const { Game } = require('../models');
const { cacheUtils } = require('../config/redis');
const { sequelize } = require('../config/database');
const { Op, Sequelize } = require('sequelize');

/**
 * Game Controller - Quản lý trò chơi giáo dục
 */
class GameController {
  /**
   * Get all games with pagination
   */
  async getAllGames(req, res, next) {
    try {
      const { page = 1, limit = 20, type, is_active, is_premium, difficulty_level } = req.query;
      const offset = (page - 1) * limit;
      
      const cacheKey = `games:list:${page}:${limit}:${type || 'all'}:${is_active || 'all'}:${is_premium || 'all'}:${difficulty_level || 'all'}`;
      
      const cached = await cacheUtils.get(cacheKey);
      /*
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      */
      
      const where = {};
      if (type) where.type = type;
      if (is_active !== undefined) where.is_active = is_active === 'true';
      if (is_premium !== undefined) where.is_premium = is_premium === 'true';
      if (difficulty_level) where.difficulty_level = difficulty_level;
      
      const { count, rows } = await Game.findAndCountAll({
        where,
        limit: parseInt(limit),
        offset: parseInt(offset),
        order: [['display_order', 'ASC'], ['rating', 'DESC']],
      });
      
      const result = {
        games: rows,
        pagination: {
          total: count,
          page: parseInt(page),
          limit: parseInt(limit),
          totalPages: Math.ceil(count / limit),
        },
      };
      
      await cacheUtils.set(cacheKey, result, 1800);
      
      res.json({
        success: true,
        data: result,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get game by ID
   */
  async getGameById(req, res, next) {
    try {
      const { id } = req.params;
      const cacheKey = `game:${id}`;
      
      const cached = await cacheUtils.get(cacheKey);
      /*
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      */
      const game = await Game.findByPk(id);
      
      if (!game) {
        return res.status(404).json({
          success: false,
          message: 'Game not found',
        });
      }
      
      await cacheUtils.set(cacheKey, game, 3600);
      
      res.json({
        success: true,
        data: game,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Create new game
   */
  async createGame(req, res, next) {
    try {
      const {
        title,
        description,
        url,
        thumbnail,
        type,
        config,
        is_active,
        is_premium,
        min_grade,
        max_grade,
        difficulty_level,
        display_order,
      } = req.body;
      
      // Validate required fields
      if (!title || !url || !type) {
        return res.status(400).json({
          success: false,
          message: 'title, url, and type are required',
        });
      }
      
      const game = await Game.create({
        title,
        description,
        url,
        thumbnail,
        type,
        config: config || {},
        is_active: is_active !== undefined ? is_active : true,
        is_premium: is_premium !== undefined ? is_premium : false,
        min_grade,
        max_grade,
        difficulty_level,
        display_order: display_order || 0,
        play_count: 0,
      });
      
      // Clear cache
      await cacheUtils.deletePattern('games:*');
      
      res.status(201).json({
        success: true,
        data: game,
        message: 'Game created successfully',
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Update game
   */
  async updateGame(req, res, next) {
    try {
      const { id } = req.params;
      const {
        title,
        description,
        url,
        thumbnail,
        type,
        config,
        is_active,
        is_premium,
        min_grade,
        max_grade,
        difficulty_level,
        display_order,
        rating,
      } = req.body;
      
      const game = await Game.findByPk(id);
      
      if (!game) {
        return res.status(404).json({
          success: false,
          message: 'Game not found',
        });
      }
      
      await game.update({
        ...(title !== undefined && { title }),
        ...(description !== undefined && { description }),
        ...(url !== undefined && { url }),
        ...(thumbnail !== undefined && { thumbnail }),
        ...(type !== undefined && { type }),
        ...(config !== undefined && { config }),
        ...(is_active !== undefined && { is_active }),
        ...(is_premium !== undefined && { is_premium }),
        ...(min_grade !== undefined && { min_grade }),
        ...(max_grade !== undefined && { max_grade }),
        ...(difficulty_level !== undefined && { difficulty_level }),
        ...(display_order !== undefined && { display_order }),
        ...(rating !== undefined && { rating }),
      });
      
      // Clear cache
      await cacheUtils.deletePattern('games:*');
      await cacheUtils.deletePattern(`game:${id}`);
      
      res.json({
        success: true,
        data: game,
        message: 'Game updated successfully',
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Delete game
   */
  async deleteGame(req, res, next) {
    try {
      const { id } = req.params;
      
      const game = await Game.findByPk(id);
      
      if (!game) {
        return res.status(404).json({
          success: false,
          message: 'Game not found',
        });
      }
      
      await game.destroy();
      
