const express = require("express");
const net = require("net");

const ABS_HOST = process.env.ABS_HOST || "192.0.0.14";
const ABS_PORT = Number(process.env.ABS_PORT || 7000);

const ABS_POLL = 178;
const LOG = 100;
const LOGBT = 6013;
const BTI = 6014;
const RPI = 6015;
const SUCCESS = 0;

const PKT_SIZE = 512;
const PAYLOAD_PER_PKT = PKT_SIZE - 1;

const DEFAULT_TIMEOUT_MS = Number(process.env.BRIDGE_TIMEOUT_MS || 20000);
const RETRIES = Number(process.env.BRIDGE_RETRIES || 2);
const RETRY_DELAY_MS = Number(process.env.BRIDGE_RETRY_DELAY_MS || 500);

const MAX_VENUES = 10;
const MAX_RACES = 14;
const MAX_POOLS = 8;
const MAX_HORSES = 24;

const app = express();

// Venue and pool mappings
const venueMapping = {
  1: "BLR", 2: "MUM", 3: "MAA", 4: "CAL", 5: "HYD",
  6: "MYS", 7: "OTY", 8: "PUN", 9: "GYM", 10: "OVS"
};

const poolMapping = {
  1: "WNP", 2: "PLP", 3: "SHP", 4: "THP", 5: "QNP",
  6: "FRP", 7: "TNP", 8: "EXP", 9: "TBP", 10: "MJP", 11: "JPP"
};

const multiLegPoolMapping = {
  "T1": "TBP", "T2": "TBP", "T3": "TBP",
  "M1": "MJP", "M2": "MJP", "M3": "MJP",
  "J1": "JPP", "J2": "JPP", "J3": "JPP"
};

function getDateStr(nDate) {
  const s = nDate.toString().padStart(8, "0");
  return `${s.slice(0, 4)}/${s.slice(4, 6)}/${s.slice(6, 8)}`;
}

function getTimeStr(nTime) {
  const s = nTime.toString().padStart(6, "0");
  return `${s.slice(0, 2)}:${s.slice(2, 4)}:${s.slice(4, 6)}`;
}

function getVenueIdStr(nVenue) {
  return venueMapping[nVenue] || "";
}

function getPoolIdStr(nPoolId) {
  return poolMapping[nPoolId] || "";
}

function getMultiLegPoolIdStr(szMultiLegRace) {
  return multiLegPoolMapping[szMultiLegRace] || "";
}

function readJsonBody(req) {
  return new Promise((resolve) => {
    const chunks = [];
    req.on("data", (c) => chunks.push(c));
    req.on("end", () => {
      if (!chunks.length) return resolve({});
      const txt = Buffer.concat(chunks).toString("utf8").trim();
      if (!txt) return resolve({});
      try { resolve(JSON.parse(txt)); } catch { resolve({}); }
    });
  });
}

function writeFixedAscii(buf, offset, s, len) {
  const str = (s ?? "").toString();
  for (let i = 0; i < len; i++) buf[offset + i] = i < str.length ? (str.charCodeAt(i) & 0xff) : 0x00;
  return offset + len;
}

function readFixedAscii(buf, offset, len) {
  let end = offset;
  const max = offset + len;
  while (end < max && buf[end] !== 0) end++;
  const raw = buf.subarray(offset, end).toString("ascii");
  return { value: raw.trimEnd(), next: offset + len };
}

function hexSlice(buf, off, len) {
  const s = Math.max(0, off);
  const e = Math.min(buf.length, off + len);
  return buf.subarray(s, e).toString("hex");
}

function remaining(buf, off) {
  return Math.max(0, buf.length - off);
}

function safeAdvanceOrBreak(buf, off, want, outObj) {
  if (remaining(buf, off) < want) {
    outObj._truncated = true;
    return false;
  }
  return true;
}

function looksLikeHeaderAt(buf, off, expected_nTxnCd = null) {
  if (remaining(buf, off) < 18) return false;
  try {
    const nTxnCd = buf.readInt32LE(off);
    const nRetCd = buf.readInt32LE(off + 4);
    const nNumRecs = buf.readInt32LE(off + 8);
    // Allow nTxnCd: 100 as a fallback for any section, since the server may send it
    const validTxnCd = expected_nTxnCd ? (nTxnCd === expected_nTxnCd || nTxnCd === 100) : (nTxnCd >= 100 && nTxnCd <= 105);
    return validTxnCd && nRetCd >= 0 && nRetCd < 10000 && nNumRecs >= 0 && nNumRecs < 100;
  } catch { return false; }
}

function alignToPossibleHeader(reply, off, expected_nTxnCd = null) {
  // Try current offset and additional offsets for alignment
  const tryOffsets = [0, 2, 4, -4, 8, 12];
  for (const d of tryOffsets) {
    const o = off + d;
    if (o >= 0 && looksLikeHeaderAt(reply, o, expected_nTxnCd)) return o;
  }
  // Fallback: align to valid nRaceDt (20000101–21001231)
  for (const d of tryOffsets) {
    const o = off + d;
    if (o >= 0 && remaining(reply, o) >= 4) {
      const nRaceDt = reply.readInt32LE(o);
      if (nRaceDt >= 20000101 && nRaceDt <= 21001231) return o;
    }
  }
  return off;
}

