import crypto from 'node:crypto';
import fs from 'node:fs';
import http from 'node:http';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const SCRIPT_DIR = path.dirname(fileURLToPath(import.meta.url));
const PROJECT_ROOT = path.resolve(SCRIPT_DIR, '..', '..');
const TOKENS_DIR = path.join(PROJECT_ROOT, 'tokens');

function readJsonFile(filePath) {
  try {
    const raw = fs.readFileSync(filePath, 'utf8');
    return JSON.parse(raw);
  } catch {
    return undefined;
  }
}

function getIsoNow() {
  return new Date().toISOString();
}

function base64Url(buf) {
  return Buffer.from(buf)
    .toString('base64')
    .replace(/=/g, '')
    .replace(/\+/g, '-')
    .replace(/\//g, '_');
}

function sha256Hex(text) {
  return crypto.createHash('sha256').update(text, 'utf8').digest('hex');
}

function generateToken() {
  return `alg_${base64Url(crypto.randomBytes(32))}`;
}

function getHeader(req, name) {
  const v = req.headers[String(name).toLowerCase()];
  return Array.isArray(v) ? v[0] : v;
}

function readBearerToken(req) {
  const auth = getHeader(req, 'authorization');
  if (auth && typeof auth === 'string') {
    const m = auth.match(/^Bearer\s+(.+)$/i);
    if (m && m[1]) return m[1].trim();
  }
  const apiKey = getHeader(req, 'x-api-key');
  if (apiKey && typeof apiKey === 'string' && apiKey.trim()) return apiKey.trim();
  return undefined;
}

function withCors(res, corsOrigin) {
  res.setHeader('access-control-allow-origin', corsOrigin);
  res.setHeader('access-control-allow-methods', 'GET,POST,OPTIONS');
  res.setHeader(
    'access-control-allow-headers',
    'content-type, authorization, x-api-key, x-admin-secret'
  );
}

function sendJson(res, status, body, corsOrigin) {
  withCors(res, corsOrigin);
  res.statusCode = status;
  res.setHeader('content-type', 'application/json; charset=utf-8');
  res.end(JSON.stringify(body));
}

async function readBodyJson(req, { maxBytes }) {
  const chunks = [];
  let total = 0;
  for await (const chunk of req) {
    total += chunk.length;
    if (total > maxBytes) throw new Error('payload_too_large');
    chunks.push(chunk);
  }
  const text = Buffer.concat(chunks).toString('utf8');
  if (!text.trim()) return {};
  try {
    return JSON.parse(text);
  } catch {
    throw new Error('invalid_json');
  }
}

function normalizeGraphqlName(value, fallback, label) {
  const v = String(value || fallback || '')
    .trim()
    .toLowerCase();
  if (!v) return String(fallback || '');
  if (!/^[a-z][a-z0-9_]*$/.test(v)) throw new Error(`Invalid ${label}: ${value}`);
  return v;
}

function resolveConfig() {
  const hasuraTokens = readJsonFile(path.join(TOKENS_DIR, 'hasura.json')) || {};
  const apiTokens = readJsonFile(path.join(TOKENS_DIR, 'api.json')) || {};

  const portRaw = process.env.PORT || process.env.API_PORT || apiTokens.port || '8787';
  const port = Number.parseInt(String(portRaw), 10);
  if (!Number.isInteger(port) || port <= 0) throw new Error(`Invalid PORT: ${portRaw}`);

  const hasuraUrl =
    process.env.HASURA_GRAPHQL_URL ||
    hasuraTokens.graphqlUrl ||
    hasuraTokens.apiUrl ||
    'http://localhost:8080/v1/graphql';

  const hasuraAdminSecret =
    process.env.HASURA_ADMIN_SECRET || hasuraTokens.adminSecret || hasuraTokens.hasuraAdminSecret;

  const apiAdminSecret = process.env.API_ADMIN_SECRET || apiTokens.adminSecret;

  const corsOrigin = process.env.CORS_ORIGIN || apiTokens.corsOrigin || '*';

  const appVersion = String(process.env.APP_VERSION || 'v1').trim() || 'v1';
  const buildTimestamp = String(process.env.BUILD_TIMESTAMP || '').trim() || undefined;
  const startedAt = getIsoNow();

  const ticksTable = normalizeGraphqlName(process.env.TICKS_TABLE, 'drift_ticks', 'TICKS_TABLE');
  const candlesFunction = normalizeGraphqlName(
    process.env.CANDLES_FUNCTION,
    'get_drift_candles',
    'CANDLES_FUNCTION'
  );

  return {
    port,
    hasuraUrl,
    hasuraAdminSecret,
    apiAdminSecret,
    corsOrigin,
    appVersion,
    buildTimestamp,
    startedAt,
    ticksTable,
    candlesFunction,
  };
}

async function hasuraRequest(cfg, { admin }, query, variables) {
  const headers = { 'content-type': 'application/json' };
  if (admin) {
    if (!cfg.hasuraAdminSecret) throw new Error('Missing HASURA_ADMIN_SECRET (or tokens/hasura.json adminSecret)');
    headers['x-hasura-admin-secret'] = cfg.hasuraAdminSecret;
  }

  const res = await fetch(cfg.hasuraUrl, {
    method: 'POST',
    headers,
    body: JSON.stringify({ query, variables }),
  });

