels",
    `<?xml version="1.0"?><Relationships xmlns="${ns}package/2006/relationships">${sheets.map((s, i) => `<Relationship Id="rId${i + 1}" Type="${ns}officeDocument/2006/relationships/worksheet" Target="worksheets/sheet${i + 1}.xml"/>`).join("")}</Relationships>`,
  );
  return pack(files);
}
function readWorkbook(bytes) {
  const files = unpack(bytes),
    selected = {};
  if (!files.has("xl/workbook.xml") || !files.has("xl/_rels/workbook.xml.rels"))
    throw Error("Excel 통합문서 구조 없음");
  for (const [name, data] of files)
    if (
      name === "xl/workbook.xml" ||
      name === "xl/_rels/workbook.xml.rels" ||
      name === "xl/sharedStrings.xml" ||
      /^xl\/worksheets\/[^/]+\.xml$/.test(name)
    )
      selected[name] = data.toString("utf8");
  return selected;
}
module.exports = { workbook, readWorkbook, xml };