function adjustForOptionalOp(replyBuf, bodyOffset) {
  if (replyBuf.length >= bodyOffset + 4) {
    const maybeOp = replyBuf.readInt32LE(bodyOffset);
    if (maybeOp === LOGBT || maybeOp === LOG || maybeOp === 0 || (maybeOp >= 100 && maybeOp <= 10000)) {
      return { offset: bodyOffset + 4, extraOp: maybeOp };
    }
  }
  return { offset: bodyOffset, extraOp: null };
}

function absSend(sock, payload) {
  return new Promise((resolve, reject) => {
    let off = 0;
    function sendNext() {
      const remaining = payload.length - off;
      const toCopy = Math.min(PAYLOAD_PER_PKT, Math.max(remaining, 0));
      const pkt = Buffer.alloc(PKT_SIZE, 0);
      pkt[0] = (off + toCopy >= payload.length) ? 48 : 49;
      if (toCopy > 0) payload.copy(pkt, 1, off, off + toCopy);
      off += toCopy;
      sock.write(pkt, (err) => {
        if (err) return reject(err);
        if (pkt[0] === 48) return resolve();
        sendNext();
      });
    }
    if (!payload || payload.length === 0) {
      const pkt = Buffer.alloc(PKT_SIZE, 0);
      pkt[0] = 48;
      sock.write(pkt, (err) => err ? reject(err) : resolve());
    } else {
      sendNext();
    }
  });
}

function absRecv(sock, timeoutMs = DEFAULT_TIMEOUT_MS) {
  return new Promise((resolve, reject) => {
    const chunks = [];
    let buf = Buffer.alloc(0);
    const timer = timeoutMs ? setTimeout(() => done(new Error("TCP timeout")), timeoutMs) : null;

    function done(err) {
      if (timer) clearTimeout(timer);
      sock.off("data", onData);
      if (err) reject(err);
      else resolve(Buffer.concat(chunks));
    }
    function onData(data) {
      buf = Buffer.concat([buf, data]);
      while (buf.length >= PKT_SIZE) {
        const pkt = buf.subarray(0, PKT_SIZE);
        buf = buf.subarray(PKT_SIZE);
        const flag = pkt[0];
        chunks.push(pkt.subarray(1));
        if (flag === 48) return done();
      }
    }

    sock.on("data", onData);
    sock.on("error", (e) => done(e));
    sock.on("end", () => done(new Error("Socket ended before final '0' packet")));
  });
}

async function absRoundtrip(payload, timeoutMs = DEFAULT_TIMEOUT_MS) {
  const sock = new net.Socket();
  await new Promise((res, rej) => sock.connect(ABS_PORT, ABS_HOST, res).once("error", rej));
  try {
    await absSend(sock, payload || Buffer.alloc(0));
    const replyConcat = await absRecv(sock, timeoutMs);
    sock.end();
    return replyConcat;
  } catch (e) {
    try { sock.destroy(); } catch {}
    throw e;
  }
}

async function withRetry(fn, tries = RETRIES, delayMs = RETRY_DELAY_MS) {
  let lastErr;
  for (let i = 0; i < tries; i++) {
    try { return await fn(); }
    catch (e) { lastErr = e; if (i + 1 < tries) await new Promise(r => setTimeout(r, delayMs)); }
  }
  throw lastErr;
}

function encryptPasswordLikeMFC(plain) {
  const sec = new Date().getUTCSeconds();
  const key = Number(String(sec)[0] || "0");
  let out = "";
  const s = (plain ?? "").toString();
  for (let i = 0; i < s.length; i++) {
    const ch = s[i];
    const d = (ch >= "0" && ch <= "9") ? (ch.charCodeAt(0) - 48) : 0;
    out += String((d + key) % 10);
  }
  return { enc: out + String(key), key, utcSeconds: sec };
}

function packSndHeader({ nTxnCd, nOpCd = 0, nNumRecsSent = 0, nNumRecsRqrd = 0, nTxnId = 0, cBtMake = 0 }) {
  const b = Buffer.alloc(24, 0);
  let o = 0;
  b.writeInt32LE(nTxnCd, o); o += 4;
  b.writeInt32LE(nOpCd, o); o += 4;
  b.writeInt32LE(nNumRecsSent, o); o += 4;
  b.writeInt32LE(nNumRecsRqrd, o); o += 4;
  b.writeInt32LE(nTxnId, o); o += 4;
  b.writeUInt8(cBtMake & 0xff, o);
  return b;
}