  const text = await res.text();
  if (!res.ok) throw new Error(`Hasura HTTP ${res.status}: ${text}`);

  let json;
  try {
    json = JSON.parse(text);
  } catch {
    throw new Error(`Hasura invalid JSON: ${text}`);
  }
  if (json.errors?.length) {
    throw new Error(json.errors.map((e) => e.message).join(' | '));
  }
  return json.data;
}

function normalizeScopes(value) {
  if (!value) return [];
  if (Array.isArray(value)) return value.map((v) => String(v)).filter(Boolean);
  if (typeof value === 'string') {
    return value
      .split(',')
      .map((s) => s.trim())
      .filter(Boolean);
  }
  return [];
}

async function requireValidToken(cfg, req, requiredScope) {
  const token = readBearerToken(req);
  if (!token) return { ok: false, status: 401, error: 'missing_token' };

  const hash = sha256Hex(token);
  const query = `
    query ValidToken($hash: String!) {
      api_tokens(where: {token_hash: {_eq: $hash}, revoked_at: {_is_null: true}}, limit: 1) {
        id
        name
        scopes
      }
    }
  `;

  let data;
  try {
    data = await hasuraRequest(cfg, { admin: true }, query, { hash });
  } catch (err) {
    return { ok: false, status: 500, error: String(err?.message || err) };
  }

  const row = data?.api_tokens?.[0];
  if (!row?.id) return { ok: false, status: 401, error: 'invalid_or_revoked_token' };
  const scopes = normalizeScopes(row.scopes);
  if (requiredScope && !scopes.includes(requiredScope)) {
    return { ok: false, status: 403, error: 'missing_scope' };
  }

  // best-effort touch
  const touch = `
    mutation TouchToken($id: uuid!, $ts: timestamptz!) {
      update_api_tokens_by_pk(pk_columns: {id: $id}, _set: {last_used_at: $ts}) { id }
    }
  `;
  hasuraRequest(cfg, { admin: true }, touch, { id: row.id, ts: new Date().toISOString() }).catch(() => {});

  return { ok: true, token: { id: row.id, name: row.name } };
}

function toNumericString(value, fieldName) {
  if (value == null) throw new Error(`invalid_${fieldName}`);
  if (typeof value === 'number') {
    if (!Number.isFinite(value)) throw new Error(`invalid_${fieldName}`);
    return String(value);
  }
  if (typeof value === 'string') {
    const s = value.trim();
    if (!s) throw new Error(`invalid_${fieldName}`);
    const n = Number(s);
    if (!Number.isFinite(n)) throw new Error(`invalid_${fieldName}`);
    return s;
  }
  // best-effort: allow bigint-like or BN-like objects
  if (typeof value?.toString === 'function') {
    const s = String(value.toString()).trim();
    if (!s) throw new Error(`invalid_${fieldName}`);
    const n = Number(s);
    if (!Number.isFinite(n)) throw new Error(`invalid_${fieldName}`);
    return s;
  }
  throw new Error(`invalid_${fieldName}`);
}

function normalizeTick(input, tokenInfo) {
  const ts = (input?.ts || input?.timestamp || getIsoNow())?.toString?.();
  const market_index = input?.market_index ?? input?.marketIndex;
  const symbol = input?.symbol;
  const oracle_price = input?.oracle_price ?? input?.oraclePrice ?? input?.price;
  const mark_price = input?.mark_price ?? input?.markPrice ?? input?.mark;
  const oracle_slot = input?.oracle_slot ?? input?.oracleSlot ?? input?.slot;
  const source = (input?.source || 'api')?.toString?.();
  const raw = input?.raw && typeof input.raw === 'object' ? input.raw : undefined;

  if (!ts || Number.isNaN(Date.parse(ts))) throw new Error('invalid_ts');
  if (!Number.isInteger(market_index)) throw new Error('invalid_market_index');
  if (typeof symbol !== 'string' || !symbol.trim()) throw new Error('invalid_symbol');
  const oracleStr = toNumericString(oracle_price, 'oracle_price');
  const markStr = mark_price == null ? undefined : toNumericString(mark_price, 'mark_price');

  const slotNum =
    oracle_slot == null ? undefined : Number.isFinite(Number(oracle_slot)) ? Number(oracle_slot) : undefined;

  const mergedRaw =
    raw || tokenInfo
      ? {
          ...(raw || {}),
          ingestedBy: tokenInfo ? { tokenId: tokenInfo.id, name: tokenInfo.name } : undefined,
        }
      : undefined;

  return {
    ts,
    market_index,
    symbol: symbol.trim(),
    // Postgres columns are NUMERIC; Hasura `numeric` scalar returns strings and expects string inputs.
    oracle_price: oracleStr,
    mark_price: markStr,
    oracle_slot: slotNum,
    source,
    raw: mergedRaw,
  };
}

async function insertTick(cfg, tick) {
  const table = cfg.ticksTable;
  const insertField = `insert_${table}_one`;
  const mutation = `
    mutation InsertTick($object: ${table}_insert_input!) {
      ${insertField}(object: $object) {
        id
      }
    }
  `;

  const data = await hasuraRequest(cfg, { admin: true }, mutation, { object: tick });
  return data?.[insertField]?.id;
}

