#!/usr/bin/env node

import { createHash } from "node:crypto";
import { mkdir, readFile, rename, writeFile } from "node:fs/promises";
import path from "node:path";
import { inflateRawSync } from "node:zlib";

/**
 * @file scripts/sync-korean-stocks.mjs
 * @description KIS 종목 마스터 파일(KOSPI/KOSDAQ)로 검색 인덱스 JSON을 자동 갱신합니다.
 */

const OUTPUT_FILE_PATH = path.resolve(
  process.cwd(),
  "features/trade/data/korean-stocks.json",
);

const SOURCE_CONFIGS = [
  {
    market: "KOSPI",
    tailWidth: 228,
    url: "https://new.real.download.dws.co.kr/common/master/kospi_code.mst.zip",
  },
  {
    market: "KOSDAQ",
    tailWidth: 222,
    url: "https://new.real.download.dws.co.kr/common/master/kosdaq_code.mst.zip",
  },
];

const MIN_EXPECTED_TOTAL = 3000;
const MIN_EXPECTED_PER_MARKET = 1000;

/**
 * CLI 진입점
 * @see scripts/sync-korean-stocks.mjs main() 종목 인덱스 갱신 파이프라인을 실행합니다.
 */
async function main() {
  const options = parseCliArgs(process.argv.slice(2));

  if (options.help) {
    printHelp();
    return;
  }

  const allItems = [];
  for (const source of SOURCE_CONFIGS) {
    const zipBuffer = await downloadBinary(source.url);
    const { fileName, data } = extractFirstZipEntry(zipBuffer);
    const parsed = parseMasterRows(data, source.market, source.tailWidth);
    console.log(
      `[sync:stocks] ${source.market} parsed ${parsed.length} rows from ${fileName}`,
    );
    allItems.push(...parsed);
  }

  const normalized = normalizeItems(allItems);
  validateCounts(normalized);

  const nextJson = `${JSON.stringify(normalized, null, 2)}\n`;
  const nextHash = sha256(nextJson);

  if (options.dryRun) {
    console.log(`[sync:stocks] dry-run complete, rows=${normalized.length}, hash=${nextHash}`);
    return;
  }

  if (options.check) {
    const currentJson = await readFile(OUTPUT_FILE_PATH, "utf8").catch(() => "");
    const currentHash = sha256(currentJson);
    if (currentJson !== nextJson) {
      console.error(
        `[sync:stocks] out-of-date: current=${currentHash}, next=${nextHash}`,
      );
      console.error("[sync:stocks] run `npm run sync:stocks` to update.");
      process.exitCode = 1;
      return;
    }

    console.log(`[sync:stocks] up-to-date, rows=${normalized.length}, hash=${currentHash}`);
    return;
  }

  await writeFileAtomically(OUTPUT_FILE_PATH, nextJson);
  console.log(`[sync:stocks] updated ${OUTPUT_FILE_PATH}`);
  console.log(`[sync:stocks] rows=${normalized.length}, hash=${nextHash}`);
}

/**
 * CLI 인자 파서
 * @see scripts/sync-korean-stocks.mjs main() 실행 모드를 결정합니다.
 */
function parseCliArgs(args) {
  return {
    check: args.includes("--check"),
    dryRun: args.includes("--dry-run"),
    help: args.includes("--help") || args.includes("-h"),
  };
}

/**
 * 도움말 출력
 * @see scripts/sync-korean-stocks.mjs parseCliArgs() 전달된 옵션을 안내합니다.
 */
function printHelp() {
  console.log("Usage: node scripts/sync-korean-stocks.mjs [--check] [--dry-run]");
  console.log("");
  console.log("Options:");
  console.log("  --check    compare generated JSON with current file and exit 1 on diff");
  console.log("  --dry-run  parse and validate data without writing output");
  console.log("  -h, --help show this help message");
}