function parseRcvHeaderFlexible(buf) {
  if (buf.length < 18) throw new Error(`Reply too short for RcvHeader: ${buf.length} bytes`);
  function readAs(len) {
    let o = 0;
    const nTxnCd = buf.readInt32LE(o); o += 4;
    const nRetCd = buf.readInt32LE(o); o += 4;
    const nNumRecs = buf.readInt32LE(o); o += 4;
    const nTxnId = buf.readInt32LE(o); o += 4;
    const cBtMake = buf.readUInt8(o);
    return { nTxnCd, nRetCd, nNumRecs, nTxnId, cBtMake, size: len };
  }
  const h18 = readAs(18);
  const ok18 = (h18.nTxnCd >= 50 && h18.nTxnCd < 10000) && (h18.nRetCd >= 0 && h18.nRetCd < 10000) && (h18.nNumRecs >= 0 && h18.nNumRecs < 100);
  let h24 = null, ok24 = false;
  if (buf.length >= 24) {
    h24 = readAs(24);
    ok24 = (h24.nTxnCd >= 50 && h24.nTxnCd < 10000) && (h24.nRetCd >= 0 && h24.nRetCd < 10000) && (h24.nNumRecs >= 0 && h24.nNumRecs < 100);
  }
  if (ok18 && !ok24) return h18;
  if (!ok18 && ok24) return h24;
  if (ok18 && ok24) return h18;
  return h18;
}

function buildRcvHeader18({ nTxnCd, nRetCd, nNumRecs = 0, nTxnId = 0, cBtMake = 0 }) {
  const b = Buffer.alloc(18, 0);
  let o = 0;
  b.writeInt32LE(nTxnCd, o); o += 4;
  b.writeInt32LE(nRetCd, o); o += 4;
  b.writeInt32LE(nNumRecs, o); o += 4;
  b.writeInt32LE(nTxnId, o); o += 4;
  b.writeUInt8(cBtMake & 0xff, o);
  return b;
}

function alignToAsciiYear(reply, off) {
  const tryOffsets = [0, 2, 4, -4, 8, 12];
  for (const d of tryOffsets) {
    const o = off + d;
    if (o >= 0 && o + 1 < reply.length) {
      const b0 = reply[o], b1 = reply[o + 1];
      if (b0 === 0x32 && b1 === 0x30) return o;
      if (reply[o] === 0x2f && o >= 4 && reply[o - 4] === 0x32 && reply[o - 3] === 0x30) return o - 4;
    }
  }
  return off;
}

function packSndLog({ usrId = "", opCard, passwd, btId }) {
  const b = Buffer.alloc(38, 0);
  let o = 0;
  o = writeFixedAscii(b, o, usrId, 5);
  o = writeFixedAscii(b, o, opCard, 17);
  o = writeFixedAscii(b, o, passwd, 11);
  o = writeFixedAscii(b, o, btId, 5);
  return b;
}

function parseRcvLog(buf, offset = 0) {
  let o = offset;
  const t1 = readFixedAscii(buf, o, 20); const cDateTime = t1.value; o = t1.next;
  const t2 = readFixedAscii(buf, o, 31); const cUsrNm = t2.value; o = t2.next;
  const t3 = readFixedAscii(buf, o, 5); const cUsrId = t3.value; o = t3.next;
  const t4 = readFixedAscii(buf, o, 31); const cSupNm = t4.value; o = t4.next;
  const t5 = readFixedAscii(buf, o, 5); const cSupId = t5.value; o = t5.next;
  const t6 = readFixedAscii(buf, o, 5); const cUsrTyp = t6.value; o = t6.next;

  function rf() { const v = buf.readFloatLE(o); o += 4; return v; }
  function ri() { const v = buf.readInt32LE(o); o += 4; return v; }

  const fOpenBal = rf();
  const fTktSalesByVoucher = rf();
  const fTktSalesByCash = rf();
  const fTktSalesByMemCard = rf();
  const nTktSalesByVoucherCount = ri();
  const nTktSalesByCashCount = ri();
  const nTktSalesByMemCardCount = ri();
  const fPayoutByVoucher = rf();
  const fPayoutByCash = rf();
  const fPayoutByMemCard = rf();
  const nPayoutByVoucherCount = ri();
  const nPayoutByCashCount = ri();
  const nPayoutByMemCardCount = ri();
  const fCancelByVoucher = rf();
  const fCancelByCash = rf();
  const fCancelByMemCard = rf();
  const nCancelByVoucherCount = ri();
  const nCancelByCashCount = ri();
  const nCancelByMemCardCount = ri();
  const fDeposit = rf();
  const fWithdrawAmt = rf();
  const fVoucherSales = rf();
  const fVoucherEncash = rf();
  const fCloseBal = rf();
  const fSaleTarget = rf();

  return {
    cDateTime, cUsrNm, cUsrId, cSupNm, cSupId, cUsrTyp,
    fOpenBal, fTktSalesByVoucher, fTktSalesByCash, fTktSalesByMemCard,
    nTktSalesByVoucherCount, nTktSalesByCashCount, nTktSalesByMemCardCount,
    fPayoutByVoucher, fPayoutByCash, fPayoutByMemCard,
    nPayoutByVoucherCount, nPayoutByCashCount, nPayoutByMemCardCount,
    fCancelByVoucher, fCancelByCash, fCancelByMemCard,
    nCancelByVoucherCount, nCancelByCashCount, nCancelByMemCardCount,
    fDeposit, fWithdrawAmt, fVoucherSales, fVoucherEncash,
    fCloseBal, fSaleTarget,
    size: o - offset
  };
}