async function createApiToken(cfg, name, scopes, meta) {
  const mutation = `
    mutation CreateToken($name: String!, $hash: String!, $scopes: [String!]!, $meta: jsonb) {
      insert_api_tokens_one(object: {name: $name, token_hash: $hash, scopes: $scopes, meta: $meta}) {
        id
        name
        created_at
      }
    }
  `;

  for (let attempt = 0; attempt < 5; attempt++) {
    const token = generateToken();
    const hash = sha256Hex(token);
    try {
      const data = await hasuraRequest(cfg, { admin: true }, mutation, { name, hash, scopes, meta });
      const row = data?.insert_api_tokens_one;
      if (!row?.id) throw new Error('token_insert_failed');
      return { token, row };
    } catch (err) {
      const msg = String(err?.message || err);
      const isUniqueConflict = msg.toLowerCase().includes('unique') || msg.toLowerCase().includes('constraint');
      if (!isUniqueConflict) throw err;
    }
  }
  throw new Error('token_generation_failed');
}

async function revokeApiToken(cfg, id) {
  const mutation = `
    mutation RevokeToken($id: uuid!, $ts: timestamptz!) {
      update_api_tokens_by_pk(pk_columns: {id: $id}, _set: {revoked_at: $ts}) {
        id
        revoked_at
      }
    }
  `;
  const data = await hasuraRequest(cfg, { admin: true }, mutation, { id, ts: new Date().toISOString() });
  return data?.update_api_tokens_by_pk?.id;
}

function clampInt(value, min, max) {
  const n = Number.parseInt(String(value), 10);
  if (!Number.isFinite(n) || !Number.isInteger(n)) return min;
  return Math.min(max, Math.max(min, n));
}

function clampNumber(value, min, max, fallback = min) {
  const n = typeof value === 'number' ? value : typeof value === 'string' ? Number(value) : NaN;
  if (!Number.isFinite(n)) return fallback;
  return Math.min(max, Math.max(min, n));
}

function parseNumeric(value) {
  if (value == null) return null;
  if (typeof value === 'number') return Number.isFinite(value) ? value : null;
  if (typeof value === 'string') {
    const t = value.trim();
    if (!t) return null;
    const n = Number(t);
    return Number.isFinite(n) ? n : null;
  }
  if (typeof value?.toString === 'function') {
    try {
      const n = Number(String(value.toString()).trim());
      return Number.isFinite(n) ? n : null;
    } catch {
      return null;
    }
  }
  return null;
}

function clampSeriesLimit(value, fallback) {
  const n = Number.parseInt(String(value ?? ''), 10);
  if (!Number.isFinite(n) || !Number.isInteger(n)) return fallback;
  return Math.min(10_000, Math.max(1, n));
}

function parseTimeframeToSeconds(tf) {
  const v = String(tf || '').trim().toLowerCase();
  if (!v) return 60;
  const m = v.match(/^(\d+)(s|m|h|d)$/);
  if (!m) throw new Error(`invalid_tf`);
  const num = Number.parseInt(m[1], 10);
  if (!Number.isInteger(num) || num <= 0) throw new Error(`invalid_tf`);
  const unit = m[2];
  const mult = unit === 's' ? 1 : unit === 'm' ? 60 : unit === 'h' ? 3600 : 86400;
  return num * mult;
}

function isTruthy(value) {
  if (typeof value === 'boolean') return value;
  const v = String(value ?? '').trim().toLowerCase();
  return v === '1' || v === 'true' || v === 'yes' || v === 'on';
}

const solPriceCache = { ts: 0, value: null };

async function readSolPriceUsd(cfg) {
  const now = Date.now();
  if (now - solPriceCache.ts < 5000) return solPriceCache.value;

  const table = cfg.ticksTable;
  const query = `
    query SolPrice($where: ${table}_bool_exp!) {
      ${table}(where: $where, order_by: {ts: desc}, limit: 1) {
        oracle_price
        mark_price
        ts
      }
    }
  `;

  try {
    const data = await hasuraRequest(cfg, { admin: true }, query, { where: { symbol: { _eq: 'SOL-PERP' } } });
    const row = (data?.[table] || [])[0];
    const price = parseNumeric(row?.oracle_price) ?? parseNumeric(row?.mark_price) ?? null;
    solPriceCache.ts = now;
    solPriceCache.value = price;
    return price;
  } catch {
    solPriceCache.ts = now;
    solPriceCache.value = null;
    return null;
  }
}

function mean(values) {
  if (!values.length) return 0;
  return values.reduce((a, b) => a + b, 0) / values.length;
}

function stddev(values) {
  if (!values.length) return 0;
  const m = mean(values);
  const v = values.reduce((acc, x) => acc + (x - m) * (x - m), 0) / values.length;
  return Math.sqrt(v);
}

function sma(values, period) {
  if (period <= 0) throw new Error('period must be > 0');
  const out = new Array(values.length).fill(null);
  let sum = 0;
  for (let i = 0; i < values.length; i++) {
    sum += values[i];
    if (i >= period) sum -= values[i - period];
    if (i >= period - 1) out[i] = sum / period;
  }
  return out;
}

