const express = require('express');
const db = require('../database');

const router = express.Router();

// Pick a random game with filters and repeat avoidance
router.post('/pick', (req, res) => {
  try {
    const {
      playerCount,
      drawing,
      length,
      familyFriendly,
      sessionId
    } = req.body;

    // Build query for eligible games
    let query = 'SELECT * FROM games WHERE enabled = 1';
    const params = [];

    if (playerCount) {
      const count = parseInt(playerCount);
      query += ' AND min_players <= ? AND max_players >= ?';
      params.push(count, count);
    }

    if (drawing === 'only') {
      query += ' AND game_type = ?';
      params.push('Drawing');
    } else if (drawing === 'exclude') {
      query += ' AND (game_type != ? OR game_type IS NULL)';
      params.push('Drawing');
    }

    if (length) {
      if (length === 'short') {
        query += ' AND (length_minutes <= 15 OR length_minutes IS NULL)';
      } else if (length === 'medium') {
        query += ' AND length_minutes > 15 AND length_minutes <= 25';
      } else if (length === 'long') {
        query += ' AND length_minutes > 25';
      }
    }

    if (familyFriendly !== undefined) {
      query += ' AND family_friendly = ?';
      params.push(familyFriendly ? 1 : 0);
    }

    // Get eligible games
    const stmt = db.prepare(query);
    let eligibleGames = stmt.all(...params);

    if (eligibleGames.length === 0) {
      return res.status(404).json({ 
        error: 'No games match the current filters',
        suggestion: 'Try adjusting your filters or enabling more games'
      });
    }

    // Apply repeat avoidance if session provided
    if (sessionId) {
      const lastGames = db.prepare(`
        SELECT game_id FROM session_games
        WHERE session_id = ?
        ORDER BY played_at DESC
        LIMIT 2
      `).all(sessionId);

      const excludeIds = lastGames.map(g => g.game_id);
      
      if (excludeIds.length > 0) {
        eligibleGames = eligibleGames.filter(game => !excludeIds.includes(game.id));
      }

      if (eligibleGames.length === 0) {
        return res.status(404).json({
          error: 'All eligible games have been played recently',
          suggestion: 'Enable more games or adjust your filters',
          recentlyPlayed: excludeIds
        });
      }
    }

    // Pick random game from eligible pool
    const randomIndex = Math.floor(Math.random() * eligibleGames.length);
    const selectedGame = eligibleGames[randomIndex];

    res.json({
      game: selectedGame,
      poolSize: eligibleGames.length,
      totalEnabled: eligibleGames.length + (sessionId ? 2 : 0) // Approximate
    });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

module.exports = router;