function parseRcvBtiMst(buf, offset) {
  let o = offset;
  const a1 = readFixedAscii(buf, o, 5); const cBtId = a1.value; o = a1.next;
  const a2 = readFixedAscii(buf, o, 31); const cBtName = a2.value; o = a2.next;
  const a3 = readFixedAscii(buf, o, 5); const cEnclCd = a3.value; o = a3.next;
  const a4 = readFixedAscii(buf, o, 4); const cGrpCd = a4.value; o = a4.next;
  const cBtMode = String.fromCharCode(buf[o]); o += 1;
  const a5 = readFixedAscii(buf, o, 4); const cMoneyTyp = a5.value; o = a5.next;
  o = (o + 3) & ~3;
  const fMinSaleBet = buf.readFloatLE(o); o += 4;
  const fMaxSaleBet = buf.readFloatLE(o); o += 4;
  const fPayMaxAmt = buf.readFloatLE(o); o += 4;
  return { cBtId, cBtName, cEnclCd, cGrpCd, cBtMode, cMoneyTyp, fMinSaleBet, fMaxSaleBet, fPayMaxAmt, size: o - offset };
}

function parseRcvBtiDtl(buf, offset) {
  let o = offset;
  const cDtlTyp = String.fromCharCode(buf[o]); o += 1;
  if (remaining(buf, o) < 4) {
    const avail = Math.max(0, remaining(buf, o));
    const aRem = readFixedAscii(buf, o, avail);
    const cPoolOrVenue = aRem.value;
    o = aRem.next;
    const cDtlSts = o < buf.length ? String.fromCharCode(buf[o]) : "";
    if (o < buf.length) o += 1;
    return { cDtlTyp, cPoolOrVenue, cDtlSts, size: o - offset };
  }
  const a3 = readFixedAscii(buf, o, 3);
  const cPoolOrVenue3 = a3.value;
  const after3 = a3.next;
  const statusCandidate = buf[after3];
  const isPrintable = (statusCandidate >= 0x20 && statusCandidate <= 0x7E);
  if (isPrintable) {
    o = after3;
    const cDtlSts = String.fromCharCode(buf[o]); o += 1;
    return { cDtlTyp, cPoolOrVenue: cPoolOrVenue3, cDtlSts, size: o - offset };
  }
  const a4 = readFixedAscii(buf, o, 4);
  const cPoolOrVenue4 = a4.value;
  o = a4.next;
  const cDtlSts = o < buf.length ? String.fromCharCode(buf[o]) : "";
  if (o < buf.length) o += 1;
  return { cDtlTyp, cPoolOrVenue: cPoolOrVenue4, cDtlSts, size: o - offset };
}

function parseRcvRpi1(buf, offset) {
  let o = offset;
  const nRaceDt = buf.readInt32LE(o); o += 4;
  const cVenueNum = buf.readUInt8(o); o += 1;
  const cVenueSts = String.fromCharCode(buf[o]); o += 1;
  const aR = readFixedAscii(buf, o, 15); const cRaces = aR.value; o = aR.next;
  const aAd = readFixedAscii(buf, o, 41); const cAdvertisement = aAd.value; o = aAd.next;
  return { nRaceDt, cVenueNum, cVenueSts, cRaces, cAdvertisement, size: o - offset };
}

function parseRcvRpi2(buf, offset) {
  let o = offset;
  const nRaceDt = buf.readInt32LE(o); o += 4;
  const cVenueNum = buf.readUInt8(o); o += 1;
  const cRaceNum = buf.readUInt8(o); o += 1;
  const aH = readFixedAscii(buf, o, 25); const cHorses = aH.value; o = aH.next;
  const nRaceStartTm = buf.readInt32LE(o); o += 4;
  return { nRaceDt, cVenueNum, cRaceNum, cHorses, nRaceStartTm, size: o - offset };
}

function parseRcvRpi3(buf, offset) {
  let o = offset;
  const nRaceDt = buf.readInt32LE(o); o += 4;
  const cVenueNum = buf.readUInt8(o); o += 1;
  const cRaceNum = buf.readUInt8(o); o += 1;
  const aP = readFixedAscii(buf, o, 9); const cPools = aP.value; o = aP.next;
  return { nRaceDt, cVenueNum, cRaceNum, cPools, size: o - offset };
}

function parseRcvRpi4(buf, offset) {
  let o = offset;
  const nRaceDt = buf.readInt32LE(o); o += 4;
  const cVenueNum = buf.readUInt8(o); o += 1;
  const cRaceNum = buf.subarray(o, o + 3).toString("ascii").replace(/\0/g, ""); o += 3;
  const aSel = readFixedAscii(buf, o, 11); const cSelectRaceNum = aSel.value; o = aSel.next;
  const cPoolSts = String.fromCharCode(buf[o]); o += 1;
  return { nRaceDt, cVenueNum, cRaceNum, cSelectRaceNum, cPoolSts, size: o - offset };
}

function parseRcvPvm(buf, offset) {
  let o = offset;
  const a1 = readFixedAscii(buf, o, 4); const cRaceVenue = a1.value; o = a1.next;
  const a2 = readFixedAscii(buf, o, 4); const cPoolId = a2.value; o = a2.next;
  const fUnitPrice = buf.readFloatLE(o); o += 4;
  const fTaxRate = buf.readFloatLE(o); o += 4;
  const fDeductRate = buf.readFloatLE(o); o += 4;
  const a3 = readFixedAscii(buf, o, 31); const cRemarks = a3.value; o = a3.next;
  return { cRaceVenue, cPoolId, fUnitPrice, fTaxRate, fDeductRate, cRemarks, size: o - offset };
}