function ema(values, period) {
  if (period <= 0) throw new Error('period must be > 0');
  const out = new Array(values.length).fill(null);
  const k = 2 / (period + 1);
  if (values.length < period) return out;
  const first = mean(values.slice(0, period));
  out[period - 1] = first;
  let prev = first;
  for (let i = period; i < values.length; i++) {
    const next = values[i] * k + prev * (1 - k);
    out[i] = next;
    prev = next;
  }
  return out;
}

function rsi(values, period) {
  if (period <= 0) throw new Error('period must be > 0');
  const out = new Array(values.length).fill(null);
  if (values.length <= period) return out;

  let gains = 0;
  let losses = 0;
  for (let i = 1; i <= period; i++) {
    const change = values[i] - values[i - 1];
    if (change >= 0) gains += change;
    else losses -= change;
  }
  let avgGain = gains / period;
  let avgLoss = losses / period;

  const rs = avgLoss === 0 ? Number.POSITIVE_INFINITY : avgGain / avgLoss;
  out[period] = 100 - 100 / (1 + rs);

  for (let i = period + 1; i < values.length; i++) {
    const change = values[i] - values[i - 1];
    const gain = Math.max(change, 0);
    const loss = Math.max(-change, 0);
    avgGain = (avgGain * (period - 1) + gain) / period;
    avgLoss = (avgLoss * (period - 1) + loss) / period;
    const rs2 = avgLoss === 0 ? Number.POSITIVE_INFINITY : avgGain / avgLoss;
    out[i] = 100 - 100 / (1 + rs2);
  }

  return out;
}

function bollingerBands(values, period, stdDevMult) {
  if (period <= 0) throw new Error('period must be > 0');
  const upper = new Array(values.length).fill(null);
  const lower = new Array(values.length).fill(null);
  const mid = sma(values, period);

  for (let i = period - 1; i < values.length; i++) {
    const window = values.slice(i - period + 1, i + 1);
    const sd = stddev(window);
    const m = mid[i];
    if (m == null) continue;
    upper[i] = m + stdDevMult * sd;
    lower[i] = m - stdDevMult * sd;
  }

  return { upper, lower, mid };
}

function macd(values, fastPeriod = 12, slowPeriod = 26, signalPeriod = 9) {
  const fast = ema(values, fastPeriod);
  const slow = ema(values, slowPeriod);
  const macdLine = values.map((_, i) => {
    const f = fast[i];
    const s = slow[i];
    return f == null || s == null ? null : f - s;
  });

  const signal = new Array(values.length).fill(null);
  const k = 2 / (signalPeriod + 1);
  let seeded = false;
  let prev = 0;
  const buf = [];

  for (let i = 0; i < macdLine.length; i++) {
    const v = macdLine[i];
    if (v == null) continue;

    if (!seeded) {
      buf.push(v);
      if (buf.length === signalPeriod) {
        const first = mean(buf);
        signal[i] = first;
        prev = first;
        seeded = true;
      }
      continue;
    }

    const next = v * k + prev * (1 - k);
    signal[i] = next;
    prev = next;
  }

  return { macd: macdLine, signal };
}

function toSeries(times, values) {
  return times.map((t, i) => ({ time: t, value: values[i] ?? null }));
}

function isAdmin(cfg, req) {
  if (!cfg.apiAdminSecret) return false;
  const provided = getHeader(req, 'x-admin-secret');
  return typeof provided === 'string' && provided === cfg.apiAdminSecret;
}

async function handler(cfg, req, res) {
  if (req.method === 'OPTIONS') {
    withCors(res, cfg.corsOrigin);
    res.statusCode = 204;
    res.end();
    return;
  }

  const url = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
  const pathname = url.pathname;

  if (req.method === 'GET' && pathname === '/healthz') {
    sendJson(
      res,
      200,
      {
        ok: true,
        version: cfg.appVersion,
        buildTimestamp: cfg.buildTimestamp,
        startedAt: cfg.startedAt,
        ticksTable: cfg.ticksTable,
        candlesFunction: cfg.candlesFunction,
      },
      cfg.corsOrigin
    );
    return;
  }

  if (req.method === 'GET' && pathname === '/v1/chart') {
    const auth = await requireValidToken(cfg, req, 'read');
    if (!auth.ok) {
      sendJson(res, auth.status, { ok: false, error: auth.error }, cfg.corsOrigin);
      return;
    }

    const symbol = (url.searchParams.get('symbol') || '').trim();
    const source = (url.searchParams.get('source') || '').trim();
    const tf = (url.searchParams.get('tf') || url.searchParams.get('timeframe') || '1m').trim();
    const limit = clampInt(url.searchParams.get('limit') || '300', 10, 2000);

    if (!symbol) {
      sendJson(res, 400, { ok: false, error: 'missing_symbol' }, cfg.corsOrigin);
      return;
    }

    let bucketSeconds;
    try {
      bucketSeconds = parseTimeframeToSeconds(tf);
    } catch {
      sendJson(res, 400, { ok: false, error: 'invalid_tf' }, cfg.corsOrigin);
      return;
    }

    const fn = cfg.candlesFunction;
    const query = `
      query Candles($symbol: String!, $bucket: Int!, $limit: Int!, $source: String) {
        ${fn}(args: { p_symbol: $symbol, p_bucket_seconds: $bucket, p_limit: $limit, p_source: $source }) {
          bucket
          open
          high
          low
          close
          oracle_close
          ticks
        }
      }
    `;

