const path = require('path');
const os = require('os');
const fs = require('fs');
const appConfig = require('./app-config');

class LuantiPaths {
  constructor() {
    // Initialize with default, will be updated when app config loads
    this.setDataDirectory(this.getDefaultDataDirectory());
  }

  async initialize() {
    // Load app config and update data directory
    await appConfig.load();
    const configuredDataDir = appConfig.getDataDirectory();
    this.setDataDirectory(configuredDataDir);
    console.log(`Paths initialized with data directory: ${configuredDataDir}`);
  }

  async forceReload() {
    // Force reload the app config and reinitialize paths
    delete require.cache[require.resolve('./app-config')];
    const appConfig = require('./app-config');
    await appConfig.load();
    const configuredDataDir = appConfig.getDataDirectory();
    this.setDataDirectory(configuredDataDir);
    console.log(`Paths force reloaded with data directory: ${configuredDataDir}`);
  }

  getDefaultDataDirectory() {
    const validDirs = this.detectLuantiDataDirectories();
    return validDirs.length > 0 ? validDirs[0].path : path.join(os.homedir(), '.minetest');
  }

  detectLuantiDataDirectories() {
    const homeDir = os.homedir();
    const candidateDirs = [
      // Flatpak installations
      { 
        path: path.join(homeDir, '.var/app/org.luanti.luanti/.minetest'), 
        type: 'Flatpak (org.luanti.luanti)',
        description: 'Luanti installed via Flatpak'
      },
      { 
        path: path.join(homeDir, '.var/app/net.minetest.Minetest/.minetest'), 
        type: 'Flatpak (net.minetest.Minetest)',
        description: 'Minetest installed via Flatpak'
      },
      // Snap installations (they typically use ~/snap/app-name/current/.local/share/minetest)
      { 
        path: path.join(homeDir, 'snap/luanti/current/.local/share/minetest'), 
        type: 'Snap (luanti)',
        description: 'Luanti installed via Snap'
      },
      { 
        path: path.join(homeDir, 'snap/minetest/current/.local/share/minetest'), 
        type: 'Snap (minetest)',
        description: 'Minetest installed via Snap'
      },
      // System package installations
      { 
        path: path.join(homeDir, '.luanti'), 
        type: 'System Package',
        description: 'System-wide Luanti installation'
      },
      { 
        path: path.join(homeDir, '.minetest'), 
        type: 'System Package',
        description: 'System-wide Minetest installation'
      },
      // AppImage or manual installations might use these
      { 
        path: path.join(homeDir, '.local/share/minetest'), 
        type: 'User Installation',
        description: 'User-local installation'
      }
    ];

    // Check which directories exist and contain expected Luanti files
    const validDirs = [];
    for (const candidate of candidateDirs) {
      if (fs.existsSync(candidate.path)) {
        // Check if it looks like a valid Luanti data directory
        const hasConfig = fs.existsSync(path.join(candidate.path, 'minetest.conf'));
        const hasWorlds = fs.existsSync(path.join(candidate.path, 'worlds'));
        const hasDebug = fs.existsSync(path.join(candidate.path, 'debug.txt'));
        
        // Even if some files don't exist, the directory might be valid if it exists
        // (Luanti creates files on first run)
        candidate.confidence = (hasConfig ? 1 : 0) + (hasWorlds ? 1 : 0) + (hasDebug ? 0.5 : 0);
        candidate.exists = true;
        candidate.hasConfig = hasConfig;
        candidate.hasWorlds = hasWorlds;
        candidate.hasDebug = hasDebug;
        
        validDirs.push(candidate);
      }
    }

    // Sort by confidence (directories with more Luanti files first)
    validDirs.sort((a, b) => b.confidence - a.confidence);
    
    return validDirs;
  }

  async getGameDisplayName(gameId) {
    try {
      const games = await this.getInstalledGames();
      const game = games.find(g => g.name === gameId);
      return game ? game.title : gameId;
    } catch (error) {
      console.error('Error getting game display name:', error);
      return gameId;
    }
  }

  setDataDirectory(dataDir) {
    this.minetestDir = path.resolve(dataDir);
    this.worldsDir = path.join(this.minetestDir, 'worlds');
    this.modsDir = path.join(this.minetestDir, 'mods');
    this.gamesDir = path.join(this.minetestDir, 'games');
    this.texturesDir = path.join(this.minetestDir, 'textures');
    this.configFile = path.join(this.minetestDir, 'minetest.conf');
    this.debugFile = path.join(this.minetestDir, 'debug.txt');
  }

