const EstExchange = (() => {
  function xmlText(buffer) {
    const bytes = new Uint8Array(buffer);
    if (bytes[0] === 0xff && bytes[1] === 0xfe)
      return new TextDecoder("utf-16le", { fatal: true }).decode(bytes);
    if (bytes[0] === 0xfe && bytes[1] === 0xff)
      return new TextDecoder("utf-16be", { fatal: true }).decode(bytes);
    const header = new TextDecoder("ascii").decode(bytes.slice(0, 250)),
      declared = header.match(/encoding\s*=\s*["']([^"']+)["']/i)?.[1]?.toLowerCase() || "utf-8",
      encoding = ["cp949", "ks_c_5601-1987", "euc-kr", "ms949"].includes(declared)
        ? "euc-kr"
        : declared;
    if (!["utf-8", "utf8", "euc-kr", "utf-16", "utf-16le", "utf-16be"].includes(encoding))
      throw Error("지원하지 않는 XML 인코딩: " + encoding);
    return new TextDecoder(encoding, { fatal: true }).decode(bytes);
  }
  function parse(source) {
    if (/<!DOCTYPE|<!ENTITY/i.test(source)) throw Error("XML 외부 선언은 허용하지 않습니다.");
    const doc = new DOMParser().parseFromString(source, "application/xml");
    if (doc.querySelector("parsererror")) throw Error("XML 구문 오류");
    return doc;
  }
  function read(files) {
    const workbook = parse(files["xl/workbook.xml"]),
      rels = parse(files["xl/_rels/workbook.xml.rels"]);
    const shared = files["xl/sharedStrings.xml"]
      ? [...parse(files["xl/sharedStrings.xml"]).getElementsByTagNameNS("*", "si")].map((si) =>
          [...si.getElementsByTagNameNS("*", "t")].map((t) => t.textContent).join(""),
        )
      : [];
    const tables = {};
    for (const sheet of workbook.getElementsByTagNameNS("*", "sheet")) {
      const name = sheet.getAttribute("name");
      if (!EstNative.empty().tables[name] || name.startsWith("Cad")) continue;
      const id = sheet.getAttributeNS(
          "http://schemas.openxmlformats.org/officeDocument/2006/relationships",
          "id",
        ),
        rel = [...rels.getElementsByTagNameNS("*", "Relationship")].find(
          (r) => r.getAttribute("Id") === id,
        ),
        target = rel?.getAttribute("Target") || "";
      const path = target.startsWith("/") ? target.slice(1) : "xl/" + target;
      if (!files[path]) throw Error(`Excel 시트 파일 없음: ${name}`);
      const rows = [...parse(files[path]).getElementsByTagNameNS("*", "row")]
        .map((row) => {
          const values = [];
          for (const cell of row.getElementsByTagNameNS("*", "c")) {
            const address = cell.getAttribute("r") || "",
              letters = address.match(/^[A-Z]+/)?.[0];
            if (!letters) throw Error("Excel 셀 주소 오류");
            const at = [...letters].reduce((n, c) => n * 26 + c.charCodeAt(0) - 64, 0) - 1;
            if (at >= 16384) throw Error("Excel 열 범위 오류");
            if (cell.getElementsByTagNameNS("*", "f").length)
              throw Error(`${name} ${address}: 수식은 Excel에서 값으로 붙여넣은 뒤 가져오세요.`);
            const type = cell.getAttribute("t"),
              v = cell.getElementsByTagNameNS("*", "v")[0]?.textContent;
            let value;
            if (type === "s") {
              value = shared[Number(v)];
              if (value == null) throw Error("Excel 공유 문자열 오류");
            } else if (type === "inlineStr")
              value = [...cell.getElementsByTagNameNS("*", "t")].map((t) => t.textContent).join("");
            else if (type === "b") value = v === "1";
            else if (type === "e") throw Error(`${name} ${address}: Excel 오류값`);
            else if (type === "str") value = v || "";
            else if (v != null) {
              value = Number(v);
              if (!Number.isFinite(value)) throw Error("Excel 숫자 오류");
            }
            values[at] = value;
          }
          return values;
        })
        .filter((row) => row.some((v) => v != null));
      const headers = rows.shift() || [];
      if (
        !headers.length ||
        headers.some(
          (k) =>
            typeof k !== "string" ||
            !/^[A-Za-z][A-Za-z0-9_]*$/.test(k) ||
            ["constructor", "prototype"].includes(k),
        ) ||
        new Set(headers).size !== headers.length
      )
        throw Error(`${name}: 필드명 행이 올바르지 않습니다.`);
      tables[name] = rows.map((values) =>
        Object.fromEntries(headers.map((k, i) => [k, values[i] ?? null])),
      );
    }
    if (!Object.keys(tables).length)
      throw Error("가져올 EST 표 이름이 없습니다. 이 앱에서 내보낸 Excel 표를 사용하세요.");
    return tables;
  }
  function apply(project, tables) {
    const next = structuredClone(project);
    for (const [table, rows] of Object.entries(tables)) {
      const old = next.tables[table],
        byId = new Map(old.filter((r) => r.PkID != null).map((r) => [r.PkID, r]));
      const keys = rows[0] ? Object.keys(rows[0]) : [];
      if (
        !keys.includes("PkID") &&
        old.some((r) => Object.values(r).some((v) => v && typeof v === "object"))
      )
        throw Error(`${table}: 바이너리를 보존하려면 PkID 열이 필요합니다.`);
      const seen = new Set();
      next.tables[table] = rows.map((row) => {
        if (row.PkID != null) {
          if (seen.has(row.PkID)) throw Error(`${table}: PkID 중복`);
          seen.add(row.PkID);
        }
        const previous = byId.get(row.PkID);
        // Keep original blobs and fields deliberately omitted from the workbook.
