const fs = require('fs');
const path = require('path');

const HOSTER_SETTINGS_DEFAULTS = {
  retries: 3,
  maxSpeedKbs: 0,       // 0 = unlimited
  parallelCount: 2,     // 1-100
  restartBelowKbs: 0,   // 0 = off
  timeIntervalSec: 0,   // delay between jobs
  maxSizeMb: 0          // 0 = unlimited
};

const DEFAULTS = {
  hosters: {
    'doodstream.com': { enabled: true, apiKey: '', username: '', password: '' },
    'voe.sx': { enabled: true, apiKey: '' },
    'vidmoly.me': { enabled: true, authType: 'login', username: '', password: '' },
    'byse.sx': { enabled: true, apiKey: '' }
  },
  hosterSettings: {
    'doodstream.com': { ...HOSTER_SETTINGS_DEFAULTS },
    'voe.sx': { ...HOSTER_SETTINGS_DEFAULTS },
    'vidmoly.me': { ...HOSTER_SETTINGS_DEFAULTS },
    'byse.sx': { ...HOSTER_SETTINGS_DEFAULTS }
  },
  globalSettings: {
    alwaysOnTop: false,
    shutdownAfterFinish: 'nothing', // nothing | sleep | shutdown | restart
    logFilePath: '',
    sessionLog: false,
    resumeQueueOnLaunch: true,
    parallelUploadCount: 0, // 0 = use per-hoster limits only
    scaleParallelUploads: false,
    removeFromQueueOnDone: false,
    globalMaxSpeedKbs: 0, // 0 = unlimited global speed
    pendingQueue: null,
    scramble: {
      active: false,
      prefix: '',
      suffix: '',
      chars: 'both', // 'letters' | 'numbers' | 'both'
      length: 0       // 0 = same as original basename length
    },
    folderMonitor: {
      enabled: false,
      folderPath: '',
      recursive: false,
      filterMode: 'include',  // 'include' | 'exclude'
      extensions: '',          // comma-separated: 'mp4,mkv,avi'
      skipDuplicates: true,
      delaySec: 3,
      autoStart: true
    }
  },
  history: []
};

const MAX_HISTORY = 100;

class ConfigStore {
  constructor(app) {
    const dir = app && app.isPackaged
      ? app.getPath('userData')
      : path.join(__dirname, '..');
    this.filePath = path.join(dir, 'electron-config.json');

    // Migrate config from old location if current doesn't exist
    if (!fs.existsSync(this.filePath) && app && app.isPackaged) {
      this._migrateFromOldPath(app);
    }
  }

  _migrateFromOldPath(app) {
    try {
      const appDataDir = path.dirname(app.getPath('userData'));
      // Check alternate folder names that may have been used
      const candidates = ['multi-hoster-uploader', 'Multi-Hoster-Upload'];
      for (const name of candidates) {
        const oldPath = path.join(appDataDir, name, 'electron-config.json');
        if (oldPath !== this.filePath && fs.existsSync(oldPath)) {
          fs.mkdirSync(path.dirname(this.filePath), { recursive: true });
          fs.copyFileSync(oldPath, this.filePath);
          return;
        }
      }
      // Also check next to the executable (portable mode previous location)
      const exeDir = path.dirname(app.getPath('exe'));
      const portablePath = path.join(exeDir, 'electron-config.json');
      if (portablePath !== this.filePath && fs.existsSync(portablePath)) {
        fs.mkdirSync(path.dirname(this.filePath), { recursive: true });
        fs.copyFileSync(portablePath, this.filePath);
      }
    } catch {}
  }

  _readAndParse(filePath) {
    const raw = fs.readFileSync(filePath, 'utf-8');
    if (!raw || raw.trim().length < 2) return null;
    return JSON.parse(raw);
  }

  load() {
    try {
      let data = null;
      // Try main config
      try { data = this._readAndParse(this.filePath); } catch {}
      // Fallback to backup if main is empty/corrupt
      if (!data) {
        const backupPath = this.filePath + '.bak';
        try { data = this._readAndParse(backupPath); } catch {}
      }
      if (!data) return JSON.parse(JSON.stringify(DEFAULTS));

      // Merge with defaults so new hosters are always present
      const hosters = { ...DEFAULTS.hosters };
      for (const [name, val] of Object.entries(data.hosters || {})) {
        if (hosters[name]) {
          hosters[name] = { ...hosters[name], ...val };
        }
      }
      // Merge hoster settings with defaults
      const hosterSettings = {};
      for (const name of Object.keys(DEFAULTS.hosterSettings)) {
        hosterSettings[name] = {
          ...HOSTER_SETTINGS_DEFAULTS,
          ...(data.hosterSettings && data.hosterSettings[name] || {})
        };
      }
      const savedGlobal = data.globalSettings || {};
      const globalSettings = {
        ...DEFAULTS.globalSettings,
        ...savedGlobal
      };
      // Deep-merge nested objects so new keys are always present
      for (const key of Object.keys(DEFAULTS.globalSettings)) {
        const def = DEFAULTS.globalSettings[key];
        if (def && typeof def === 'object' && !Array.isArray(def)) {
          globalSettings[key] = { ...def, ...(savedGlobal[key] || {}) };
        }
      }
      return { hosters, hosterSettings, globalSettings, history: data.history || [] };
    } catch {
      return JSON.parse(JSON.stringify(DEFAULTS));
    }
  }

  save(config) {
    const current = this.load();
    if (config.hosters) current.hosters = config.hosters;
    if (config.hosterSettings) current.hosterSettings = config.hosterSettings;
    if (config.globalSettings) current.globalSettings = config.globalSettings;
    return this._atomicWrite(JSON.stringify(current, null, 2));
  }

  loadHistory() {
    const config = this.load();
    return config.history || [];
  }

  _atomicWrite(data) {
    return new Promise((resolve, reject) => {
      const tmpPath = this.filePath + '.tmp';
      const backupPath = this.filePath + '.bak';
      fs.writeFile(tmpPath, data, 'utf-8', (err) => {
        if (err) return reject(err);
        try {
          if (fs.existsSync(this.filePath)) {
            const existing = fs.readFileSync(this.filePath, 'utf-8');
            if (existing && existing.trim().length > 2) {
              fs.writeFileSync(backupPath, existing, 'utf-8');
            }
          }
          fs.renameSync(tmpPath, this.filePath);
        } catch (e) { return reject(e); }
        resolve();
      });
    });
  }

  appendHistory(entry) {
    const config = this.load();
    config.history.push(entry);
    if (config.history.length > MAX_HISTORY) {
      config.history = config.history.slice(-MAX_HISTORY);
    }
    return this._atomicWrite(JSON.stringify(config, null, 2));
  }

  clearHistory() {
    const config = this.load();
    config.history = [];
    return this._atomicWrite(JSON.stringify(config, null, 2));
  }
}

module.exports = ConfigStore;