/**
 * SIP proxy — hub model entry point.
 *
 * Thin bootstrap that wires together:
 * - UDP socket for all SIP signaling
 * - CallManager (the hub model core)
 * - Provider registration
 * - Local device registrar
 * - WebRTC signaling
 * - Web dashboard
 * - Rust codec bridge
 *
 * All call/media logic lives in ts/call/.
 */

import dgram from 'node:dgram';
import fs from 'node:fs';
import path from 'node:path';
import { Buffer } from 'node:buffer';

import { SipMessage } from './sip/index.ts';
import type { IEndpoint } from './sip/index.ts';
import { loadConfig, resolveOutboundRoute } from './config.ts';
import type { IAppConfig, IProviderConfig } from './config.ts';
import {
  initProviderStates,
  syncProviderStates,
  getProviderByUpstreamAddress,
  handleProviderRegistrationResponse,
} from './providerstate.ts';
import {
  initRegistrar,
  handleDeviceRegister,
  isKnownDeviceAddress,
  getAllDeviceStatuses,
} from './registrar.ts';
import { broadcastWs, initWebUi } from './frontend.ts';
import {
  initWebRtcSignaling,
  sendToBrowserDevice,
  getAllBrowserDeviceIds,
  getBrowserDeviceWs,
} from './webrtcbridge.ts';
import { initCodecBridge } from './opusbridge.ts';
import { initAnnouncement } from './announcement.ts';
import { CallManager } from './call/index.ts';
import { PromptCache } from './call/prompt-cache.ts';
import { VoiceboxManager } from './voicebox.ts';

// ---------------------------------------------------------------------------
// Config
// ---------------------------------------------------------------------------

let appConfig: IAppConfig = loadConfig();
const { proxy } = appConfig;

const LAN_IP   = proxy.lanIp;
const LAN_PORT = proxy.lanPort;

const LOG_PATH = path.join(process.cwd(), 'sip_trace.log');

// ---------------------------------------------------------------------------
// Logging
// ---------------------------------------------------------------------------

const startTime = Date.now();
const instanceId = `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;

function now(): string {
  return new Date().toISOString().replace('T', ' ').slice(0, 19);
}

function log(msg: string): void {
  const line = `${now()} ${msg}\n`;
  fs.appendFileSync(LOG_PATH, line);
  process.stdout.write(line);
  broadcastWs('log', { message: msg });
}

function logPacket(label: string, data: Buffer): void {
  const head = `\n========== ${now()} ${label} (${data.length}b) ==========\n`;
  const looksText = data.length > 0 && data[0] >= 0x41 && data[0] <= 0x7a;
  const body = looksText
    ? data.toString('utf8')
    : `[${data.length} bytes binary] ${data.toString('hex').slice(0, 80)}`;
  fs.appendFileSync(LOG_PATH, head + body + '\n');
}

// ---------------------------------------------------------------------------
// Initialize subsystems
// ---------------------------------------------------------------------------

const providerStates = initProviderStates(appConfig.providers, proxy.publicIpSeed);

initRegistrar(appConfig.devices, log);

// Initialize voicemail and IVR subsystems.
const promptCache = new PromptCache(log);
const voiceboxManager = new VoiceboxManager(log);
voiceboxManager.init(appConfig.voiceboxes ?? []);

const callManager = new CallManager({
  appConfig,
  sendSip: (buf, dest) => sock.send(buf, dest.port, dest.address),
  log,
  broadcastWs,
  getProviderState: (id) => providerStates.get(id),
  getAllBrowserDeviceIds,
  sendToBrowserDevice,
  getBrowserDeviceWs,
  promptCache,
  voiceboxManager,
});

// Initialize WebRTC signaling (browser device registration only).
initWebRtcSignaling({ log });

