const assert = require('assert');
const {
  JAMBONES_MYSQL_HOST,
  JAMBONES_MYSQL_USER,
  JAMBONES_MYSQL_PASSWORD,
  JAMBONES_MYSQL_DATABASE,
  JAMBONES_MYSQL_WRITE_HOST,
  JAMBONES_MYSQL_WRITE_USER,
  JAMBONES_MYSQL_WRITE_PASSWORD,
  JAMBONES_MYSQL_WRITE_DATABASE,
  JAMBONES_MYSQL_WRITE_PORT,
  JAMBONES_REDIS_SENTINEL_MASTER_NAME,
  JAMBONES_REDIS_SENTINELS,
  JAMBONES_REDIS_HOST,
  DRACHTIO_HOST,
  DRACHTIO_PORT,
  DRACHTIO_SECRET,
  JAMBONES_TIME_SERIES_HOST,
  JAMBONES_LOGLEVEL,
  JAMBONES_MYSQL_PORT,
  JAMBONES_MYSQL_CONNECTION_LIMIT,
  NODE_ENV,
  SBC_PUBLIC_ADDRESS_KEEP_ALIVE_IN_MILISECOND
} = require('./lib/config');

assert.ok(JAMBONES_MYSQL_HOST &&
  JAMBONES_MYSQL_USER &&
  JAMBONES_MYSQL_PASSWORD &&
  JAMBONES_MYSQL_DATABASE, 'missing JAMBONES_MYSQL_XXX env vars');
if (JAMBONES_REDIS_SENTINELS) {
  assert.ok(JAMBONES_REDIS_SENTINEL_MASTER_NAME,
    'missing JAMBONES_REDIS_SENTINEL_MASTER_NAME env var, JAMBONES_REDIS_SENTINEL_PASSWORD env var is optional');
} else {
  assert.ok(JAMBONES_REDIS_HOST, 'missing JAMBONES_REDIS_HOST env var');
}
assert.ok(DRACHTIO_HOST, 'missing DRACHTIO_HOST env var');
assert.ok(DRACHTIO_PORT, 'missing DRACHTIO_PORT env var');
assert.ok(DRACHTIO_SECRET, 'missing DRACHTIO_SECRET env var');
assert.ok(JAMBONES_TIME_SERIES_HOST, 'missing JAMBONES_TIME_SERIES_HOST env var');

const CIDRMatcher = require('cidr-matcher');
const logger = require('pino')({ level: JAMBONES_LOGLEVEL || 'info' });
const Srf = require('drachtio-srf');
const srf = new Srf();
const StatsCollector = require('@jambonz/stats-collector');
const stats = new StatsCollector(logger);
const { initLocals, rejectIpv4, checkCache, checkAccountLimits, enforceDeviceLimits } = require('./lib/middleware');
const responseTime = require('drachtio-mw-response-time');
const regParser = require('drachtio-mw-registration-parser');
const Registrar = require('@jambonz/mw-registrar');
const digestChallenge = require('@jambonz/digest-utils');
const debug = require('debug')('jambonz:sbc-registrar');
const {
  pool,
  lookupAuthHook,
  lookupAllVoipCarriers,
  lookupSipGatewaysByCarrier,
  lookupAccountBySipRealm,
  lookupAccountCapacitiesBySid,
  addSbcAddress,
  cleanSbcAddresses,
  updateVoipCarriersRegisterStatus,
  lookupClientByAccountAndUsername,
  lookupSipGatewaysByFilters,
  updateSipGatewayBySid,
  lookupCarrierBySid,
  lookupSystemInformation,
  updateCarrierBySid,
  lookupAccountBySid,
  lookupAuthCarriersForAccountAndSP
} = require('@jambonz/db-helpers')({
  host: JAMBONES_MYSQL_HOST,
  user: JAMBONES_MYSQL_USER,
  port: JAMBONES_MYSQL_PORT || 3306,
  password: JAMBONES_MYSQL_PASSWORD,
  database: JAMBONES_MYSQL_DATABASE,
  connectionLimit: JAMBONES_MYSQL_CONNECTION_LIMIT || 10
}, logger, JAMBONES_MYSQL_WRITE_HOST && JAMBONES_MYSQL_WRITE_USER &&
  JAMBONES_MYSQL_WRITE_PASSWORD && JAMBONES_MYSQL_WRITE_DATABASE ? {
    host: JAMBONES_MYSQL_WRITE_HOST,
    user: JAMBONES_MYSQL_WRITE_USER,
    port: JAMBONES_MYSQL_WRITE_PORT || 3306,
    password: JAMBONES_MYSQL_WRITE_PASSWORD,
    database: JAMBONES_MYSQL_WRITE_DATABASE,
    connectionLimit: JAMBONES_MYSQL_CONNECTION_LIMIT || 10
  } : null);
const {
  writeAlerts,
  AlertType
} = require('@jambonz/time-series')(logger, {
  host: JAMBONES_TIME_SERIES_HOST,
  commitSize: 50,
  commitInterval: 'test' === NODE_ENV ? 7 : 20
});