    try {
      const data = await hasuraRequest(cfg, { admin: true }, query, {
        symbol,
        bucket: bucketSeconds,
        limit,
        source: source || null,
      });

      const rows = data?.[fn] || [];
      const candles = rows
        .slice()
        .reverse()
        .map((r) => {
          const time = Math.floor(Date.parse(r.bucket) / 1000);
          const open = Number(r.open);
          const high = Number(r.high);
          const low = Number(r.low);
          const close = Number(r.close);
          const oracle = r.oracle_close == null ? null : Number(r.oracle_close);
          const volume = Number(r.ticks || 0);
          return { time, open, high, low, close, volume, oracle };
        })
        .filter((c) => Number.isFinite(c.time) && Number.isFinite(c.open) && Number.isFinite(c.close));

      const times = candles.map((c) => c.time);
      const closes = candles.map((c) => c.close);
      const oracleSeries = toSeries(times, candles.map((c) => (c.oracle == null ? null : c.oracle)));

      const sma20 = toSeries(times, sma(closes, 20));
      const ema20 = toSeries(times, ema(closes, 20));
      const bb = bollingerBands(closes, 20, 2);
      const bbUpper = toSeries(times, bb.upper);
      const bbLower = toSeries(times, bb.lower);
      const bbMid = toSeries(times, bb.mid);
      const rsi14 = toSeries(times, rsi(closes, 14));
      const macdOut = macd(closes, 12, 26, 9);
      const macdLine = toSeries(times, macdOut.macd);
      const macdSignal = toSeries(times, macdOut.signal);

      sendJson(
        res,
        200,
        {
          ok: true,
          version: cfg.appVersion,
          buildTimestamp: cfg.buildTimestamp,
          ticksTable: cfg.ticksTable,
          candlesFunction: cfg.candlesFunction,
          symbol,
          source: source || null,
          tf,
          bucketSeconds,
          candles,
          indicators: {
            oracle: oracleSeries,
            sma20,
            ema20,
            bb20: { upper: bbUpper, lower: bbLower, mid: bbMid },
            rsi14,
            macd: { macd: macdLine, signal: macdSignal },
          },
        },
        cfg.corsOrigin
      );
    } catch (err) {
      sendJson(res, 500, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
    }
    return;
  }

  // Estimate costs for a new contract (read scope).
  // Uses DLOB slippage table and simple fee/tx estimates (inputs).
  if (req.method === 'POST' && pathname === '/v1/contracts/costs/estimate') {
    const auth = await requireValidToken(cfg, req, 'read');
    if (!auth.ok) {
      sendJson(res, auth.status, { ok: false, error: auth.error }, cfg.corsOrigin);
      return;
    }

    let body;
    try {
      body = await readBodyJson(req, { maxBytes: 256 * 1024 });
    } catch (err) {
      const msg = String(err?.message || err);
      if (msg === 'payload_too_large') {
        sendJson(res, 413, { ok: false, error: 'payload_too_large' }, cfg.corsOrigin);
        return;
      }
      sendJson(res, 400, { ok: false, error: 'invalid_json' }, cfg.corsOrigin);
      return;
    }

    const market = String(body?.market_name || body?.market || '').trim();
    if (!market) {
      sendJson(res, 400, { ok: false, error: 'missing_market' }, cfg.corsOrigin);
      return;
    }

    const notionalUsd = parseNumeric(body?.notional_usd ?? body?.notionalUsd ?? body?.size_usd ?? body?.sizeUsd);
    if (notionalUsd == null || !(notionalUsd > 0)) {
      sendJson(res, 400, { ok: false, error: 'invalid_notional_usd' }, cfg.corsOrigin);
      return;
    }

    const sideRaw = String(body?.side || 'long').trim().toLowerCase();
    const entrySide = sideRaw === 'short' || sideRaw === 'sell' ? 'short' : 'long';

    const defaultTakerBps = parseNumeric(process.env.FEE_TAKER_BPS_DEFAULT) ?? 5;
    const defaultMakerBps = parseNumeric(process.env.FEE_MAKER_BPS_DEFAULT) ?? 0;
    const takerBps = clampNumber(parseNumeric(body?.fee_taker_bps) ?? defaultTakerBps, 0, 1000, defaultTakerBps);
    const makerBps = clampNumber(parseNumeric(body?.fee_maker_bps) ?? defaultMakerBps, -1000, 1000, defaultMakerBps);

    const orderType = String(body?.order_type || body?.orderType || 'market').trim().toLowerCase();
    const isMarket = orderType === 'market' || orderType === 'taker';
    const feeBps = isMarket ? takerBps : makerBps;

    let txFeeUsdEst = parseNumeric(body?.tx_fee_usd_est);
    if (txFeeUsdEst == null) {
      const baseLamports = parseNumeric(process.env.TX_BASE_FEE_LAMPORTS_EST) ?? 5000;
      const sigs = parseNumeric(process.env.TX_SIGNATURES_EST) ?? 1;
      const priorityLamports = parseNumeric(process.env.TX_PRIORITY_FEE_LAMPORTS_EST) ?? 0;
      const lamports = Math.max(0, baseLamports) * Math.max(1, sigs) + Math.max(0, priorityLamports);
      const sol = lamports / 1_000_000_000;
      const solUsd = await readSolPriceUsd(cfg);
      txFeeUsdEst = solUsd != null ? sol * solUsd : 0;
    }
    txFeeUsdEst = clampNumber(txFeeUsdEst, 0, 100, 0);