app.get("/", (_req, res) => res.send("ABS bridge is up"));

app.get("/health", (_req, res) => {
  const s = new net.Socket();
  s.setTimeout(1500);
  s.connect(ABS_PORT, ABS_HOST, () => { s.destroy(); res.json({ ok: true, target: `${ABS_HOST}:${ABS_PORT}` }); });
  s.on("timeout", () => { s.destroy(); res.status(504).json({ ok: false, error: "TCP timeout" }); });
  s.on("error", (e) => { s.destroy(); res.status(502).json({ ok: false, error: String(e) }); });
});

app.post("/abs/poll", async (req, res) => {
  try {
    const body = await readJsonBody(req);
    const btMake = (typeof body.btMake === "string")
      ? body.btMake.charCodeAt(0)
      : (Number.isFinite(body.btMake) ? (body.btMake | 0) : 0x00);

    const header = packSndHeader({ nTxnCd: ABS_POLL, nOpCd: 0, nNumRecsSent: 0, nNumRecsRqrd: 0, nTxnId: 0, cBtMake: btMake });

    const reply = await withRetry(() => absRoundtrip(header, DEFAULT_TIMEOUT_MS), RETRIES, RETRY_DELAY_MS);
    const hdr = parseRcvHeaderFlexible(reply.subarray(0, Math.min(reply.length, 24)));

    res.json({
      ok: true,
      target: `${ABS_HOST}:${ABS_PORT}`,
      sentHeaderHex: header.toString("hex"),
      replyBytes: reply.length,
      replyHexFirst64: reply.subarray(0, 64).toString("hex"),
      parsedRcvHeaderRaw: hdr,
      normalizedRcvHeader: { ...hdr, size: 18 },
      normalizedHeaderHex: buildRcvHeader18(hdr).toString("hex"),
      success: hdr.nRetCd === SUCCESS
    });
  } catch (e) {
    res.status(502).json({ ok: false, error: String(e) });
  }
});

app.post("/login", async (req, res) => {
  try {
    const body = await readJsonBody(req);
    const opCard = (body.opCard ?? "").toString();
    const btId = (body.btId ?? "").toString();
    const usrId = (body.usrId ?? "").toString();
    const plain = (body.password ?? "");
    const givenEnc = (body.passwordEnc ?? "");

    if (!opCard || !btId || (!plain && !givenEnc)) {
      return res.status(400).json({ ok: false, error: "Missing opCard, btId, and either password or passwordEnc" });
    }

    let encInfo = null;
    let passwd = givenEnc ? String(givenEnc) : (encInfo = encryptPasswordLikeMFC(String(plain))).enc;

    const btMake = (typeof body.btMake === "string")
      ? body.btMake.charCodeAt(0)
      : (Number.isFinite(body.btMake) ? (body.btMake | 0) : 0x00);

    const sndHeader = packSndHeader({ nTxnCd: LOG, nOpCd: LOGBT, nNumRecsSent: 1, nNumRecsRqrd: 1, nTxnId: 0, cBtMake: btMake });
    const sndLog = packSndLog({ usrId, opCard, passwd, btId });
    const sendBuf = Buffer.concat([sndHeader, sndLog]);

    const reply = await withRetry(() => absRoundtrip(sendBuf, DEFAULT_TIMEOUT_MS), RETRIES, RETRY_DELAY_MS);

    const rcvHeader = parseRcvHeaderFlexible(reply.subarray(0, Math.min(reply.length, 24)));

    const json = {
      ok: true,
      target: `${ABS_HOST}:${ABS_PORT}`,
      sentHeaderHex: sndHeader.toString("hex"),
      sentBodyHex: sndLog.toString("hex"),
      replyBytes: reply.length,
      replyHexFirst64: reply.subarray(0, 64).toString("hex"),
      rcvHeaderRaw: rcvHeader,
      success: rcvHeader.nRetCd === SUCCESS
    };

    if (!givenEnc && encInfo) {
      json.encryption = { used: true, utcSeconds: encInfo.utcSeconds, key: encInfo.key, encPasswd: passwd };
    } else if (givenEnc) {
      json.encryption = { used: false, providedPasswordEnc: true };
    }

    let bodyOffset = rcvHeader.size;
    bodyOffset = adjustForOptionalOp(reply, bodyOffset).offset;
    bodyOffset = alignToAsciiYear(reply, bodyOffset);

    json.offsetProbe = {
      bodyOffset,
      around: reply.subarray(Math.max(0, bodyOffset - 8), Math.min(reply.length, bodyOffset + 48)).toString("ascii")
    };

    if (json.success && reply.length >= bodyOffset + 20) {
      try { json.log = parseRcvLog(reply, bodyOffset); } catch (e) { json.parseLogError = String(e); }
    }

    res.json(json);
  } catch (e) {
    res.status(502).json({ ok: false, error: String(e) });
  }
});

