const fs = require('fs').promises;
const fsSync = require('fs');
const path = require('path');
const os = require('os');

class AppConfig {
  constructor() {
    this.configDir = path.join(os.homedir(), '.luhost');
    this.configFile = path.join(this.configDir, 'config.json');
    this.defaultConfig = {
      dataDirectory: this.getDefaultDataDirectory(),
      serverPort: 3000,
      debugMode: false
    };
    this.config = null;
  }

  getDefaultDataDirectory() {
    const homeDir = os.homedir();
    const possibleDirs = [
      path.join(homeDir, '.luanti'),
      path.join(homeDir, '.minetest')
    ];

    // Use the first one that exists, or default to .minetest
    for (const dir of possibleDirs) {
      if (fsSync.existsSync(dir)) {
        return dir;
      }
    }
    
    return path.join(homeDir, '.minetest');
  }

  async load() {
    try {
      // Ensure config directory exists
      if (!fsSync.existsSync(this.configDir)) {
        await fs.mkdir(this.configDir, { recursive: true });
      }

      // Try to read existing config
      try {
        const configData = await fs.readFile(this.configFile, 'utf8');
        this.config = { ...this.defaultConfig, ...JSON.parse(configData) };
      } catch (error) {
        if (error.code === 'ENOENT') {
          // Config file doesn't exist, create it with defaults
          this.config = { ...this.defaultConfig };
          await this.save();
        } else {
          throw error;
        }
      }

      return this.config;
    } catch (error) {
      console.error('Failed to load app config:', error);
      // Fall back to defaults if config loading fails
      this.config = { ...this.defaultConfig };
      return this.config;
    }
  }

  async save() {
    try {
      if (!fsSync.existsSync(this.configDir)) {
        await fs.mkdir(this.configDir, { recursive: true });
      }
      
      await fs.writeFile(this.configFile, JSON.stringify(this.config, null, 2), 'utf8');
    } catch (error) {
      console.error('Failed to save app config:', error);
      throw error;
    }
  }

  get(key) {
    return this.config ? this.config[key] : this.defaultConfig[key];
  }

  set(key, value) {
    if (!this.config) {
      this.config = { ...this.defaultConfig };
    }
    this.config[key] = value;
  }

  async update(updates) {
    if (!this.config) {
      this.config = { ...this.defaultConfig };
    }
    
    Object.assign(this.config, updates);
    await this.save();
  }

  getDataDirectory() {
    return this.get('dataDirectory');
  }

  async setDataDirectory(dataDir) {
    const resolvedPath = path.resolve(dataDir);
    
    // Validate that the directory exists or can be created
    try {
      await fs.access(resolvedPath);
    } catch (error) {
      if (error.code === 'ENOENT') {
        // Try to create the directory
        try {
          await fs.mkdir(resolvedPath, { recursive: true });
        } catch (createError) {
          throw new Error(`Cannot create data directory: ${createError.message}`);
        }
      } else {
        throw new Error(`Cannot access data directory: ${error.message}`);
      }
    }

    this.set('dataDirectory', resolvedPath);
    await this.save();
    return resolvedPath;
  }
}

module.exports = new AppConfig();