const {
  client,
  addKey,
  addKeyNx,
  retrieveKey,
  addToSet,
  removeFromSet,
  isMemberOfSet,
  retrieveSet,
  createEphemeralGateway,
  deleteEphemeralGateway
} = require('@jambonz/realtimedb-helpers')({}, logger);

const interval = SBC_PUBLIC_ADDRESS_KEEP_ALIVE_IN_MILISECOND || 900000; // Default 15 minutes

srf.locals = {
  ...srf.locals,
  logger,
  stats,
  pool,
  addToSet, removeFromSet, isMemberOfSet, retrieveSet,
  registrar: new Registrar(logger, client),
  dbHelpers: {
    lookupAccountBySid,
    lookupAuthHook,
    lookupAllVoipCarriers,
    lookupSipGatewaysByCarrier,
    lookupAccountBySipRealm,
    lookupAccountCapacitiesBySid,
    updateVoipCarriersRegisterStatus,
    lookupClientByAccountAndUsername,
    lookupSipGatewaysByFilters,
    updateSipGatewayBySid,
    lookupCarrierBySid,
    lookupSystemInformation,
    updateCarrierBySid,
    lookupAuthCarriersForAccountAndSP
  },
  realtimeDbHelpers: {
    client,
    addKey,
    addKeyNx,
    retrieveKey,
    retrieveSet,
    createEphemeralGateway,
    deleteEphemeralGateway
  },
  writeAlerts,
  AlertType
};
const cidrsEnv = process.env.JAMBONES_NETWORK_CIDR || '192.168.0.0/24,172.16.0.0/16,10.0.0.0/8';
const cidrs = cidrsEnv
  .split(',')
  .map((s) => s.trim());
const matcher = new CIDRMatcher(cidrs);
srf.locals.matcher = matcher;

srf.connect({ host: DRACHTIO_HOST, port: DRACHTIO_PORT, secret: DRACHTIO_SECRET });
let drachtioConnected = false;
let sbcKeepAliveTimer;
srf.on('connect', (err, hp, version, localHostports) => {
  if (err) return logger.error({ err }, 'Error connecting to drachtio server');
  // drachtio-srf re-emits 'connect' on every reconnect; distinguish a reconnect from first connect
  const isReconnect = drachtioConnected;
  drachtioConnected = true;
  logger.info(`connected to drachtio ${version} listening on ${hp}, local hostports: ${localHostports}`);
  srf.locals.drachtioVersion = version || null;

  if (localHostports) {
    const locals = localHostports.split(',');
    for (const hp of locals) {
      const arr = /^(.*)\/(.*):(\d+)$/.exec(hp);
      if (arr && 'tcp' === arr[1] && matcher.contains(arr[2])) {
        const hostport = `${arr[2]}:${arr[3]}`;
        srf.locals.privateSipAddress = hostport;
      }
    }
  }

  // Add SBC Public IP to Database
  srf.locals.sbcPublicIpAddress = {};
  let defaultIp;
  const map = new Map();
  const hostports = hp.split(',');
  for (const hp of hostports) {
    const arr = /^(.*)\/(.*):(\d+)$/.exec(hp);
    if (arr) {
      const ipv4 = arr[2];
      const port = arr[3];
      const addr = map.get(ipv4) || {ipv4};
      switch (arr[1]) {
        case 'udp':
          srf.locals.sbcPublicIpAddress = {
            ...srf.locals.sbcPublicIpAddress,
            udp: `${ipv4}:${port}`
          };
          map.set(ipv4, {...addr, port: port});
          defaultIp = ipv4;
          break;
        case 'tls':
          map.set(ipv4, {...addr, tls_port: port});
          srf.locals.sbcPublicIpAddress = {
            ...srf.locals.sbcPublicIpAddress,
            tls: `${ipv4}:${port}`
          };
          break;
        case 'wss':
          srf.locals.sbcPublicIpAddress = {
            ...srf.locals.sbcPublicIpAddress,
            wss: `${ipv4}:${port}`
          };
          map.set(ipv4, {...addr, wss_port: port});
          break;
      }
    }
  }

