// Copyright (c) 2026 Gordon Bolton. MIT License.
const ArrRetriever = require('./ArrRetriever');
const OmbiClient = require('./OmbiClient');
const { logToFile } = require('../utils/logger');

/**
 * Ombi data retriever with caching support.
 * Extends ArrRetriever for PALDRA compliance.
 * Manages Ombi request data and provides lookup maps for efficient matching.
 */
class OmbiRetriever extends ArrRetriever {
  constructor(instanceConfig) {
    super(instanceConfig);
    this.client = new OmbiClient(this.url, this.apiKey);
    this.baseUrl = this.url;
    this.cache = {
      movieRequests: [],
      tvRequests: [],
      users: [],
      movieMap: new Map(), // tmdbId -> request
      tvMap: new Map(),    // tvdbId -> request
      userMap: new Map(),  // id -> user
      lastFetch: 0,
      ttl: 5 * 60 * 1000  // 5 minutes TTL
    };
  }

  /**
   * Get retriever type
   * @returns {string} The retriever type
   */
  getRetrieverType() {
    return 'ombi';
  }

  /**
   * Get the unique instance ID
   * @returns {string} The instance ID
   */
  getInstanceId() {
    return this.id;
  }

  /**
   * Get tags from Ombi (not applicable, returns empty array)
   * @returns {Promise<Array>} Empty array (Ombi doesn't have tags)
   */
  async getTags() {
    return [];
  }

  /**
   * Get queue from Ombi (active requests)
   * @returns {Promise<Object>} Queue object with records array
   */
  async getQueue() {
    await this.refreshCache();
    return {
      records: [...this.cache.movieRequests, ...this.cache.tvRequests]
    };
  }

  /**
   * Get history from Ombi (not applicable, returns empty records)
   * @param {Object} options - Optional parameters (ignored for Ombi)
   * @returns {Promise<Object>} History object with empty records array
   */
  async getHistory(options = {}) {
    return {
      records: []
    };
  }

  /**
   * Test connection to Ombi
   * @returns {Promise<boolean>} True if connection is successful
   */
  async testConnection() {
    return await this.client.testConnection();
  }

  /**
   * Check if cache is expired
   * @returns {boolean} True if cache needs refresh
   */
  isCacheExpired() {
    return Date.now() - this.cache.lastFetch > this.cache.ttl;
  }

  /**
   * Refresh cached data from Ombi API
   * @param {boolean} force - Whether to force a refresh regardless of TTL
   * @returns {Promise<void>}
   */
  async refreshCache(force = false) {
    if (!force && !this.isCacheExpired()) {
      return;
    }

    try {
      logToFile('[OmbiRetriever] Refreshing cache');
      
      // Fetch requests and users in parallel
      const [movieRequests, tvRequests, users] = await Promise.all([
        this.client.getMovieRequests(),
        this.client.getTvRequests(),
        this.client.getUsers()
      ]);

      // Update cache
      this.cache.movieRequests = movieRequests;
      this.cache.tvRequests = tvRequests;
      this.cache.users = users;
      this.cache.lastFetch = Date.now();

      // Build lookup maps
      this.cache.movieMap.clear();
      this.cache.tvMap.clear();
      this.cache.userMap.clear();

      // Build user map (id -> user)
      if (Array.isArray(users)) {
        users.forEach(user => {
          if (user && user.id) {
            this.cache.userMap.set(user.id, user);
          }
        });
      }

      // Build movie map (tmdbId -> request)
      movieRequests.forEach(request => {
        if (request.theMovieDbId) {
          this.cache.movieMap.set(request.theMovieDbId, request);
        }
        if (request.imdbId) {
          this.cache.movieMap.set(request.imdbId, request);
        }
      });

      // Build TV map (tvdbId -> request, fallback to tmdbId)
      tvRequests.forEach(request => {
        if (request.theTvDbId) {
          this.cache.tvMap.set(request.theTvDbId, request);
        }
        if (request.theMovieDbId) {
          this.cache.tvMap.set(request.theMovieDbId, request);
        }
      });

      logToFile(`[OmbiRetriever] Cache refreshed: ${movieRequests.length} movies, ${tvRequests.length} TV shows, ${users.length} users`);
    } catch (error) {
      logToFile(`[OmbiRetriever] Cache refresh failed: ${error.message}`);
      // Don't throw error, continue with stale cache if available
    }
  }

  /**
   * Hydrates requestedUser on a single request using the userMap cache
   * @param {Object} req - The request object
   * @returns {Object} Hydrated request object
   * @private
   */
  _hydrateRequest(req) {
    if (!req) return req;

    let result = req;

    const reqUserId = req.requestedUserId || req.RequestedUserId;
    if (reqUserId && this.cache.userMap.has(reqUserId)) {
      const cachedUser = this.cache.userMap.get(reqUserId);

      let requestedUser = req.requestedUser || req.RequestedUser;

      // If requestedUser is not an object or is empty/null, populate it
      if (!requestedUser || typeof requestedUser !== 'object' || Object.keys(requestedUser).length === 0) {
        const hydratedUser = {
          id: cachedUser.id,
          userName: cachedUser.userName,
          alias: cachedUser.alias || cachedUser.Alias || '',
          userAlias: cachedUser.userAlias || cachedUser.UserAlias || '',
          normalizedUserName: cachedUser.normalizedUserName || cachedUser.NormalizedUserName || ''
        };

        result = {
          ...req,
          requestedUser: hydratedUser,
          RequestedUser: hydratedUser
        };
      }
    }