        const merged = { ...previous, ...row };
        if (["StuffcDat", "LaborcDat", "SilJukDat", "EstiMateDat"].includes(table)) {
          if (
            previous &&
            row.TC !== previous.TC &&
            (row.InputTC ?? previous.InputTC) === previous.InputTC
          ) {
            merged.InputTC = row.TC;
            merged.ValueIndex = 4;
          }
          for (const component of ["NC", "GC", "JC", "SC"])
            if (
              previous &&
              row[component] !== previous[component] &&
              (row["Input" + component] ?? previous["Input" + component]) ===
                previous["Input" + component]
            )
              merged["Input" + component] = row[component];
          if (
            !previous ||
            Object.keys(row).some((key) => (row[key] ?? null) !== (previous[key] ?? null))
          )
            next.options.SourceRefresh = true;
        }
        for (const key of keys)
          if (previous?.[key] && typeof previous[key] === "object") merged[key] = previous[key];
        if (Object.hasOwn(row, "Code") && (previous?.Code ?? "") !== (row.Code ?? "") && previous)
          throw Error("Excel에서 기존 코드를 바꿀 수 없습니다. 앱의 코드 편집을 사용하세요.");
        return merged;
      });
    }
    return EstModel.validate(next);
  }
  async function exportExcel() {
    document.activeElement?.blur();
    const response = await fetch("/api/export-xlsx", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(EstApp.state.project),
    });
    if (!response.ok) throw Error((await response.json()).error);
    EstApp.download(
      `${EstApp.state.project.name}.xlsx`,
      await response.blob(),
      "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    );
  }
  async function exportNative() {
    document.activeElement?.blur();
    const response = await fetch("/api/export-estx", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(EstApp.state.project),
    });
    if (!response.ok) throw Error((await response.json()).error);
    EstApp.download(
      `${EstApp.state.project.name}_edited.estx`,
      await response.blob(),
      "application/octet-stream",
    );
  }
  async function exportJdl() {
    document.activeElement?.blur();
    const project = EstApp.state.project,
      out = await EstApp.api("/api/export-jdl", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(project),
      });
    if (!confirm(out.warnings.slice(0, 15).join("\n") + "\nJDL 기본 표로 내보낼까요?")) return;
    EstApp.download(
      `${project.name}.jdl`,
      Uint8Array.from(atob(out.data), (c) => c.charCodeAt(0)),
      "application/octet-stream",
    );
  }
  function install() {
    const jdlInput = document.createElement("input");
    jdlInput.type = "file";
    jdlInput.accept = ".jdl";
    jdlInput.hidden = true;
    jdlInput.id = "jdl-file";
    document.body.append(jdlInput);
    jdlInput.addEventListener("change", async () => {
      const file = jdlInput.files[0],
        key = EstApp.state.documentKey,
        revision = EstApp.state.revision;
      if (!file) return;
      try {
        const next = await EstApp.api("/api/import-jdl", {
          method: "POST",
          body: await file.arrayBuffer(),
        });
        if (key !== EstApp.state.documentKey || revision !== EstApp.state.revision)
          throw Error("작업이 변경되었습니다. 다시 불러오세요.");
        if (confirm("현재 작업 대신 JDL 내역서를 여시겠습니까?")) EstApp.setProject(next);
      } catch (error) {
        EstApp.state.notice = error.message;
        EstApp.render();
      } finally {
        jdlInput.value = "";
      }
    });
    const xmlInput = document.createElement("input");
    xmlInput.type = "file";
    xmlInput.accept = ".xml";
    xmlInput.hidden = true;
    xmlInput.id = "xml-file";
    document.body.append(xmlInput);
    xmlInput.addEventListener("change", async () => {
      const file = xmlInput.files[0],
        key = EstApp.state.documentKey,
        revision = EstApp.state.revision;
      if (!file) return;
      try {
        const next = EstC3r.read(xmlText(await file.arrayBuffer()));
        if (key !== EstApp.state.documentKey || revision !== EstApp.state.revision)
          throw Error("작업이 변경되었습니다. 다시 불러오세요.");
        if (confirm("현재 작업 대신 XML 내역서를 여시겠습니까?")) EstApp.setProject(next);
      } catch (error) {
        EstApp.state.notice = error.message;
        EstApp.render();
      } finally {
        xmlInput.value = "";
      }
    });
    const input = document.createElement("input");
    input.type = "file";
    input.accept = ".xlsx";
    input.hidden = true;
    input.id = "excel-file";
    document.body.append(input);
    input.addEventListener("change", async () => {
      const file = input.files[0];
      if (!file) return;
      const key = EstApp.state.documentKey,
        revision = EstApp.state.revision;
      try {
        const files = await EstApp.api("/api/import-xlsx", {
            method: "POST",
            body: await file.arrayBuffer(),
          }),
          tables = read(files);
        if (key !== EstApp.state.documentKey || revision !== EstApp.state.revision)
          throw Error("작업이 변경되었습니다. Excel을 다시 불러오세요.");
        const next = apply(EstApp.state.project, tables);
        if (
          !confirm(
            `${Object.entries(tables)
              .map(([name, rows]) => `${EstApp.titles[name] || name}: ${rows.length}행`)
              .join("\n")}\n현재 작업의 해당 표를 교체합니다.`,
          )
        )
          return;
        EstApp.change(() => (EstApp.state.project = next));
      } catch (error) {
        EstApp.state.notice = error.message;
        EstApp.render();
      } finally {
        input.value = "";
      }
    });
  }
  return { read, apply, exportExcel, exportNative, exportJdl, install };
})();