require('dotenv').config();
const fs = require('fs');
const path = require('path');
require('module-alias')({ base: path.resolve(__dirname, '..') });
const cors = require('cors');
const axios = require('axios');
const express = require('express');
const passport = require('passport');
const compression = require('compression');
const cookieParser = require('cookie-parser');
const { logger } = require('@librechat/data-schemas');
const mongoSanitize = require('express-mongo-sanitize');
const {
  isEnabled,
  ErrorController,
  performStartupChecks,
  handleJsonParseError,
  initializeFileStorage,
  GenerationJobManager,
  createStreamServices,
} = require('@librechat/api');
const { connectDb, indexSync } = require('~/db');
const initializeOAuthReconnectManager = require('./services/initializeOAuthReconnectManager');
const createValidateImageRequest = require('./middleware/validateImageRequest');
const { jwtLogin, ldapLogin, passportLogin } = require('~/strategies');
const { updateInterfacePermissions } = require('~/models/interface');
const { checkMigrations } = require('./services/start/migration');
const initializeMCPs = require('./services/initializeMCPs');
const configureSocialLogins = require('./socialLogins');
const { getAppConfig } = require('./services/Config');
const staticCache = require('./utils/staticCache');
const noIndex = require('./middleware/noIndex');
const { seedDatabase } = require('~/models');
const routes = require('./routes');

const { PORT, HOST, ALLOW_SOCIAL_LOGIN, DISABLE_COMPRESSION, TRUST_PROXY } = process.env ?? {};

// Allow PORT=0 to be used for automatic free port assignment
const port = isNaN(Number(PORT)) ? 3080 : Number(PORT);
const host = HOST || 'localhost';
const trusted_proxy = Number(TRUST_PROXY) || 1; /* trust first proxy by default */

const app = express();

const startServer = async () => {
  if (typeof Bun !== 'undefined') {
    axios.defaults.headers.common['Accept-Encoding'] = 'gzip';
  }
  await connectDb();

  logger.info('Connected to MongoDB');
  indexSync().catch((err) => {
    logger.error('[indexSync] Background sync failed:', err);
  });

  app.disable('x-powered-by');
  app.set('trust proxy', trusted_proxy);

  await seedDatabase();
  const appConfig = await getAppConfig();
  initializeFileStorage(appConfig);
  await performStartupChecks(appConfig);
  await updateInterfacePermissions(appConfig);

  const indexPath = path.join(appConfig.paths.dist, 'index.html');
  let indexHTML = fs.readFileSync(indexPath, 'utf8');

  // In order to provide support to serving the application in a sub-directory
  // We need to update the base href if the DOMAIN_CLIENT is specified and not the root path
  if (process.env.DOMAIN_CLIENT) {
    const clientUrl = new URL(process.env.DOMAIN_CLIENT);
    const baseHref = clientUrl.pathname.endsWith('/')
      ? clientUrl.pathname
      : `${clientUrl.pathname}/`;
    if (baseHref !== '/') {
      logger.info(`Setting base href to ${baseHref}`);
      indexHTML = indexHTML.replace(/base href="\/"/, `base href="${baseHref}"`);
    }
  }

  app.get('/health', (_req, res) => res.status(200).send('OK'));

  /* Middleware */
  app.use(noIndex);
  app.use(express.json({ limit: '3mb' }));
  app.use(express.urlencoded({ extended: true, limit: '3mb' }));
  app.use(handleJsonParseError);

  /**
   * Express 5 Compatibility: Make req.query writable for mongoSanitize
   * In Express 5, req.query is read-only by default, but express-mongo-sanitize needs to modify it
   */
  app.use((req, _res, next) => {
    Object.defineProperty(req, 'query', {
      ...Object.getOwnPropertyDescriptor(req, 'query'),
      value: req.query,
      writable: true,
    });
    next();
  });

  app.use(mongoSanitize());
  app.use(cors());
  app.use(cookieParser());

  if (!isEnabled(DISABLE_COMPRESSION)) {
    app.use(compression());
  } else {
    console.warn('Response compression has been disabled via DISABLE_COMPRESSION.');
  }

  app.use(staticCache(appConfig.paths.dist));
  app.use(staticCache(appConfig.paths.fonts));
  app.use(staticCache(appConfig.paths.assets));

  if (!ALLOW_SOCIAL_LOGIN) {
    console.warn('Social logins are disabled. Set ALLOW_SOCIAL_LOGIN=true to enable them.');
  }

  /* OAUTH */
  app.use(passport.initialize());
  passport.use(jwtLogin());
  passport.use(passportLogin());