app.post("/download/btinfo", async (req, res) => {
  try {
    const body = await readJsonBody(req);
    const opCard = (body.opCard ?? "").toString();
    const btId = (body.btId ?? "").toString();
    const usrId = (body.usrId ?? "").toString();
    const plain = (body.password ?? "");
    const encPass = (body.passwordEnc ?? "");
    if (!opCard || !btId || (!plain && !encPass)) {
      return res.status(400).json({ ok: false, error: "Missing opCard, btId, and either password or passwordEnc" });
    }
    const passwd = encPass ? String(encPass) : encryptPasswordLikeMFC(String(plain)).enc;

    const sndHeader = packSndHeader({ nTxnCd: LOG, nOpCd: BTI, nNumRecsSent: 1, nNumRecsRqrd: 1, nTxnId: 0, cBtMake: 0 });
    const sndLog = packSndLog({ usrId, opCard, passwd, btId });
    const sendBuf = Buffer.concat([sndHeader, sndLog]);

    const reply = await withRetry(() => absRoundtrip(sendBuf, DEFAULT_TIMEOUT_MS), RETRIES, RETRY_DELAY_MS);

    const result = { ok: true, replyBytes: reply.length, replyHexFirst64: reply.subarray(0, 64).toString("hex") };

    let offset = 0;
    if (remaining(reply, offset) < 18) return res.json({ ok: false, error: "truncated: no header" });

    const hdr = parseRcvHeaderFlexible(reply.subarray(offset, Math.min(reply.length, offset + 24)));
    result.primaryHeader = hdr;

    const hdrLenAligned = (hdr.size + 3) & ~3;
    if (!safeAdvanceOrBreak(reply, 0, hdrLenAligned, result)) {
      result.error = "truncated: incomplete header (after alignment)";
      return res.json(result);
    }
    offset = hdrLenAligned;

    if (hdr.nRetCd !== SUCCESS) {
      result.error = `server returned nRetCd=${hdr.nRetCd}`;
      return res.json(result);
    }

    if (!safeAdvanceOrBreak(reply, offset, 5 + 31 + 5 + 4 + 1 + 4 + 4 + 4 + 4, result)) {
      result.error = "truncated before BTI master";
      return res.json(result);
    }
    const btiMst = parseRcvBtiMst(reply, offset);
    offset += btiMst.size;
    result.btiMst = btiMst;

    const details = [];
    let readCount = 0;
    while (readCount < hdr.nNumRecs) {
      if (looksLikeHeaderAt(reply, offset)) break;
      if (!safeAdvanceOrBreak(reply, offset, 1 + 3 + 1, result)) break;
      const dt = parseRcvBtiDtl(reply, offset);
      offset += dt.size;
      details.push(dt);
      readCount++;
    }
    result.btiDetails = details;
    result.btiReadCount = readCount;
    result.parsedBytes = offset;

    res.json(result);
  } catch (e) {
    res.status(502).json({ ok: false, error: String(e), stack: e.stack });
  }
});

app.post("/download/rpinfo", async (req, res) => {
  try {
    const body = await readJsonBody(req);
    const debug = String((req.query.debug ?? "")).toLowerCase() === "1";
    const opCard = (body.opCard ?? "").toString();
    const btId = (body.btId ?? "").toString();
    const usrId = (body.usrId ?? "").toString();
    const plain = (body.password ?? "");
    const encPass = (body.passwordEnc ?? "");

    if (!opCard || !btId || (!plain && !encPass)) {
      return res.status(400).json({ ok: false, error: "Missing opCard, btId, and either password or passwordEnc" });
    }

    const passwd = encPass ? String(encPass) : encryptPasswordLikeMFC(String(plain)).enc;
    const btAdvSalesFlg = body.btAdvSalesFlg || "N";
    const nBtAdvSaleEnb = btAdvSalesFlg === "A" ? 1 : 0;

    const sndHeader = packSndHeader({ nTxnCd: LOG, nOpCd: RPI, nNumRecsSent: 1, nNumRecsRqrd: nBtAdvSaleEnb, nTxnId: 0, cBtMake: 0 });
    const sndLog = packSndLog({ usrId, opCard, passwd, btId });
    const sendBuf = Buffer.concat([sndHeader, sndLog]);

    const reply = await withRetry(() => absRoundtrip(sendBuf, DEFAULT_TIMEOUT_MS), RETRIES, RETRY_DELAY_MS);

    const result = { ok: true, replyBytes: reply.length, replyHexFirst64: reply.subarray(0, 64).toString("hex") };
    let offset = 0;

    if (remaining(reply, offset) < 18) return res.json({ ok: false, error: "truncated: no top header" });
    const topHdr = parseRcvHeaderFlexible(reply.subarray(offset, Math.min(reply.length, offset + 24)));
    offset += topHdr.size;
    result.topHeader = topHdr;

    if (topHdr.nRetCd !== SUCCESS) {
      result.error = `server returned nRetCd=${topHdr.nRetCd}`;
      return res.json(result);
    }

    if (debug) result.debug_afterTopHdr = { offset, hex: hexSlice(reply, offset, 128) };

    function parseSection(minRecBytes, recParser, outArrName, outHeaderName, expected_nTxnCd) {
      const items = [];
      let read = 0;
      let hdr = null;

      if (remaining(reply, offset) < 18) {
        result[outArrName] = items;
        result[outHeaderName] = null;
        result[outArrName.replace(/s?$/, "ReadCount")] = read;
        if (debug) result[`debug_${outArrName}_no_data`] = `No data for ${outArrName}, offset=${offset}, remaining=${remaining(reply, offset)}`;
        return items;
      }