    const defaultReprices = parseNumeric(process.env.EXPECTED_REPRICES_PER_ENTRY_DEFAULT) ?? 0;
    const expectedReprices = clampInt(body?.expected_reprices_per_entry ?? body?.expectedReprices ?? String(defaultReprices), 0, 500);
    const modifyTxCount = clampInt(body?.modify_tx_count ?? body?.modifyTxCount ?? '2', 0, 10);

    const wantedSide = entrySide === 'long' ? 'buy' : 'sell';

    const pickNearest = (rows) => {
      const candidates = (rows || []).filter((r) => String(r.side || '').toLowerCase() === wantedSide);
      let best = null;
      let bestD = Number.POSITIVE_INFINITY;
      for (const r of candidates) {
        const s = parseNumeric(r.size_usd);
        if (s == null) continue;
        const d = Math.abs(s - notionalUsd);
        if (d < bestD) {
          bestD = d;
          best = r;
        }
      }
      return best;
    };

    const fetchSlippageRows = async (tableName) => {
      const query = `
        query Slippage($market: String!, $limit: Int!) {
          ${tableName}(where: {market_name: {_eq: $market}}, order_by: {size_usd: asc}, limit: $limit) {
            market_name
            side
            size_usd
            mid_price
            vwap_price
            worst_price
            impact_bps
            fill_pct
            updated_at
          }
        }
      `;
      const data = await hasuraRequest(cfg, { admin: true }, query, { market, limit: 500 });
      return data?.[tableName] || [];
    };

    try {
      let rows = [];
      let usedTable = null;
      try {
        rows = await fetchSlippageRows('dlob_slippage_latest_v2');
        usedTable = 'dlob_slippage_latest_v2';
      } catch (e) {
        rows = await fetchSlippageRows('dlob_slippage_latest');
        usedTable = 'dlob_slippage_latest';
      }

      const best = pickNearest(rows);
      const impactBps = parseNumeric(best?.impact_bps) ?? 0;
      const slippageUsd = (notionalUsd * impactBps) / 10_000;
      const tradeFeeUsd = (notionalUsd * feeBps) / 10_000;
      const modifyCostUsd = expectedReprices * modifyTxCount * txFeeUsdEst;
      const totalUsd = tradeFeeUsd + slippageUsd + txFeeUsdEst + modifyCostUsd;
      const totalBps = (totalUsd / notionalUsd) * 10_000;

      sendJson(
        res,
        200,
        {
          ok: true,
          input: {
            market_name: market,
            notional_usd: notionalUsd,
            side: entrySide,
            order_type: orderType,
            fee_bps: feeBps,
            tx_fee_usd_est: txFeeUsdEst,
            expected_reprices_per_entry: expectedReprices,
          },
          dlob: best
            ? {
                table: usedTable,
                size_usd: best.size_usd,
                side: best.side,
                mid_price: best.mid_price,
                vwap_price: best.vwap_price,
                impact_bps: best.impact_bps,
                fill_pct: best.fill_pct,
                updated_at: best.updated_at,
              }
            : null,
          breakdown: {
            trade_fee_usd: tradeFeeUsd,
            slippage_usd: slippageUsd,
            tx_fee_usd: txFeeUsdEst,
            expected_modify_usd: modifyCostUsd,
            total_usd: totalUsd,
            total_bps: totalBps,
            breakeven_bps: totalBps,
          },
        },
        cfg.corsOrigin
      );
    } catch (err) {
      sendJson(res, 500, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
    }
    return;
  }

  // Monitor a pushed contract (read scope).
  // Best-effort: if bot tables are not present yet in Hasura schema, return a clear error.
  const monitorMatch = pathname.match(/^\/v1\/contracts\/([0-9a-f-]{36})\/monitor$/i);
  if (req.method === 'GET' && monitorMatch) {
    const auth = await requireValidToken(cfg, req, 'read');
    if (!auth.ok) {
      sendJson(res, auth.status, { ok: false, error: auth.error }, cfg.corsOrigin);
      return;
    }

    const contractId = monitorMatch[1];
    const eventsLimit = clampSeriesLimit(url.searchParams.get('eventsLimit') || '2000', 2000);
    const wantSeries = isTruthy(url.searchParams.get('series') || '');
    const seriesMax = clampSeriesLimit(url.searchParams.get('seriesMax') || '600', 600);

    const pickNum = (obj, keys) => {
      if (!obj || typeof obj !== 'object') return 0;
      for (const k of keys) {
        const v = obj[k];
        const n = parseNumeric(v);
        if (n != null) return n;
      }
      return 0;
    };

    try {
      const q = `
        query ContractMonitor($id: uuid!, $limit: Int!) {
          bot_contracts_by_pk(id: $id) { id }
          bot_events(where: {contract_id: {_eq: $id}}, order_by: {created_at: asc}, limit: $limit) {
            id
            created_at
            type
            payload
          }
        }
      `;
      const data = await hasuraRequest(cfg, { admin: true }, q, { id: contractId, limit: eventsLimit });
      const contract = data?.bot_contracts_by_pk || null;
      const events = Array.isArray(data?.bot_events) ? data.bot_events : [];

