const express = require('express');
const { SESSION_TTL, APP, PLEX, TIMEOUTS, buildMediaAuth } = require('../../constants');
const { AuthenticationError, NotFoundError } = require('../errors');

module.exports = function(ctx, getAppSession, appSessionCache) {
  const router = express.Router();

  // Caddy forward_auth gate: checks TOTP session + injects service credentials
  router.get('/auth/gate/:serviceId', ctx.asyncHandler(async (req, res) => {
    res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate');
    const serviceId = req.params.serviceId;

    // Check TOTP session first
    if (ctx.totpConfig.enabled && ctx.totpConfig.sessionDuration !== 'never') {
      const valid = ctx.session.isValid(req);
      if (!valid) return ctx.errorResponse(res, 401, 'Session expired or invalid', { authenticated: false });
    }

    // Session valid (or TOTP disabled) - inject credentials if premium SSO is active
    let injected = false;
    const ssoEnabled = ctx.licenseManager.hasFeature('sso');
    if (!ssoEnabled) {
      // Free tier: TOTP gate passes but no credential injection
      return res.status(200).json({ authenticated: true, credentialsInjected: false, premiumRequired: true });
    }
    try {
      const services = await ctx.servicesStateManager.read();
      const service = services.find(s => s.id === serviceId);

      // External services: inject seedhost Basic Auth
      if (service && service.isExternal) {
        const sharedUser = await ctx.credentialManager.retrieve('seedhost.username').catch(() => null);
        const svcPass = await ctx.credentialManager.retrieve(`seedhost.password.${serviceId}`).catch(() => null);
        const sharedPass = await ctx.credentialManager.retrieve('seedhost.password').catch(() => null);
        const password = svcPass || sharedPass;
        if (sharedUser && password) {
          const basicAuth = Buffer.from(`${sharedUser}:${password}`).toString('base64');
          res.setHeader('Authorization', `Basic ${basicAuth}`);
          injected = true;
          if (service.externalUrl) {
            const appCookies = await getAppSession(serviceId, service.externalUrl, sharedUser, password);
            if (appCookies) res.setHeader('X-App-Cookie', appCookies);
          }
        }
      }

      // Non-external services: check per-service Basic Auth
      if (!service || !service.isExternal) {
        const username = await ctx.credentialManager.retrieve(`service.${serviceId}.username`).catch(() => null);
        const password = await ctx.credentialManager.retrieve(`service.${serviceId}.password`).catch(() => null);
        if (username && password) {
          const basicAuth = Buffer.from(`${username}:${password}`).toString('base64');
          res.setHeader('Authorization', `Basic ${basicAuth}`);
          injected = true;
          if (service && service.url) {
            const appCookies = await getAppSession(serviceId, service.url, username, password);
            if (appCookies) res.setHeader('X-App-Cookie', appCookies);
            if (serviceId === 'plex') {
              const plexCached = appSessionCache.get('plex');
              if (plexCached && plexCached.token) res.setHeader('X-Plex-Token', plexCached.token);
            }
            if (serviceId === 'jellyfin' || serviceId === 'emby') {
              const mediaCached = appSessionCache.get(serviceId);
              if (mediaCached && mediaCached.token) res.setHeader('X-Emby-Token', mediaCached.token);
            }
          }
        }
      }

      // Inject API key
      const arrKey = await ctx.credentialManager.retrieve(`arr.${serviceId}.apikey`).catch(() => null);
      const svcKey = await ctx.credentialManager.retrieve(`service.${serviceId}.apikey`).catch(() => null);
      const apiKey = arrKey || svcKey;
      if (apiKey) { res.setHeader('X-Api-Key', apiKey); injected = true; }
    } catch (e) {
      ctx.log.warn('auth', 'Credential error', { serviceId, error: e.message });
    }

    res.status(200).json({ authenticated: true, credentialsInjected: injected });
  }, 'auth-gate'));

  // Return cached app session token for client-side auth (Premium SSO feature)
  router.get('/auth/app-token/:serviceId', ctx.licenseManager.requirePremium('sso'), ctx.asyncHandler(async (req, res) => {
    const { serviceId } = req.params;

    if (ctx.totpConfig.enabled && ctx.totpConfig.sessionDuration !== 'never') {
      if (!ctx.session.isValid(req)) throw new AuthenticationError('Not authenticated');
    }