      // Try parsing header
      offset = alignToPossibleHeader(reply, offset, expected_nTxnCd);
      if (looksLikeHeaderAt(reply, offset, expected_nTxnCd)) {
        hdr = parseRcvHeaderFlexible(reply.subarray(offset, Math.min(reply.length, offset + 24)));
        offset += hdr.size;
        const adj = adjustForOptionalOp(reply, offset);
        offset = adj.offset;

        if (debug) result[`debug_${outArrName}_header`] = { offset, hdr, hex: hexSlice(reply, offset - hdr.size, 64), expected_nTxnCd };

        while (read < hdr.nNumRecs && remaining(reply, offset) >= minRecBytes) {
          try {
            const rec = recParser(reply, offset);
            if (rec && rec.nRaceDt >= 20000101 && rec.nRaceDt <= 21001231 && rec.cVenueNum >= 1 && rec.cVenueNum <= MAX_VENUES) {
              items.push(rec);
              offset += rec.size;
              read++;
            } else {
              offset += 1;
              if (debug) result[`debug_${outArrName}_invalid`] = `Invalid record at offset ${offset}: ${JSON.stringify(rec)}`;
            }
          } catch (e) {
            if (debug) result[`debug_${outArrName}_error`] = `Error at offset ${offset}: ${e.message}`;
            offset += 1;
            break;
          }
        }
      } else {
        // Fallback: try parsing data directly if no valid header
        if (remaining(reply, offset) >= minRecBytes) {
          try {
            const rec = recParser(reply, offset);
            if (rec && rec.nRaceDt >= 20000101 && rec.nRaceDt <= 21001231 && rec.cVenueNum >= 1 && rec.cVenueNum <= MAX_VENUES) {
              items.push(rec);
              offset += rec.size;
              read++;
              if (debug) result[`debug_${outArrName}_fallback`] = `Parsed ${outArrName} data without valid header at offset ${offset - rec.size}`;
            } else {
              if (debug) result[`debug_${outArrName}_fallback_invalid`] = `Fallback invalid record at offset ${offset}: ${JSON.stringify(rec)}`;
            }
          } catch (e) {
            if (debug) result[`debug_${outArrName}_fallback_error`] = `Fallback parse error at offset ${offset}: ${e.message}`;
          }
        }
        if (debug) result[`debug_${outArrName}_noheader`] = `No valid header for ${outArrName} at offset ${offset}, expected nTxnCd=${expected_nTxnCd}, hex=${hexSlice(reply, offset, 64)}`;
      }

      result[outHeaderName] = hdr;
      result[outArrName] = items;
      result[outArrName.replace(/s?$/, "ReadCount")] = read;
      if (debug) result[`debug_${outArrName}_after`] = { offset, hex: hexSlice(reply, offset, 128) };
      return items;
    }

    // Parse sections with expected nTxnCd
    const sections = [
      { minRecBytes: 4 + 1 + 1 + 15 + 41, parser: parseRcvRpi1, arrName: "rpi1", headerName: "rpi1Header", nTxnCd: 101 },
      { minRecBytes: 4 + 1 + 1 + 25 + 4, parser: parseRcvRpi2, arrName: "rpi2", headerName: "rpi2Header", nTxnCd: 102 },
      { minRecBytes: 4 + 1 + 1 + 9, parser: parseRcvRpi3, arrName: "rpi3", headerName: "rpi3Header", nTxnCd: 103 },
      { minRecBytes: 4 + 1 + 3 + 11 + 1, parser: parseRcvRpi4, arrName: "rpi4", headerName: "rpi4Header", nTxnCd: 104 },
      { minRecBytes: 4 + 4 + 4 + 4 + 4 + 31, parser: parseRcvPvm, arrName: "pvms", headerName: "pvmHeader", nTxnCd: 105 }
    ];

    for (const section of sections) {
      parseSection(section.minRecBytes, section.parser, section.arrName, section.headerName, section.nTxnCd);
    }

    result.parsedBytes = offset;

    // Build raceCard
    const raceCard = [];
    for (const v of result.rpi1 || []) {
      const raceDate = getDateStr(v.nRaceDt);
      const venueId = getVenueIdStr(v.cVenueNum);
      const venueSts = v.cVenueSts;

      for (let nRace = 0; nRace < MAX_RACES; nRace++) {
        if (v.cRaces[nRace] === "0" || !v.cRaces[nRace]) continue;
        const raceNum = (nRace + 1).toString().padStart(2, "0");
        raceCard.push({
          RACE_DATE: raceDate,
          RACE_VENUE_ID: venueId,
          RACE_NO: raceNum,
          STOPBET_STATUS: v.cRaces[nRace] === "C" ? "S" : v.cRaces[nRace],
          RACE_STATUS: v.cRaces[nRace] === "C" ? "C" : "V",
          VENUE_STATUS: venueSts,
          START_TIME: "",
          ADVT: v.cAdvertisement,
          horses: [],
          pools: []
        });
      }
    }