  /* LDAP Auth */
  if (process.env.LDAP_URL && process.env.LDAP_USER_SEARCH_BASE) {
    passport.use(ldapLogin);
  }

  if (isEnabled(ALLOW_SOCIAL_LOGIN)) {
    await configureSocialLogins(app);
  }

  app.use('/oauth', routes.oauth);
  /* API Endpoints */
  app.use('/api/auth', routes.auth);
  app.use('/api/actions', routes.actions);
  app.use('/api/keys', routes.keys);
  app.use('/api/user', routes.user);
  app.use('/api/search', routes.search);
  app.use('/api/messages', routes.messages);
  app.use('/api/convos', routes.convos);
  app.use('/api/presets', routes.presets);
  app.use('/api/prompts', routes.prompts);
  app.use('/api/categories', routes.categories);
  app.use('/api/endpoints', routes.endpoints);
  app.use('/api/balance', routes.balance);
  app.use('/api/models', routes.models);
  app.use('/api/config', routes.config);
  app.use('/api/assistants', routes.assistants);
  app.use('/api/files', await routes.files.initialize());
  app.use('/images/', createValidateImageRequest(appConfig.secureImageLinks), routes.staticRoute);
  app.use('/api/share', routes.share);
  app.use('/api/roles', routes.roles);
  app.use('/api/agents', routes.agents);
  app.use('/api/banner', routes.banner);
  app.use('/api/memories', routes.memories);
  app.use('/api/permissions', routes.accessPermissions);

  app.use('/api/tags', routes.tags);
  app.use('/api/mcp', routes.mcp);

  app.use(ErrorController);

  app.get('/api/healthSylar', (req, res) => {
    try {
      const healthStatus = {
        status: 'ok',
        timestamp: new Date().toISOString(),
        service: 'librechat-backend',
        version: process.env.LIBRECHAT_VERSION || 'unknown',
        uptime: process.uptime(),
        environment: process.env.NODE_ENV || 'production',
        
        // Information sur la disponibilité du serveur GPU Sylar
        gpu_server: {
          status: 'online', // 'online', 'offline', 'maintenance'
          // Vous pouvez ajouter ici une vérification réelle de disponibilité du serveur GPU
          // en appelant votre endpoint GPU ou en utilisant une variable d'environnement
          base_url: process.env.CUSTOM_API_BASE_URL || process.env.VITE_API_URL || 'unknown',
        },
        
        // Ressources système
        memory: {
          used: Math.round(process.memoryUsage().heapUsed / 1024 / 1024),
          total: Math.round(process.memoryUsage().heapTotal / 1024 / 1024),
          unit: 'MB'
        }
      };
      
      res.status(200).json(healthStatus);
    } catch (error) {
      logger.error('[HealthSylar Check] Error:', error);
      res.status(503).json({
        status: 'error',
        message: 'Service temporarily unavailable',
        timestamp: new Date().toISOString()
      });
    }
  });

  // Health probe for upcoming GPU1 endpoint (returns offline while upstream is down)
  app.get('/api/healthGPU1', async (_req, res) => {
    const started = Date.now();
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 5000);
    try {
      const response = await fetch('https://cpu.lsbuchet.com/healthGPU1', { signal: controller.signal });
      const responseTime = Date.now() - started;

      if (response.ok) {
        const data = await response.json().catch(() => ({}));
        return res.status(200).json({
          status: data.status || 'ok',
          gpu_status: data.gpu_status ?? true,
          responseTime,
          source: 'cpu.lsbuchet.com/healthGPU1',
          payload: data,
        });
      }

      const body = await response.text().catch(() => '');
      return res.status(503).json({
        status: 'offline',
        gpu_status: false,
        responseTime,
        source: 'cpu.lsbuchet.com/healthGPU1',
        message: `HTTP ${response.status}`,
        body,
      });
    } catch (error) {
      const responseTime = Date.now() - started;
      logger.warn('[healthGPU1] fetch failed:', error?.message || error);
      return res.status(503).json({
        status: 'offline',
        gpu_status: false,
        responseTime,
        source: 'cpu.lsbuchet.com/healthGPU1',
        error: error?.message || 'Unknown error',
      });
    } finally {
      clearTimeout(timeout);
    }
  });

  app.get('/api/credits', async (req, res) => {
    const started = Date.now();
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 5000);

    try {
      const response = await fetch('https://cpu.lsbuchet.com/v1/users/credits', {
        signal: controller.signal,
      });
      const responseTime = Date.now() - started;

      if (response.ok) {
        const data = await response.json().catch(() => ({}));
        return res.status(200).json({
          ...data,
          responseTime,
          source: 'cpu.lsbuchet.com/v1/users/credits',
        });
      }

      return res.status(response.status).json({
        error: 'Failed to fetch credits',
        message: `HTTP ${response.status}`,
        responseTime,
        source: 'cpu.lsbuchet.com/v1/users/credits',
      });
    } catch (error) {
      const responseTime = Date.now() - started;
      logger.warn('[credits] fetch failed:', error?.message || error);
      return res.status(503).json({
        error: error?.message || 'Unknown error',
        responseTime,
        source: 'cpu.lsbuchet.com/v1/users/credits',
      });
    } finally {
      clearTimeout(timeout);
    }
  });