  // if drachtio server does not tell us the tls ip and port default to standard 5061
  if (!srf.locals.sbcPublicIpAddress.tls) {
    srf.locals.sbcPublicIpAddress.tls = `${defaultIp}:5061`;
  }

  logger.info({sbcPublicIpAddress: srf.locals.sbcPublicIpAddress}, 'sbc public ip addresses');

  // Function to check if the IP address is in a private subnet (RFC 1918)
  const isPrivateSubnet = (ip) => {
    const [firstOctet, secondOctet] = ip.split('.').map(Number);
    return (
      (firstOctet === 10) || // 10.0.0.0/8
      (firstOctet === 172 && secondOctet >= 16 && secondOctet <= 31) || // 172.16.0.0/12
      (firstOctet === 192 && secondOctet === 168) // 192.168.0.0/16
    );
  };

  logger.info({ips: [...map.entries()]}, 'drachtio sip contacts');
  const mapOfPublicAddresses = map.size === 0 ? map : new Map(Array.from(
    map.entries())
    .filter(([key, value]) => !isPrivateSubnet(key)));

  logger.info({ips: [...mapOfPublicAddresses.entries()]}, 'drachtio sip public contacts');

  /* Register this SBC's public addresses and keep them alive.
     addSbcAddress() refreshes the row's last_updated, and cleanSbcAddresses() (run here and by
     every other sidecar in the cluster) deletes rows older than DEAD_SBC_IN_SECOND, so the
     refresh MUST recur for as long as this process lives.  We reap stale rows only after
     refreshing our own, so the cleaner can never run ahead of this SBC's first keepalive. */
  const sbcKeepAlive = async() => {
    for (const addr of mapOfPublicAddresses.values()) {
      await addSbcAddress(addr.ipv4, addr.port, addr.tls_port, addr.wss_port);
    }
    await cleanSbcAddresses();
  };
  sbcKeepAlive();
  // drachtio re-emits 'connect' on reconnect (possibly with different contacts): replace, don't stack
  if (sbcKeepAliveTimer) clearInterval(sbcKeepAliveTimer);
  sbcKeepAliveTimer = setInterval(sbcKeepAlive, interval);
  sbcKeepAliveTimer.unref();

  /* start regbot */
  require('./lib/sip-trunk-register')(logger, srf);
  // Start Options bot
  require('./lib/sip-trunk-options-ping')(logger, srf);

  /* on a reconnect after a drachtio restart, the initial startup above is a no-op
     (guarded by `initialized`), so force the surviving regbots to re-register */
  if (isReconnect) {
    logger.info('drachtio reconnected — resyncing regbots');
    // eslint-disable-next-line promise/no-promise-in-callback
    require('./lib/sip-trunk-register').resync(logger, srf)
      .catch((e) => logger.error({ err: e }, 'regbot resync after reconnect failed'));
  }
});

if (NODE_ENV === 'test') {
  srf.on('error', (err) => {
    logger.info(err, 'Error connecting to drachtio');
  });
}

const rttMetric = (req, res, time) => {
  if (res.cached) {
    stats.histogram('sbc.registration.cached.response_time', time.toFixed(0), [`status:${res.statusCode}`]);
  }
  else {
    stats.histogram('sbc.registration.total.response_time', time.toFixed(0), [`status:${res.statusCode}`]);
  }
};

// middleware
srf.use('register', [
  initLocals,
  responseTime(rttMetric),
  rejectIpv4,
  regParser,
  checkCache,
  checkAccountLimits,
  digestChallenge,
  enforceDeviceLimits]);

srf.use('options', [
  initLocals
]);

srf.register(require('./lib/register')({logger}));
srf.options(require('./lib/options')({srf, logger}));

// Start CLI runtime config server with access to srf.locals
require('./lib/cli/runtime-config').initialize(srf.locals, logger);

setInterval(async() => {
  const count = await srf.locals.registrar.getCountOfUsers();
  debug(`count of registered users: ${count}`);
  stats.gauge('sbc.users.count', parseInt(count));
}, 30000);

module.exports = { srf, logger };