const fs = require('fs');
const path = require('path');
const { parseAndPrintData } = require('./index');
const {
  extractFramesFromText,
  extractFramesFromUtf16leBuffer,
  guessTextEncodingFromBuffer,
} = require('./framing');

function printUsageAndExit(code) {
  // eslint-disable-next-line no-console
  console.log(`\n用法:\n  node .\\parse_raw.js <file> [--hex|--b64|--bin] [--utf16le|--utf8]\n  node .\\parse_raw.js --demo\n\n说明:\n- <file> 可以是二进制抓包文件，或包含 hex/base64 的文本文件。\n- 默认会尝试自动判断：hex/base64/二进制，以及 utf16le/utf8。\n`);
  process.exit(code);
}

function stripNonHex(text) {
  return text
    .replace(/0x/gi, '')
    .replace(/\\x/gi, '')
    .replace(/[^0-9a-fA-F]/g, '');
}

function looksLikeHex(text) {
  const cleaned = stripNonHex(text);
  return cleaned.length >= 40 && cleaned.length % 2 === 0;
}

function decodeHexText(text) {
  let cleaned = stripNonHex(text);
  if (cleaned.length % 2 !== 0) {
    // eslint-disable-next-line no-console
    console.warn('⚠️ hex 长度不是偶数（可能复制/截断），已丢弃最后 1 个半字节继续尝试解析');
    cleaned = cleaned.slice(0, -1);
  }
  return Buffer.from(cleaned, 'hex');
}

function looksLikeBase64(text) {
  const cleaned = text.replace(/\s+/g, '');
  if (cleaned.length < 40) return false;
  if (cleaned.length % 4 !== 0) return false;
  return /^[A-Za-z0-9+/]+={0,2}$/.test(cleaned);
}

function decodeBase64Text(text) {
  const cleaned = text.replace(/\s+/g, '');
  return Buffer.from(cleaned, 'base64');
}

function autoDecodeFileToBytes(filePath) {
  const buf = fs.readFileSync(filePath);

  // Try treat as UTF-8 text containing hex/base64.
  const asText = buf.toString('utf8');
  if (looksLikeHex(asText)) {
    return { bytes: decodeHexText(asText), source: 'hex' };
  }
  if (looksLikeBase64(asText)) {
    return { bytes: decodeBase64Text(asText), source: 'base64' };
  }

  return { bytes: buf, source: 'binary' };
}

function runParse(bytes, forcedEncoding) {
  const encoding = forcedEncoding || guessTextEncodingFromBuffer(bytes);

  if (encoding === 'utf16le') {
    const { frames } = extractFramesFromUtf16leBuffer(bytes);
    if (frames.length === 0) {
      // 兜底：抓包/复制时常见“消息截断”，导致找不到 </ORU_R31>，但前面可能已经包含完整 OBX 段。
      const iconv = require('iconv-lite');
      let work = bytes;
      if (work.length % 2 === 1) work = work.slice(0, work.length - 1);
      const text = iconv.decode(work, 'utf16le').replace(/^\uFEFF/, '');
      const hasRoot = text.includes('<ORU_R31') || text.includes('<ORF_R04');
      const obxBlocks = text.match(/<OBX>[\s\S]*?<\/OBX>/g) || [];

      if (hasRoot && obxBlocks.length > 0) {
        // eslint-disable-next-line no-console
        console.log(`⚠️ 未找到完整帧（疑似截断），尝试从片段提取 ${obxBlocks.length} 个 OBX 解析`);
        const wrapped = `<?xml version="1.0" encoding="UTF-8"?>\n<ORU_R31>\n  <ORU_R31.OBSERVATION>\n${obxBlocks.join('\n')}\n  </ORU_R31.OBSERVATION>\n</ORU_R31>`;
        parseAndPrintData(wrapped);
        return;
      }

      // eslint-disable-next-line no-console
      console.log('未在 UTF-16LE 流中找到 ORU_R31/ORF_R04 XML 完整帧');
      return;
    }
    // eslint-disable-next-line no-console
    console.log(`找到 ${frames.length} 条 XML 帧 (encoding=utf16le)`);
    frames.forEach((xml, idx) => {
      // eslint-disable-next-line no-console
      console.log(`\n===== Frame #${idx + 1} =====`);
      parseAndPrintData(xml);
    });
    return;
  }