// ---------------------------------------------------------------------------
// Status snapshot (fed to web dashboard)
// ---------------------------------------------------------------------------

function getStatus() {
  const providers: unknown[] = [];
  for (const ps of providerStates.values()) {
    providers.push({
      id: ps.config.id,
      displayName: ps.config.displayName,
      registered: ps.isRegistered,
      publicIp: ps.publicIp,
    });
  }

  return {
    instanceId,
    uptime: Math.floor((Date.now() - startTime) / 1000),
    lanIp: LAN_IP,
    providers,
    devices: getAllDeviceStatuses(),
    calls: callManager.getStatus(),
    callHistory: callManager.getHistory(),
    contacts: appConfig.contacts || [],
    voicemailCounts: voiceboxManager.getAllUnheardCounts(),
  };
}

// ---------------------------------------------------------------------------
// Main UDP socket
// ---------------------------------------------------------------------------

const sock = dgram.createSocket('udp4');

sock.on('message', (data: Buffer, rinfo: dgram.RemoteInfo) => {
  try {
    const ps = getProviderByUpstreamAddress(rinfo.address, rinfo.port);

    const msg = SipMessage.parse(data);
    if (!msg) {
      // Non-SIP data — forward raw based on direction.
      if (ps) {
        // From provider, forward to... nowhere useful without a call context.
        logPacket(`UP->DN RAW (unparsed) from ${rinfo.address}:${rinfo.port}`, data);
      } else {
        // From device, forward to default provider.
        const dp = resolveOutboundRoute(appConfig, '');
        if (dp) sock.send(data, dp.provider.outboundProxy.port, dp.provider.outboundProxy.address);
      }
      return;
    }

    // 1. Provider registration responses — consumed by providerstate.
    if (handleProviderRegistrationResponse(msg)) return;

    // 2. Device REGISTER — handled by local registrar.
    if (!ps && msg.method === 'REGISTER') {
      const response = handleDeviceRegister(msg, { address: rinfo.address, port: rinfo.port });
      if (response) {
        sock.send(response.serialize(), rinfo.port, rinfo.address);
        return;
      }
    }

    // 3. Route to existing call by SIP Call-ID.
    if (callManager.routeSipMessage(msg, rinfo)) {
      return;
    }

    // 4. New inbound call from provider.
    if (ps && msg.isRequest && msg.method === 'INVITE') {
      logPacket(`[new inbound] INVITE from ${rinfo.address}:${rinfo.port}`, data);

      // Detect public IP from Via.
      const via = msg.getHeader('Via');
      if (via) ps.detectPublicIp(via);

      callManager.createInboundCall(ps, msg, { address: rinfo.address, port: rinfo.port });
      return;
    }

    // 5. New outbound call from device (passthrough).
    if (!ps && msg.isRequest && msg.method === 'INVITE') {
      logPacket(`[new outbound] INVITE from ${rinfo.address}:${rinfo.port}`, data);
      const dialedNumber = SipMessage.extractUri(msg.requestUri || '') || '';
      const routeResult = resolveOutboundRoute(
        appConfig,
        dialedNumber,
        undefined,
        (pid) => !!providerStates.get(pid)?.registeredAor,
      );
      if (routeResult) {
        const provState = providerStates.get(routeResult.provider.id);
        if (provState) {
          // Apply number transformation to the INVITE if needed.
          if (routeResult.transformedNumber !== dialedNumber) {
            const newUri = msg.requestUri?.replace(dialedNumber, routeResult.transformedNumber);
            if (newUri) msg.setRequestUri(newUri);
          }
          callManager.handlePassthroughOutbound(msg, { address: rinfo.address, port: rinfo.port }, routeResult.provider, provState);
        }
      }
      return;
    }

