// DatPrintOption.opt memory table, as documented in ESTX_파일구조.md.
function readPrintOptions(buffer, onRow) {
  if (buffer.length < 24 || buffer.readUInt32LE(0) !== 0xbde01996)
    throw Error("인쇄 설정 헤더 오류");
  const count = buffer.readUInt16LE(12),
    rows = buffer.readUInt16LE(14),
    start = buffer.readUInt16LE(22);
  if (count > 1024 || rows > 1000 || start > buffer.length) throw Error("인쇄 설정 크기 오류");
  const decoder = new TextDecoder("euc-kr", { fatal: true });
  let at = 24;
  const take = (n) => {
    if (n < 0 || at + n > buffer.length) throw Error("인쇄 설정 범위 오류");
    const result = buffer.subarray(at, at + n);
    at += n;
    return result;
  };
  const byte = () => take(1)[0];
  const short = () => take(2).readUInt16LE();
  const fields = [];
  for (let i = 0; i < count; i++) {
    const name = take(byte()).toString("ascii"),
      width = short(),
      kind = short();
    take(2);
    const attributes = short();
    for (let j = 0; j < attributes; j++) {
      take(byte());
      const size = short(),
        type = short();
      if (type === 73) take(short());
      else take(size);
    }
    if (!/^[A-Za-z][A-Za-z0-9_]*$/.test(name)) throw Error("인쇄 설정 필드명 오류");
    fields.push({ name, width, kind });
  }
  if (at > start) throw Error("인쇄 설정 설명자 범위 오류");
  at = start;
  const result = [];
  for (let r = 0; r < rows; r++) {
    take(1);
    const status = take(Math.ceil(count / 4)),
      row = {},
      positions = {};
    for (let i = 0; i < count; i++) {
      const { name, width, kind } = fields[i],
        state = (status[i >> 2] >> ((i % 4) * 2)) & 3;
      if (state === 1 || state === 2) continue;
      if (state !== 0) throw Error("인쇄 설정 필드 상태 오류");
      if (["PrintTop", "PrintBottom", "PrintLeft", "PrintRight", "PrintLineCount"].includes(name))
        positions[name] = { at, kind, width };
      if (kind === 1 && width === 4) row[name] = take(4).readInt32LE();
      else if (kind === 3 && width === 2) row[name] = take(2).readInt16LE();
      else if (kind === 4 && width === 8) row[name] = take(8).readDoubleLE();
      else if (kind === 73 && width === 1) row[name] = decoder.decode(take(byte()));
      else if (kind === 75 && width === 4) take(take(4).readUInt32LE());
      else throw Error(`인쇄 설정 필드형 오류: ${name}/${kind}/${width}`);
    }
    result.push(row);
    if (onRow) onRow(row, positions);
  }
  if (at !== buffer.length) throw Error("인쇄 설정 잔여 데이터 오류");
  return result;
}
module.exports = { readPrintOptions };