    // Jellyfin/Emby: separate browser-specific token
    if (serviceId === 'jellyfin' || serviceId === 'emby') {
      const browserCacheKey = `${serviceId}_browser`;
      const browserCached = appSessionCache.get(browserCacheKey);
      if (browserCached && browserCached.exp > Date.now()) {
        if (browserCached.failed) return ctx.errorResponse(res, 500, 'Login recently failed');
        if (browserCached.token) {
          const resp = { token: browserCached.token };
          if (browserCached.tokenData) Object.assign(resp, browserCached.tokenData);
          return res.json(resp);
        }
      }
      try {
        const username = await ctx.credentialManager.retrieve(`service.${serviceId}.username`).catch(() => null);
        const password = await ctx.credentialManager.retrieve(`service.${serviceId}.password`).catch(() => null);
        if (!username || !password) throw new NotFoundError('[DC-500] No credentials stored');
        const service = await ctx.getServiceById(serviceId);
        const baseUrl = service?.url;
        if (!baseUrl) throw new NotFoundError('No service URL');
        const mediaAuth = buildMediaAuth(APP.DEVICE_IDS.BROWSER);
        const authResp = await ctx.fetchT(`${baseUrl}/Users/AuthenticateByName`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json', 'X-Emby-Authorization': mediaAuth },
          body: JSON.stringify({ Username: username, Pw: password }),
        }, TIMEOUTS.HTTP_LONG);
        const authData = await authResp.json();
        if (authData.AccessToken) {
          const tokenData = { userId: authData.User?.Id, serverId: authData.ServerId, serverName: authData.User?.ServerName || serviceId };
          appSessionCache.set(browserCacheKey, { token: authData.AccessToken, tokenData, exp: Date.now() + SESSION_TTL.TOKEN_SESSION });
          return res.json({ token: authData.AccessToken, ...tokenData });
        }
        return ctx.errorResponse(res, 500, '[DC-501] Authentication failed');
      } catch (e) {
        ctx.log.warn('auth', 'Browser token error', { serviceId, error: e.message });
        return ctx.errorResponse(res, 500, e.message);
      }
    }

    // Check cache first
    const cached = appSessionCache.get(serviceId);
    if (cached && cached.exp > Date.now()) {
      if (cached.failed) return ctx.errorResponse(res, 500, '[DC-501] Login recently failed, retrying in a few minutes');
      if (cached.token) {
        const resp = { token: cached.token };
        if (cached.tokenData) Object.assign(resp, cached.tokenData);
        return res.json(resp);
      }
      const m = cached.cookies.match(/^token=(.+)$/);
      if (m) return res.json({ token: m[1] });
      return res.json({ cookies: cached.cookies });
    }

    // No cache — get fresh session
    try {
      const service = await ctx.getServiceById(serviceId);
      if (!service) throw new NotFoundError('Service not found');
      const baseUrl = service.externalUrl || service.url;
      if (!baseUrl) throw new NotFoundError('No service URL');

      let username, password;
      if (service.isExternal) {
        username = await ctx.credentialManager.retrieve('seedhost.username').catch(() => null);
        const svcPass = await ctx.credentialManager.retrieve(`seedhost.password.${serviceId}`).catch(() => null);
        const sharedPass = await ctx.credentialManager.retrieve('seedhost.password').catch(() => null);
        password = svcPass || sharedPass;
      } else {
        username = await ctx.credentialManager.retrieve(`service.${serviceId}.username`).catch(() => null);
        password = await ctx.credentialManager.retrieve(`service.${serviceId}.password`).catch(() => null);
      }

      if (!username || !password) throw new NotFoundError('[DC-500] No credentials stored');

      const appCookies = await getAppSession(serviceId, baseUrl, username, password);
      if (appCookies) {
        const freshCached = appSessionCache.get(serviceId);
        if (freshCached && freshCached.token) {
          const resp = { token: freshCached.token };
          if (freshCached.tokenData) Object.assign(resp, freshCached.tokenData);
          return res.json(resp);
        }
        const m = appCookies.match(/^token=(.+)$/);
        if (m) return res.json({ token: m[1] });
        return res.json({ cookies: appCookies });
      }

      ctx.errorResponse(res, 500, '[DC-501] Login failed');
    } catch (e) {
      ctx.log.warn('auth', 'App-token error', { error: e.message });
      ctx.errorResponse(res, 500, e.message);
    }
  }, 'auth-app-token'));

  return router;
};