      const costs = {
        tradeFeeUsd: 0,
        txFeeUsd: 0,
        slippageUsd: 0,
        fundingUsd: 0,
        realizedPnlUsd: 0,
        totalCostsUsd: 0,
        netPnlUsd: 0,
        txCount: 0,
        fillCount: 0,
        cancelCount: 0,
        modifyCount: 0,
        errorCount: 0,
      };

      const series = [];
      let cumTrade = 0;
      let cumTx = 0;
      let cumSlip = 0;
      let cumFunding = 0;
      let cumRealized = 0;

      for (const ev of events) {
        const payload = ev?.payload && typeof ev.payload === 'object' ? ev.payload : {};
        const type = String(ev?.type || '').toLowerCase();

        const tradeFeeUsd = pickNum(payload, ['trade_fee_usd', 'tradeFeeUsd', 'fee_usd', 'feeUsd']);
        const txFeeUsd = pickNum(payload, ['tx_fee_usd', 'txFeeUsd', 'tx_usd', 'txUsd']);
        const slippageUsd = pickNum(payload, ['slippage_usd', 'slippageUsd', 'impact_usd', 'impactUsd']);
        const fundingUsd = pickNum(payload, ['funding_usd', 'fundingUsd']);
        const realizedPnlUsd = pickNum(payload, ['realized_pnl_usd', 'realizedPnlUsd', 'pnl_usd', 'pnlUsd']);

        const txCount = Math.max(
          0,
          Math.round(
            pickNum(payload, ['tx_count', 'txCount', 'txs', 'txs_count']) ||
              (txFeeUsd > 0 ? 1 : 0)
          )
        );

        cumTrade += tradeFeeUsd;
        cumTx += txFeeUsd;
        cumSlip += slippageUsd;
        cumFunding += fundingUsd;
        cumRealized += realizedPnlUsd;

        costs.tradeFeeUsd = cumTrade;
        costs.txFeeUsd = cumTx;
        costs.slippageUsd = cumSlip;
        costs.fundingUsd = cumFunding;
        costs.realizedPnlUsd = cumRealized;
        costs.txCount += txCount;

        const isFill = type.includes('fill');
        const isCancel = type.includes('cancel');
        const isModify = type.includes('modify') || type.includes('replace') || type.includes('reprice');
        const isError = type.includes('error') || type.includes('panic');

        if (isFill) costs.fillCount += 1;
        if (isCancel) costs.cancelCount += 1;
        if (isModify) costs.modifyCount += 1;
        if (isError) costs.errorCount += 1;

        if (wantSeries) {
          const totalCostsUsd = cumTrade + cumTx + cumSlip + cumFunding;
          const netPnlUsd = cumRealized - totalCostsUsd;
          series.push({
            ts: ev?.created_at || getIsoNow(),
            tradeFeeUsd: cumTrade,
            txFeeUsd: cumTx,
            slippageUsd: cumSlip,
            fundingUsd: cumFunding,
            totalCostsUsd,
            realizedPnlUsd: cumRealized,
            netPnlUsd,
          });
        }
      }

      costs.totalCostsUsd = costs.tradeFeeUsd + costs.txFeeUsd + costs.slippageUsd + costs.fundingUsd;
      costs.netPnlUsd = costs.realizedPnlUsd - costs.totalCostsUsd;

      // Downsample to seriesMax if needed (keep last point).
      let outSeries = null;
      if (wantSeries) {
        if (series.length <= seriesMax) {
          outSeries = series;
        } else {
          const step = Math.max(1, Math.floor(series.length / seriesMax));
          const sampled = [];
          for (let i = 0; i < series.length; i += step) sampled.push(series[i]);
          if (sampled[sampled.length - 1] !== series[series.length - 1]) sampled.push(series[series.length - 1]);
          outSeries = sampled.slice(-seriesMax);
        }
      }

      sendJson(
        res,
        200,
        {
          ok: true,
          contract,
          eventsCount: events.length,
          costs,
          series: outSeries,
        },
        cfg.corsOrigin
      );
    } catch (err) {
      const msg = String(err?.message || err);
      if (msg.includes('bot_contracts') || msg.includes('bot_events')) {
        sendJson(res, 501, { ok: false, error: 'bot_tables_missing' }, cfg.corsOrigin);
        return;
      }
      sendJson(res, 500, { ok: false, error: msg }, cfg.corsOrigin);
    }
    return;
  }

  if (req.method === 'POST' && pathname === '/v1/ingest/tick') {
    const auth = await requireValidToken(cfg, req, 'write');
    if (!auth.ok) {
      sendJson(res, auth.status, { ok: false, error: auth.error }, cfg.corsOrigin);
      return;
    }

    let body;
    try {
      body = await readBodyJson(req, { maxBytes: 1024 * 1024 });
    } catch (err) {
      const msg = String(err?.message || err);
      if (msg === 'payload_too_large') {
        sendJson(res, 413, { ok: false, error: 'payload_too_large' }, cfg.corsOrigin);
        return;
      }
      sendJson(res, 400, { ok: false, error: 'invalid_json' }, cfg.corsOrigin);
      return;
    }