/**
 * 원격 바이너리 다운로드
 * @see scripts/sync-korean-stocks.mjs main() KIS 마스터 ZIP 파일을 가져옵니다.
 */
async function downloadBinary(url) {
  const response = await fetch(url, {
    headers: {
      "user-agent": "auto-trade-stock-sync/1.0",
    },
  });

  if (!response.ok) {
    throw new Error(`Failed to download ${url} (${response.status} ${response.statusText})`);
  }

  const arrayBuffer = await response.arrayBuffer();
  return Buffer.from(arrayBuffer);
}

/**
 * ZIP 첫 번째 엔트리 추출
 * @see scripts/sync-korean-stocks.mjs main() ZIP에서 .mst 본문을 읽어옵니다.
 */
function extractFirstZipEntry(zipBuffer) {
  const eocdOffset = findEndOfCentralDirectory(zipBuffer);
  const totalEntries = zipBuffer.readUInt16LE(eocdOffset + 10);
  const centralDirectoryOffset = zipBuffer.readUInt32LE(eocdOffset + 16);

  if (totalEntries < 1) {
    throw new Error("ZIP has no entries.");
  }

  const cdSignature = zipBuffer.readUInt32LE(centralDirectoryOffset);
  if (cdSignature !== 0x02014b50) {
    throw new Error("Invalid central directory signature.");
  }

  const method = zipBuffer.readUInt16LE(centralDirectoryOffset + 10);
  const compressedSize = zipBuffer.readUInt32LE(centralDirectoryOffset + 20);
  const uncompressedSize = zipBuffer.readUInt32LE(centralDirectoryOffset + 24);
  const fileNameLength = zipBuffer.readUInt16LE(centralDirectoryOffset + 28);
  const extraLength = zipBuffer.readUInt16LE(centralDirectoryOffset + 30);
  const commentLength = zipBuffer.readUInt16LE(centralDirectoryOffset + 32);
  const localHeaderOffset = zipBuffer.readUInt32LE(centralDirectoryOffset + 42);
  const fileNameStart = centralDirectoryOffset + 46;
  const fileNameEnd = fileNameStart + fileNameLength;
  const fileName = zipBuffer.subarray(fileNameStart, fileNameEnd).toString("utf8");

  const _unused = extraLength + commentLength;
  void _unused;

  const localSignature = zipBuffer.readUInt32LE(localHeaderOffset);
  if (localSignature !== 0x04034b50) {
    throw new Error("Invalid local header signature.");
  }

  const localNameLength = zipBuffer.readUInt16LE(localHeaderOffset + 26);
  const localExtraLength = zipBuffer.readUInt16LE(localHeaderOffset + 28);
  const dataStart = localHeaderOffset + 30 + localNameLength + localExtraLength;
  const dataEnd = dataStart + compressedSize;
  const compressedData = zipBuffer.subarray(dataStart, dataEnd);

  let data;
  if (method === 0) {
    data = compressedData;
  } else if (method === 8) {
    data = inflateRawSync(compressedData);
  } else {
    throw new Error(`Unsupported ZIP compression method: ${method}`);
  }

  if (uncompressedSize !== 0 && data.length !== uncompressedSize) {
    throw new Error(
      `Uncompressed size mismatch for ${fileName}: expected=${uncompressedSize}, actual=${data.length}`,
    );
  }

  return { fileName, data };
}

/**
 * EOCD(End Of Central Directory) 오프셋 탐색
 * @see scripts/sync-korean-stocks.mjs extractFirstZipEntry() ZIP 중앙 디렉터리 위치를 찾습니다.
 */
function findEndOfCentralDirectory(zipBuffer) {
  const minOffset = Math.max(0, zipBuffer.length - 65557);
  for (let i = zipBuffer.length - 22; i >= minOffset; i -= 1) {
    if (zipBuffer.readUInt32LE(i) === 0x06054b50) {
      return i;
    }
  }
  throw new Error("EOCD signature not found in ZIP.");
}