    for (const r of result.rpi2 || []) {
      const raceDate = getDateStr(r.nRaceDt);
      const venueId = getVenueIdStr(r.cVenueNum);
      const raceNum = r.cRaceNum.toString().padStart(2, "0");

      for (let nHorse = 0; nHorse < MAX_HORSES; nHorse++) {
        if (r.cHorses[nHorse] === "0" || !r.cHorses[nHorse]) continue;
        const horseNum = (nHorse + 1).toString().padStart(2, "0");
        const entry = raceCard.find(e => e.RACE_DATE === raceDate && e.RACE_VENUE_ID === venueId && e.RACE_NO === raceNum);
        if (entry) {
          entry.horses.push({
            RACE_HORSE_NO: horseNum,
            HORSE_STATUS: r.cHorses[nHorse],
            REFUND_FILE_STATUS: ""
          });
          if (!entry.START_TIME) {
            entry.START_TIME = getTimeStr(r.nRaceStartTm);
          }
        }
      }
    }

    for (const p of result.rpi3 || []) {
      const raceDate = getDateStr(p.nRaceDt);
      const venueId = getVenueIdStr(p.cVenueNum);
      const raceNum = p.cRaceNum.toString().padStart(2, "0");

      for (let nPoolId = 0; nPoolId < MAX_POOLS; nPoolId++) {
        if (p.cPools[nPoolId] === "0" || !p.cPools[nPoolId]) continue;
        const entry = raceCard.find(e => e.RACE_DATE === raceDate && e.RACE_VENUE_ID === venueId && e.RACE_NO === raceNum);
        if (entry) {
          entry.pools.push({
            POOL_ID: getPoolIdStr(nPoolId + 1),
            POOL_STATUS: p.cPools[nPoolId],
            BETTING_CENTRE_ID: "",
            SELECT_RACE_NO: ""
          });
        }
      }
    }

    for (const s of result.rpi4 || []) {
      const raceDate = getDateStr(s.nRaceDt);
      const venueId = getVenueIdStr(s.cVenueNum);
      const raceNum = s.cRaceNum;
      const venueSts = raceCard.find(e => e.RACE_DATE === raceDate && e.RACE_VENUE_ID === venueId)?.VENUE_STATUS || "V";

      let entry = raceCard.find(e => e.RACE_DATE === raceDate && e.RACE_VENUE_ID === venueId && e.RACE_NO === raceNum);
      if (!entry) {
        entry = {
          RACE_DATE: raceDate,
          RACE_VENUE_ID: venueId,
          RACE_NO: raceNum,
          STOPBET_STATUS: "",
          RACE_STATUS: s.cPoolSts,
          VENUE_STATUS: venueSts,
          START_TIME: "",
          ADVT: "",
          horses: [],
          pools: []
        };
        raceCard.push(entry);
      }

      entry.pools.push({
        POOL_ID: getMultiLegPoolIdStr(s.cRaceNum),
        POOL_STATUS: s.cPoolSts,
        BETTING_CENTRE_ID: "",
        SELECT_RACE_NO: s.cSelectRaceNum
      });
    }

    for (const p of result.rpi3 || []) {
      if (!p.cPools.includes("TBP") && !p.cPools.includes("MJP") && !p.cPools.includes("JPP")) continue;
      const raceDate = getDateStr(p.nRaceDt);
      const venueId = getVenueIdStr(p.cVenueNum);
      const raceNum = p.cRaceNum.toString().padStart(2, "0");

      for (const s of result.rpi4 || []) {
        if (s.cSelectRaceNum && s.nRaceDt === p.nRaceDt && s.cVenueNum === p.cVenueNum) {
          const selectRaceNum = s.cSelectRaceNum.slice(0, 2);
          const selectEntry = raceCard.find(e => e.RACE_DATE === raceDate && e.RACE_VENUE_ID === venueId && e.RACE_NO === selectRaceNum);
          const targetEntry = raceCard.find(e => e.RACE_DATE === raceDate && e.RACE_VENUE_ID === venueId && e.RACE_NO === raceNum);
          if (selectEntry && targetEntry) {
            targetEntry.STOPBET_STATUS = selectEntry.STOPBET_STATUS;
          }
        }
      }
    }

    const pvmData = (result.pvms || []).map(p => ({
      RACE_VENUE: p.cRaceVenue,
      POOL_ID: p.cPoolId,
      UNIT_PRICE: p.fUnitPrice,
      TAX_RATE: p.fTaxRate,
      DEDUCT_RATE: p.fDeductRate,
      REMARKS: p.cRemarks
    }));

    result.raceCard = raceCard;
    result.pvm = pvmData;

    res.json(result);
  } catch (e) {
    res.status(502).json({ ok: false, error: String(e), stack: e.stack });
  }
});

const HTTP_PORT = Number(process.env.HTTP_BRIDGE_PORT || 8080);
app.listen(HTTP_PORT, () => {
  console.log(`ABS HTTP bridge listening on :${HTTP_PORT}`);
  console.log(`Target ABS server: ${ABS_HOST}:${ABS_PORT}`);
});