import app from './app';
import { env, initEnv } from './config/env';
import { refreshAllKeys, startKeyRotation, stopKeyRotation } from './services/key-rotation.service';
import { isCryptoReady, decryptMnemonic, encryptMnemonic } from './services/crypto.service';
import { db } from './config/database';
import { pingRedis, closeRedis } from './config/redis';
import { logger } from './lib/logger';

// Global error handlers — иначе unhandled errors идут в stderr без sanitization (leak secrets)
process.on('unhandledRejection', (reason: any) => {
  logger.error(`Unhandled rejection: ${reason?.stack || reason?.message || reason}`);
});
process.on('uncaughtException', (err: Error) => {
  logger.error(`Uncaught exception: ${err.stack || err.message}`);
  // Process state could be corrupt — exit cleanly
  process.exit(1);
});

async function main() {
  logger.info(`Wallet service instance started with id ${logger.instanceId}`);

  await initEnv();
  const refreshResult = await refreshAllKeys();
  if (!refreshResult.ok) {
    logger.error(`Initial Vault refresh failed: ${refreshResult.reason}. Refusing to start.`);
    process.exit(1);
  }

  // Custodial: без master-key сервис не может расшифровать ни одну мнемонику — fail fast.
  if (!isCryptoReady()) {
    logger.error('Crypto master key not loaded — refusing to start (custodial wallets require it)');
    process.exit(1);
  }

  // Integrity self-test: если в БД уже есть encrypted_mnemonic, master-key должен их декриптить.
  // Иначе мы стартовали с НЕПРАВИЛЬНЫМ ключом (например после потери Vault dev-mode state) —
  // и любой /send или /sign будет тихо валиться с GCM auth error. Лучше упасть сразу.
  await runCryptoIntegritySelfTest();

  // KeyDB / Redis ping — idempotency critical для money flow; fail-fast если недоступен.
  try {
    await pingRedis();
    logger.info('KeyDB/Redis self-test: PASSED');
  } catch (err: any) {
    logger.error(`KeyDB/Redis ping failed: ${err.message}. Refusing to start (idempotency unavailable).`);
    process.exit(1);
  }

  startKeyRotation();

  const server = app.listen(env.port, () => {
    logger.info(`Server running on port ${env.port}`);
  });

  const shutdown = (signal: string) => {
    logger.info(`${signal} received, shutting down gracefully`);
    stopKeyRotation();
    void closeRedis();
    server.close(() => process.exit(0));
    // Force exit if shutdown takes too long
    setTimeout(() => process.exit(1), 10_000).unref();
  };

  process.on('SIGTERM', () => shutdown('SIGTERM'));
  process.on('SIGINT', () => shutdown('SIGINT'));
}

async function runCryptoIntegritySelfTest(): Promise<void> {
  // H4 — Two checks:
  //   (a) AES round-trip ALWAYS (даже на пустой DB): encrypt PROBE → decrypt → equal.
  //       Защита от corrupted master-key buffer (wrong size, zeros, etc.)
  //   (b) Если в БД есть encrypted_mnemonic — пытаемся декриптить (sample 3 rows).
  //       Защита от master-key drift (Vault rotation accidental).

  // (a) AES round-trip
  try {
    const probe = 'self-test-PROBE-string-with-some-length-for-realism';
    const ct = encryptMnemonic(probe);
    const pt = decryptMnemonic(ct);
    if (pt !== probe) {
      logger.error('Crypto self-test: AES round-trip MISMATCH — master-key buffer corrupt');
      process.exit(1);
    }
  } catch (err: any) {
    logger.error(`Crypto self-test: AES round-trip failed: ${err?.message}`);
    process.exit(1);
  }

  // (b) Existing-blob compatibility
  try {
    const rows = await db('users')
      .whereNotNull('encrypted_mnemonic')
      .select('encrypted_mnemonic')
      .limit(3);

    if (rows.length === 0) {
      logger.info('Crypto self-test: PASSED (round-trip OK, no existing blobs to check)');
      return;
    }

    for (const row of rows) {
      try {
        decryptMnemonic(row.encrypted_mnemonic);
      } catch (err: any) {
        logger.error(
          'Crypto self-test: FAILED — master-key DOES NOT match stored encrypted_mnemonic. ' +
          'Likely cause: Vault state was lost (dev-mode in-memory) and a different key was seeded. ' +
          'Recovery: restore seed-cache.env from .seed-backup/ OR wipe DB with `docker compose down -v`. ' +
          `Underlying: ${err?.message}`,
        );
        process.exit(1);
      }
    }
    logger.info(`Crypto self-test: PASSED (round-trip OK + ${rows.length} existing blob(s) decryptable)`);
  } catch (err: any) {
    logger.error(`Crypto self-test: could not query DB: ${err?.message}`);
    process.exit(1);
  }
}

main().catch((err) => {
  logger.error(`Failed to start: ${err.message}`);
  process.exit(1);
});