/**
 * .mst 텍스트 파싱
 * @see scripts/sync-korean-stocks.mjs main() symbol/name/standardCode를 추출합니다.
 */
function parseMasterRows(mstBuffer, market, tailWidth) {
  const decoder = new TextDecoder("euc-kr");
  const text = decoder.decode(mstBuffer);
  const lines = text.split(/\r?\n/);
  const items = [];

  for (const rawLine of lines) {
    const line = rawLine.trimEnd();
    if (!line) continue;
    if (line.length <= tailWidth + 21) continue;

    const part1 = line.slice(0, line.length - tailWidth);
    const symbol = part1.slice(0, 9).trim();
    const standardCode = part1.slice(9, 21).trim();
    const name = part1.slice(21).trim();

    if (!/^\d{6}$/.test(symbol)) continue;
    if (!standardCode || !name) continue;

    items.push({
      symbol,
      name,
      market,
      standardCode,
    });
  }

  return items;
}

/**
 * 아이템 정규화/중복 제거/정렬
 * @see scripts/sync-korean-stocks.mjs main() 검색 인덱스 최종 포맷을 만듭니다.
 */
function normalizeItems(items) {
  const uniqueBySymbol = new Map();

  for (const item of items) {
    const existing = uniqueBySymbol.get(item.symbol);
    if (!existing) {
      uniqueBySymbol.set(item.symbol, item);
      continue;
    }

    const same =
      existing.market === item.market &&
      existing.name === item.name &&
      existing.standardCode === item.standardCode;

    if (!same) {
      throw new Error(
        `Duplicate symbol conflict (${item.symbol}): ${JSON.stringify(existing)} <> ${JSON.stringify(item)}`,
      );
    }
  }

  return [...uniqueBySymbol.values()].sort((a, b) => {
    const bySymbol = a.symbol.localeCompare(b.symbol);
    if (bySymbol !== 0) return bySymbol;
    return a.market.localeCompare(b.market);
  });
}

/**
 * 기본 품질 검증
 * @see scripts/sync-korean-stocks.mjs main() 비정상적으로 적은 데이터면 실패 처리합니다.
 */
function validateCounts(items) {
  if (items.length < MIN_EXPECTED_TOTAL) {
    throw new Error(
      `Total row count is too small: ${items.length} < ${MIN_EXPECTED_TOTAL}`,
    );
  }

  const marketCount = items.reduce(
    (acc, item) => {
      acc[item.market] += 1;
      return acc;
    },
    { KOSPI: 0, KOSDAQ: 0 },
  );

  if (marketCount.KOSPI < MIN_EXPECTED_PER_MARKET) {
    throw new Error(
      `KOSPI row count is too small: ${marketCount.KOSPI} < ${MIN_EXPECTED_PER_MARKET}`,
    );
  }

  if (marketCount.KOSDAQ < MIN_EXPECTED_PER_MARKET) {
    throw new Error(
      `KOSDAQ row count is too small: ${marketCount.KOSDAQ} < ${MIN_EXPECTED_PER_MARKET}`,
    );
  }
}

/**
 * 원자적 파일 저장
 * @see scripts/sync-korean-stocks.mjs main() 저장 도중 파일 손상을 방지합니다.
 */
async function writeFileAtomically(targetPath, content) {
  const dir = path.dirname(targetPath);
  const tempPath = path.join(
    dir,
    `.${path.basename(targetPath)}.${process.pid}.${Date.now()}.tmp`,
  );

  await mkdir(dir, { recursive: true });
  await writeFile(tempPath, content, "utf8");
  await rename(tempPath, targetPath);
}

/**
 * SHA-256 해시
 * @see scripts/sync-korean-stocks.mjs main() 변경 여부를 간단히 비교합니다.
 */
function sha256(value) {
  return createHash("sha256").update(value).digest("hex");
}

main().catch((error) => {
  console.error(`[sync:stocks] ${error instanceof Error ? error.message : String(error)}`);
  process.exit(1);
});