    // Hydrate childRequests (common for Ombi TV show requests)
    if (Array.isArray(result.childRequests) && result.childRequests.length > 0) {
      const hydratedChildren = result.childRequests.map(child => {
        if (!child) return child;

        const childUserId = child.requestedUserId || child.RequestedUserId;
        if (childUserId && this.cache.userMap.has(childUserId)) {
          const cachedUser = this.cache.userMap.get(childUserId);
          let childUser = child.requestedUser || child.RequestedUser;

          if (!childUser || typeof childUser !== 'object' || Object.keys(childUser).length === 0) {
            const hydratedUser = {
              id: cachedUser.id,
              userName: cachedUser.userName,
              alias: cachedUser.alias || cachedUser.Alias || '',
              userAlias: cachedUser.userAlias || cachedUser.UserAlias || '',
              normalizedUserName: cachedUser.normalizedUserName || cachedUser.NormalizedUserName || ''
            };

            return {
              ...child,
              requestedUser: hydratedUser,
              RequestedUser: hydratedUser
            };
          }
        }
        return child;
      });

      result = { ...result, childRequests: hydratedChildren };
    }

    // Promote requestedDate from childRequests to top level (common for Ombi TV)
    if (!result.requestedDate && Array.isArray(result.childRequests) && result.childRequests.length > 0) {
      const childDate = result.childRequests[0].requestedDate || result.childRequests[0].RequestedDate;
      if (childDate) {
        result = { ...result, requestedDate: childDate };
      }
    }

    return result;
  }

  /**
   * Hydrates requestedUser on a list of requests using the userMap cache
   * @param {Array} requests - Array of request objects
   * @returns {Array} Array of hydrated request objects
   * @private
   */
  _hydrateRequests(requests) {
    if (!Array.isArray(requests)) return [];
    return requests.map(req => this._hydrateRequest(req));
  }

  /**
   * Get all movie requests
   * @param {boolean} force - Whether to force refresh from API
   * @returns {Promise<Array>} Array of movie request objects
   */
  async getMovieRequests(force = false) {
    await this.refreshCache(force);
    return this._hydrateRequests(this.cache.movieRequests);
  }

  /**
   * Get all TV requests
   * @param {boolean} force - Whether to force refresh from API
   * @returns {Promise<Array>} Array of TV request objects
   */
  async getTvRequests(force = false) {
    await this.refreshCache(force);
    return this._hydrateRequests(this.cache.tvRequests);
  }

  /**
   * Find movie request by external ID
   * @param {string} tmdbId - TheMovieDB ID
   * @param {string} imdbId - IMDB ID (optional fallback)
   * @returns {Promise<Object|null>} Request object or null if not found
   */
  async findMovieRequest(tmdbId, imdbId = null) {
    await this.refreshCache();
    
    // Try TMDB ID first
    if (tmdbId && this.cache.movieMap.has(tmdbId)) {
      return this._hydrateRequest(this.cache.movieMap.get(tmdbId));
    }
    
    // Try IMDB ID as fallback
    if (imdbId && this.cache.movieMap.has(imdbId)) {
      return this._hydrateRequest(this.cache.movieMap.get(imdbId));
    }
    
    return null;
  }

  /**
   * Find TV request by external ID
   * @param {string} tvdbId - TheTVDB ID
   * @param {string} tmdbId - TheMovieDB ID (optional fallback)
   * @returns {Promise<Object|null>} Request object or null if not found
   */
  async findTvRequest(tvdbId, tmdbId = null) {
    await this.refreshCache();
    
    // Try TVDB ID first
    if (tvdbId && this.cache.tvMap.has(tvdbId)) {
      return this._hydrateRequest(this.cache.tvMap.get(tvdbId));
    }
    
    // Try TMDB ID as fallback
    if (tmdbId && this.cache.tvMap.has(tmdbId)) {
      return this._hydrateRequest(this.cache.tvMap.get(tmdbId));
    }
    
    return null;
  }

  /**
   * Search for movie by external ID (for fallback when no request found)
   * @param {string} tmdbId - TheMovieDB ID
   * @param {string} imdbId - IMDB ID (optional fallback)
   * @returns {Promise<Object|null>} Search result object or null if not found
   */
  async searchMovie(tmdbId, imdbId = null) {
    if (tmdbId) {
      const result = await this.client.searchMovieByTmdbId(tmdbId);
      if (result) return result;
    }
    
    if (imdbId) {
      const result = await this.client.searchMovieByImdbId(imdbId);
      if (result) return result;
    }
    
    return null;
  }

  /**
   * Search for TV show by external ID (for fallback when no request found)
   * @param {string} tvdbId - TheTVDB ID
   * @param {string} tmdbId - TheMovieDB ID (optional fallback)
   * @returns {Promise<Object|null>} Search result object or null if not found
   */
  async searchTv(tvdbId, tmdbId = null) {
    if (tvdbId) {
      const result = await this.client.searchTvByTvdbId(tvdbId);
      if (result) return result;
    }
    
    if (tmdbId) {
      const result = await this.client.searchTvByTmdbId(tmdbId);
      if (result) return result;
    }
    
    return null;
  }

  /**
   * Get cache statistics
   * @returns {Object} Cache statistics
   */
  getCacheStats() {
    return {
      movieRequests: this.cache.movieRequests.length,
      tvRequests: this.cache.tvRequests.length,
      movieMapSize: this.cache.movieMap.size,
      tvMapSize: this.cache.tvMap.size,
      lastFetch: this.cache.lastFetch,
      age: Date.now() - this.cache.lastFetch
    };
  }
}

module.exports = OmbiRetriever;