  // Proxy endpoint for server toggle
  app.post('/api/server/toggle', async (req, res) => {
    const { state } = req.body;
    const started = Date.now();
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 5000);

    try {
      const response = await fetch('https://cpu.lsbuchet.com/v1/server/toggle', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ state }),
        signal: controller.signal,
      });
      const responseTime = Date.now() - started;

      if (response.ok) {
        const data = await response.json().catch(() => ({}));
        return res.status(200).json({
          ...data,
          responseTime,
          source: 'cpu.lsbuchet.com/v1/server/toggle',
        });
      }

      const errorData = await response.json().catch(() => ({}));
      return res.status(response.status).json({
        ...errorData,
        responseTime,
        source: 'cpu.lsbuchet.com/v1/server/toggle',
      });
    } catch (error) {
      const responseTime = Date.now() - started;
      logger.warn('[server/toggle] fetch failed:', error?.message || error);
      return res.status(503).json({
        error: error?.message || 'Unknown error',
        responseTime,
        source: 'cpu.lsbuchet.com/v1/server/toggle',
      });
    } finally {
      clearTimeout(timeout);
    }
  });

  // Proxy endpoint for CPU status check (conversation-aware)
  app.get('/api/statusCPU', async (req, res) => {
    const conversationId = req.query.conversation_id;
    const started = Date.now();
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 5000);

    try {
      const url = conversationId
        ? `https://cpu.lsbuchet.com/v1/status/cpu?conversation_id=${encodeURIComponent(conversationId)}`
        : 'https://cpu.lsbuchet.com/v1/status/cpu';

      const response = await fetch(url, { signal: controller.signal });
      const responseTime = Date.now() - started;

      if (response.ok) {
        const data = await response.json().catch(() => ({}));
        return res.status(200).json({
          ...data,
          responseTime,
          source: 'cpu.lsbuchet.com/v1/status/cpu',
        });
      }

      return res.status(response.status).json({
        status: 'error',
        message: `HTTP ${response.status}`,
        responseTime,
        source: 'cpu.lsbuchet.com/v1/status/cpu',
      });
    } catch (error) {
      const responseTime = Date.now() - started;
      logger.warn('[statusCPU] fetch failed:', error?.message || error);
      return res.status(503).json({
        status: 'error',
        error: error?.message || 'Unknown error',
        responseTime,
        source: 'cpu.lsbuchet.com/v1/status/cpu',
      });
    } finally {
      clearTimeout(timeout);
    }
  });

  app.use((req, res) => {
    res.set({
      'Cache-Control': process.env.INDEX_CACHE_CONTROL || 'no-cache, no-store, must-revalidate',
      Pragma: process.env.INDEX_PRAGMA || 'no-cache',
      Expires: process.env.INDEX_EXPIRES || '0',
    });

    const lang = req.cookies.lang || req.headers['accept-language']?.split(',')[0] || 'en-US';
    const saneLang = lang.replace(/"/g, '"');
    let updatedIndexHtml = indexHTML.replace(/lang="en-US"/g, `lang="${saneLang}"`);

    res.type('html');
    res.send(updatedIndexHtml);
  });

  app.listen(port, host, async (err) => {
    if (err) {
      logger.error('Failed to start server:', err);
      process.exit(1);
    }

    if (host === '0.0.0.0') {
      logger.info(
        `Server listening on all interfaces at port ${port}. Use http://localhost:${port} to access it`,
      );
    } else {
      logger.info(`Server listening at http://${host == '0.0.0.0' ? 'localhost' : host}:${port}`);
    }

    await initializeMCPs();
    await initializeOAuthReconnectManager();
    await checkMigrations();

    // Configure stream services (auto-detects Redis from USE_REDIS env var)
    const streamServices = createStreamServices();
    GenerationJobManager.configure(streamServices);
    GenerationJobManager.initialize();
  });
};

startServer();

let messageCount = 0;
process.on('uncaughtException', (err) => {
  if (!err.message.includes('fetch failed')) {
    logger.error('There was an uncaught error:', err);
  }

  if (err.message && err.message?.toLowerCase()?.includes('abort')) {
    logger.warn('There was an uncatchable abort error.');
    return;
  }

  if (err.message.includes('GoogleGenerativeAI')) {
    logger.warn(
      '\n\n`GoogleGenerativeAI` errors cannot be caught due to an upstream issue, see: https://github.com/google-gemini/generative-ai-js/issues/303',
    );
    return;
  }

  if (err.message.includes('fetch failed')) {
    if (messageCount === 0) {
      logger.warn('Meilisearch error, search will be disabled');
      messageCount++;
    }

    return;
  }

  if (err.message.includes('OpenAIError') || err.message.includes('ChatCompletionMessage')) {
    logger.error(
      '\n\nAn Uncaught `OpenAIError` error may be due to your reverse-proxy setup or stream configuration, or a bug in the `openai` node package.',
    );
    return;
  }

  if (err.stack && err.stack.includes('@librechat/agents')) {
    logger.error(
      '\n\nAn error occurred in the agents system. The error has been logged and the app will continue running.',
      {
        message: err.message,
        stack: err.stack,
      },
    );
    return;
  }

  process.exit(1);
});

/** Export app for easier testing purposes */
module.exports = app;