    // 6. Fallback: forward based on direction (for mid-dialog messages
    //    that don't match any tracked call, e.g. OPTIONS, NOTIFY).
    if (ps) {
      // From provider -> forward to device.
      logPacket(`[fallback inbound] from ${rinfo.address}:${rinfo.port}`, data);
      const via = msg.getHeader('Via');
      if (via) ps.detectPublicIp(via);
      // Try to figure out where to send it...
      // For now, just log. These should become rare once all calls are tracked.
      log(`[fallback] unrouted inbound ${msg.isRequest ? msg.method : msg.statusCode} Call-ID=${msg.callId.slice(0, 30)}`);
    } else {
      // From device -> forward to provider.
      logPacket(`[fallback outbound] from ${rinfo.address}:${rinfo.port}`, data);
      const fallback = resolveOutboundRoute(appConfig, '');
      if (fallback) sock.send(msg.serialize(), fallback.provider.outboundProxy.port, fallback.provider.outboundProxy.address);
    }
  } catch (e: any) {
    log(`[err] ${e?.stack || e}`);
  }
});

sock.on('error', (err: Error) => log(`[main] sock err: ${err.message}`));

sock.bind(LAN_PORT, '0.0.0.0', () => {
  const providerList = appConfig.providers.map((p) => p.displayName).join(', ');
  const deviceList = appConfig.devices.map((d) => d.displayName).join(', ');
  log(`sip proxy bound 0.0.0.0:${LAN_PORT} | providers: ${providerList} | devices: ${deviceList}`);

  // Start upstream provider registrations.
  for (const ps of providerStates.values()) {
    ps.startRegistration(
      LAN_IP,
      LAN_PORT,
      (buf, dest) => sock.send(buf, dest.port, dest.address),
      log,
      (provider) => broadcastWs('registration', { providerId: provider.config.id, registered: provider.isRegistered }),
    );
  }

  // Initialize audio codec bridge (Rust binary via smartrust).
  initCodecBridge(log)
    .then(() => initAnnouncement(log))
    .then(async () => {
      // Pre-generate voicemail beep tone.
      await promptCache.generateBeep('voicemail-beep', 1000, 500, 8000);

      // Pre-generate voicemail greetings for all configured voiceboxes.
      for (const vb of appConfig.voiceboxes ?? []) {
        if (!vb.enabled) continue;
        const promptId = `voicemail-greeting-${vb.id}`;
        const wavPath = vb.greetingWavPath;
        if (wavPath) {
          await promptCache.loadWavPrompt(promptId, wavPath);
        } else {
          const text = vb.greetingText || 'The person you are trying to reach is not available. Please leave a message after the tone.';
          await promptCache.generatePrompt(promptId, text, vb.greetingVoice || 'af_bella');
        }
      }

      // Pre-generate IVR menu prompts.
      if (appConfig.ivr?.enabled) {
        for (const menu of appConfig.ivr.menus) {
          const promptId = `ivr-menu-${menu.id}`;
          await promptCache.generatePrompt(promptId, menu.promptText, menu.promptVoice || 'af_bella');
        }
      }

      log(`[startup] prompts cached: ${promptCache.listIds().join(', ') || 'none'}`);
    })
    .catch((e) => log(`[codec] init failed: ${e}`));
});

// ---------------------------------------------------------------------------
// Web UI
// ---------------------------------------------------------------------------

initWebUi(
  getStatus,
  log,
  (number, deviceId, providerId) => {
    const call = callManager.createOutboundCall(number, deviceId, providerId);
    return call ? { id: call.id } : null;
  },
  (callId) => callManager.hangup(callId),
  () => {
    // Reload config after UI save.
    try {
      const fresh = loadConfig();
      Object.assign(appConfig, fresh);
      // Sync provider registrations: add new, remove deleted, re-register changed.
      syncProviderStates(
        fresh.providers,
        proxy.publicIpSeed,
        LAN_IP,
        LAN_PORT,
        (buf, dest) => sock.send(buf, dest.port, dest.address),
        log,
        (provider) => broadcastWs('registration', { providerId: provider.config.id, registered: provider.isRegistered }),
      );
      log('[config] reloaded config after save');
    } catch (e: any) {
      log(`[config] reload failed: ${e.message}`);
    }
  },
  callManager,
  voiceboxManager,
);

process.on('SIGINT', () => { log('SIGINT, exiting'); process.exit(0); });
process.on('SIGTERM', () => { log('SIGTERM, exiting'); process.exit(0); });