  // utf8
  const text = bytes.toString('utf8');
  const { frames } = extractFramesFromText(text);
  if (frames.length === 0) {
    const hasRoot = text.includes('<ORU_R31') || text.includes('<ORF_R04');
    const obxBlocks = text.match(/<OBX>[\s\S]*?<\/OBX>/g) || [];
    if (hasRoot && obxBlocks.length > 0) {
      // eslint-disable-next-line no-console
      console.log(`⚠️ 未找到完整帧（疑似截断），尝试从片段提取 ${obxBlocks.length} 个 OBX 解析`);
      const wrapped = `<?xml version="1.0" encoding="UTF-8"?>\n<ORU_R31>\n  <ORU_R31.OBSERVATION>\n${obxBlocks.join('\n')}\n  </ORU_R31.OBSERVATION>\n</ORU_R31>`;
      parseAndPrintData(wrapped);
      return;
    }

    // eslint-disable-next-line no-console
    console.log('未在 UTF-8 文本中找到 ORU_R31/ORF_R04 XML 完整帧');
    return;
  }
  // eslint-disable-next-line no-console
  console.log(`找到 ${frames.length} 条 XML 帧 (encoding=utf8)`);
  frames.forEach((xml, idx) => {
    // eslint-disable-next-line no-console
    console.log(`\n===== Frame #${idx + 1} =====`);
    parseAndPrintData(xml);
  });
}

function main() {
  const args = process.argv.slice(2);
  if (args.length === 0) printUsageAndExit(1);

  if (args.includes('--help') || args.includes('-h')) printUsageAndExit(0);

  if (args.includes('--demo')) {
    const demoXml = `<?xml version="1.0" encoding="UTF-8"?>\n<ORU_R31>\n  <MSH><MSH.18>UNICODE</MSH.18></MSH>\n  <ORU_R31.OBSERVATION>\n    <OBX>\n      <OBX.3><CE.1>7</CE.1><CE.2>Temperature</CE.2></OBX.3>\n      <OBX.5><FN.1>37.500000</FN.1></OBX.5>\n      <OBX.6><CE.1>cel</CE.1></OBX.6>\n    </OBX>\n  </ORU_R31.OBSERVATION>\n</ORU_R31>`;

    const iconv = require('iconv-lite');
    const bytes = Buffer.concat([
      iconv.encode(demoXml, 'utf16le'),
      iconv.encode(demoXml, 'utf16le'),
    ]);

    runParse(bytes, 'utf16le');
    return;
  }

  const fileArg = args.find(a => !a.startsWith('--'));
  if (!fileArg) printUsageAndExit(1);

  const filePath = path.resolve(process.cwd(), fileArg);
  if (!fs.existsSync(filePath)) {
    // eslint-disable-next-line no-console
    console.error(`文件不存在: ${filePath}`);
    printUsageAndExit(1);
  }

  const forcedEncoding = args.includes('--utf16le') ? 'utf16le' : (args.includes('--utf8') ? 'utf8' : null);

  let bytes;
  let source;
  try {
    if (args.includes('--hex')) {
      bytes = decodeHexText(fs.readFileSync(filePath, 'utf8'));
      source = 'hex';
    } else if (args.includes('--b64')) {
      bytes = decodeBase64Text(fs.readFileSync(filePath, 'utf8'));
      source = 'base64';
    } else if (args.includes('--bin')) {
      bytes = fs.readFileSync(filePath);
      source = 'binary';
    } else {
      ({ bytes, source } = autoDecodeFileToBytes(filePath));
    }
  } catch (e) {
    // eslint-disable-next-line no-console
    console.error(`解码失败: ${e && e.message ? e.message : String(e)}`);
    printUsageAndExit(1);
  }

  // eslint-disable-next-line no-console
  console.log(`输入: ${filePath} (source=${source}, bytes=${bytes.length})`);

  runParse(bytes, forcedEncoding);
}

main();