      // Clear cache
      await cacheUtils.deletePattern('games:*');
      await cacheUtils.deletePattern(`game:${id}`);
      
      res.json({
        success: true,
        message: 'Game deleted successfully',
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Increment play count
   */
  async incrementPlayCount(req, res, next) {
    try {
      const { id } = req.params;
      
      const game = await Game.findByPk(id);
      
      if (!game) {
        return res.status(404).json({
          success: false,
          message: 'Game not found',
        });
      }
      
      await game.increment('play_count');
      await game.reload();
      
      // Clear cache
      await cacheUtils.deletePattern(`game:${id}`);
      
      res.json({
        success: true,
        data: {
          id: game.id,
          play_count: game.play_count,
        },
        message: 'Play count incremented',
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get games by type (for lesson matching)
   */
  async getGamesByType(req, res, next) {
    try {
      const { type } = req.params;
      const { only_active = 'true' } = req.query;
      
      const cacheKey = `games:type:${type}:${only_active}`;
      
      const cached = await cacheUtils.get(cacheKey);
      /*
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      */
      const where = { type };
      if (only_active === 'true') where.is_active = true;
      
      const games = await Game.findAll({
        where,
        order: [['display_order', 'ASC'], ['rating', 'DESC']],
      });
      
      await cacheUtils.set(cacheKey, games, 3600);
      
      res.json({
        success: true,
        data: games,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Create or Update game with URL check
   * Nếu body có id: update game đó
   * Nếu body không có id: kiểm tra URL có tồn tại trong DB không, chưa có thì lưu mới
   */
  async createGameWithUrlCheck(req, res, next) {
    try {
      const {
        id,
        title,
        description,
        url,
        thumbnail,
        type,
        config,
        is_active,
        is_premium,
        min_grade,
        max_grade,
        difficulty_level,
        display_order,
        rating,
      } = req.body;

      // Validate required fields
      if (!title || !url || !type) {
        return res.status(400).json({
          success: false,
          message: 'title, url, and type are required',
        });
      }

      // Check if URL already exists in DB
      const existingGame = await Game.findOne({ where: { url } });
      if (existingGame) {
        return res.status(200).json({
          success: true,
          data: null,
          message: 'URL đã tồn tại, game không được lưu',
        });
      }

      // Create new game (with id if provided, or auto-generate)
      const game = await Game.create({
        ...(id && { id }),
        title,
        description,
        url,
        thumbnail,
        type,
        config: config || {},
        is_active: is_active !== undefined ? is_active : true,
        is_premium: is_premium !== undefined ? is_premium : false,
        min_grade,
        max_grade,
        difficulty_level,
        display_order: display_order || 0,
        play_count: 0,
      });

      // Clear cache
      await cacheUtils.deletePattern('games:*');

      res.status(201).json({
        success: true,
        data: game,
        message: 'Game created successfully',
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get all unique game types
   */
  async getGameTypes(req, res, next) {
    try {
      const cacheKey = 'games:types';
      
      const cached = await cacheUtils.get(cacheKey);
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }

      // Get all games with only type field
      const games = await Game.findAll({
        attributes: [[Sequelize.fn('DISTINCT', Sequelize.col('type')), 'type']],
        where: {
          type: {
            [Op.and]: [
              { [Op.ne]: null },
              { [Op.notIn]: ['', ' '] }
            ]
          }
        },
        raw: true,
      });

      // Get distinct types
      const result = games.filter(g => g.type);

      await cacheUtils.set(cacheKey, result, 3600);

      res.json({
        success: true,
        data: result,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Get game statistics
   */
  async getGameStats(req, res, next) {
    try {
      const cacheKey = 'games:stats';
      
      const cached = await cacheUtils.get(cacheKey);
      if (cached) {
        return res.json({
          success: true,
          data: cached,
          cached: true,
        });
      }
      
      const [totalGames, activeGames, premiumGames, totalPlays] = await Promise.all([
        Game.count(),
        Game.count({ where: { is_active: true } }),
        Game.count({ where: { is_premium: true } }),
        Game.sum('play_count'),
      ]);
      
      const topGames = await Game.findAll({
        where: { is_active: true },
        order: [['play_count', 'DESC']],
        limit: 10,
        attributes: ['id', 'title', 'type', 'play_count', 'rating'],
      });
      
      const stats = {
        totalGames,
        activeGames,
        premiumGames,
        totalPlays: totalPlays || 0,
        topGames,
      };
      
      await cacheUtils.set(cacheKey, stats, 600);
      
      res.json({
        success: true,
        data: stats,
        cached: false,
      });
    } catch (error) {
      next(error);
    }
  }
}

module.exports = new GameController();