  getDataDirectory() {
    return this.minetestDir;
  }

  getWorldPath(worldName) {
    return path.join(this.worldsDir, worldName);
  }

  getWorldConfigPath(worldName) {
    return path.join(this.getWorldPath(worldName), 'world.mt');
  }

  getWorldModsPath(worldName) {
    return path.join(this.getWorldPath(worldName), 'worldmods');
  }

  getModPath(modName) {
    return path.join(this.modsDir, modName);
  }

  getModConfigPath(modName) {
    return path.join(this.getModPath(modName), 'mod.conf');
  }

  getGamePath(gameName) {
    return path.join(this.gamesDir, gameName);
  }

  getGameConfigPath(gameName) {
    return path.join(this.getGamePath(gameName), 'game.conf');
  }

  ensureDirectories() {
    const dirs = [this.minetestDir, this.worldsDir, this.modsDir, this.gamesDir, this.texturesDir];
    dirs.forEach(dir => {
      if (!fs.existsSync(dir)) {
        fs.mkdirSync(dir, { recursive: true });
      }
    });
  }

  isValidWorldName(name) {
    if (!name || typeof name !== 'string') return false;
    return /^[a-zA-Z0-9_-]+$/.test(name) && name.length >= 3 && name.length <= 50;
  }

  isValidModName(name) {
    if (!name || typeof name !== 'string') return false;
    return /^[a-zA-Z0-9_-]+$/.test(name) && name.length <= 50;
  }

  isPathSafe(targetPath) {
    const resolvedPath = path.resolve(targetPath);
    return resolvedPath.startsWith(path.resolve(this.minetestDir));
  }

  mapToActualGameId(directoryName) {
    // Map directory names to the actual game IDs that Luanti recognizes
    // For most cases, the directory name IS the game ID
    const gameIdMap = {
      // Only add mappings here if you're certain they're needed
      // 'minetest_game': 'minetest', // This mapping was incorrect
    };
    
    return gameIdMap[directoryName] || directoryName;
  }

  async getInstalledGames() {
    const games = [];
    // For Flatpak and other sandboxed installations, only look in the configured data directory
    // System installations might also have access to additional directories, but we should
    // primarily focus on the configured data directory to match what Luanti actually sees
    const possibleGameDirs = [
      this.gamesDir // Only the configured games directory
    ];

    for (const gameDir of possibleGameDirs) {
      try {
        const exists = fs.existsSync(gameDir);
        if (!exists) continue;

        const gameDirs = fs.readdirSync(gameDir);
        for (const gameName of gameDirs) {
          const possibleConfigPaths = [
            path.join(gameDir, gameName, 'game.conf'),
            path.join(gameDir, gameName, gameName, 'game.conf') // Handle nested structure
          ];
          
          for (const gameConfigPath of possibleConfigPaths) {
            try {
              if (fs.existsSync(gameConfigPath)) {
                const ConfigParser = require('./config-parser');
                const gameConfig = await ConfigParser.parseGameConfig(gameConfigPath);
                
                // Map directory names to actual game IDs that Luanti recognizes
                const actualGameId = this.mapToActualGameId(gameName);
                
                // Check if we already have this game (avoid duplicates by game ID, title, and resolved path)
                const resolvedPath = fs.realpathSync(path.dirname(gameConfigPath));
                const existingGame = games.find(g => 
                  g.name === actualGameId || 
                  (g.title === (gameConfig.title || gameConfig.name || gameName) && g.resolvedPath === resolvedPath)
                );
                if (!existingGame) {
                  games.push({
                    name: actualGameId, // Use the ID that Luanti recognizes
                    directoryName: gameName, // Keep original for path resolution
                    title: gameConfig.title || gameConfig.name || gameName,
                    description: gameConfig.description || '',
                    author: gameConfig.author || '',
                    path: path.dirname(gameConfigPath),
                    resolvedPath: resolvedPath,
                    isSystemGame: !gameDir.includes(this.minetestDir)
                  });
                }
                break; // Found valid config, stop checking other paths
              }
            } catch (gameError) {
              // Skip invalid games
              console.warn(`Invalid game at ${gameConfigPath}:`, gameError.message);
            }
          }
        }
      } catch (dirError) {
        // Skip directories that can't be read
        continue;
      }
    }

    // Sort games: system games first, then minetest_game first, then alphabetically
    games.sort((a, b) => {
      if (a.isSystemGame !== b.isSystemGame) {
        return a.isSystemGame ? -1 : 1;
      }
      
      // Put minetest_game first as it's the default
      if (a.name === 'minetest_game') return -1;
      if (b.name === 'minetest_game') return 1;
      
      return a.title.localeCompare(b.title);
    });

    return games;
  }
}

module.exports = new LuantiPaths();