    let tick;
    try {
      tick = normalizeTick(body, auth.token);
    } catch (err) {
      sendJson(res, 400, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
      return;
    }

    try {
      const id = await insertTick(cfg, tick);
      sendJson(res, 200, { ok: true, id }, cfg.corsOrigin);
    } catch (err) {
      sendJson(res, 500, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
    }
    return;
  }

  if (req.method === 'GET' && pathname === '/v1/ticks') {
    const auth = await requireValidToken(cfg, req, 'read');
    if (!auth.ok) {
      sendJson(res, auth.status, { ok: false, error: auth.error }, cfg.corsOrigin);
      return;
    }

    const symbol = url.searchParams.get('symbol') || '';
    const source = url.searchParams.get('source');
    const limitRaw = url.searchParams.get('limit') || '1000';
    const limit = Math.min(5000, Math.max(1, Number.parseInt(limitRaw, 10) || 1000));
    const from = url.searchParams.get('from');
    const to = url.searchParams.get('to');

    if (!symbol.trim()) {
      sendJson(res, 400, { ok: false, error: 'missing_symbol' }, cfg.corsOrigin);
      return;
    }

    const where = { symbol: { _eq: symbol.trim() } };
    if (source && source.trim()) where.source = { _eq: source.trim() };
    if (from || to) {
      where.ts = {};
      if (from) where.ts._gte = from;
      if (to) where.ts._lte = to;
    }

    const table = cfg.ticksTable;
    const query = `
      query Ticks($where: ${table}_bool_exp!, $limit: Int!) {
        ${table}(where: $where, order_by: {ts: desc}, limit: $limit) {
          ts
          market_index
          symbol
          oracle_price
          mark_price
          oracle_slot
          source
        }
      }
    `;

    try {
      const data = await hasuraRequest(cfg, { admin: true }, query, { where, limit });
      const ticks = (data?.[table] || []).slice().reverse();
      sendJson(res, 200, { ok: true, version: cfg.appVersion, ticksTable: cfg.ticksTable, ticks }, cfg.corsOrigin);
    } catch (err) {
      sendJson(res, 500, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
    }
    return;
  }

  if (req.method === 'POST' && pathname === '/v1/admin/tokens') {
    if (!isAdmin(cfg, req)) {
      sendJson(res, 401, { ok: false, error: 'admin_unauthorized' }, cfg.corsOrigin);
      return;
    }

    let body;
    try {
      body = await readBodyJson(req, { maxBytes: 1024 * 1024 });
    } catch {
      sendJson(res, 400, { ok: false, error: 'invalid_json' }, cfg.corsOrigin);
      return;
    }

    const name = (body?.name || 'algo')?.toString?.().trim();
    if (!name) {
      sendJson(res, 400, { ok: false, error: 'missing_name' }, cfg.corsOrigin);
      return;
    }
    const scopes = normalizeScopes(body?.scopes);
    const resolvedScopes = scopes.length ? scopes : ['write'];

    try {
      const { token, row } = await createApiToken(cfg, name, resolvedScopes, body?.meta);
      sendJson(res, 200, { ok: true, token, id: row.id, name: row.name, created_at: row.created_at }, cfg.corsOrigin);
    } catch (err) {
      sendJson(res, 500, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
    }
    return;
  }

  if (req.method === 'POST' && pathname === '/v1/admin/tokens/revoke') {
    if (!isAdmin(cfg, req)) {
      sendJson(res, 401, { ok: false, error: 'admin_unauthorized' }, cfg.corsOrigin);
      return;
    }

    let body;
    try {
      body = await readBodyJson(req, { maxBytes: 1024 * 1024 });
    } catch {
      sendJson(res, 400, { ok: false, error: 'invalid_json' }, cfg.corsOrigin);
      return;
    }

    const id = (body?.id || '')?.toString?.().trim();
    if (!id) {
      sendJson(res, 400, { ok: false, error: 'missing_id' }, cfg.corsOrigin);
      return;
    }

    try {
      const revokedId = await revokeApiToken(cfg, id);
      sendJson(res, 200, { ok: true, id: revokedId }, cfg.corsOrigin);
    } catch (err) {
      sendJson(res, 500, { ok: false, error: String(err?.message || err) }, cfg.corsOrigin);
    }
    return;
  }

  sendJson(res, 404, { ok: false, error: 'not_found' }, cfg.corsOrigin);
}

function main() {
  const cfg = resolveConfig();
  const server = http.createServer((req, res) => void handler(cfg, req, res));

  server.listen(cfg.port, () => {
    console.log(
      JSON.stringify(
        {
          service: 'trade-api',
          version: cfg.appVersion,
          buildTimestamp: cfg.buildTimestamp,
          port: cfg.port,
          hasuraUrl: cfg.hasuraUrl,
          ticksTable: cfg.ticksTable,
          candlesFunction: cfg.candlesFunction,
          hasuraAdminSecret: cfg.hasuraAdminSecret ? '***' : undefined,
          apiAdminSecret: cfg.apiAdminSecret ? '***' : undefined,
        },
        null,
        2
      )
    );
  });
}

main();