import { PlatformService } from './PlatformService'
import { WebPlatformService } from './platforms/WebPlatformService'
import { CapacitorPlatformService } from './platforms/CapacitorPlatformService'
import { ElectronPlatformService } from './platforms/ElectronPlatformService'
import { PyWebViewPlatformService } from './platforms/PyWebViewPlatformService'

/**
 * Factory class for creating platform-specific service implementations.
 * Implements the Singleton pattern to ensure only one instance of PlatformService exists.
 *
 * The factory determines which platform implementation to use based on the VITE_PLATFORM
 * environment variable. Supported platforms are:
 * - capacitor: Mobile platform using Capacitor
 * - electron: Desktop platform using Electron
 * - pywebview: Python WebView implementation
 * - web: Default web platform (fallback)
 *
 * @example
 * ```typescript
 * const platformService = PlatformServiceFactory.getInstance();
 * await platformService.takePicture();
 * ```
 */
export class PlatformServiceFactory {
  private static instance: PlatformService | null = null

  /**
   * Gets or creates the singleton instance of PlatformService.
   * Creates the appropriate platform-specific implementation based on environment.
   *
   * @returns {PlatformService} The singleton instance of PlatformService
   */
  public static getInstance(): PlatformService {
    if (PlatformServiceFactory.instance) {
      return PlatformServiceFactory.instance
    }

    const platform = process.env.VITE_PLATFORM || 'web'

    switch (platform) {
      case 'capacitor':
        PlatformServiceFactory.instance = new CapacitorPlatformService()
        break
      case 'electron':
        PlatformServiceFactory.instance = new ElectronPlatformService()
        break
      case 'pywebview':
        PlatformServiceFactory.instance = new PyWebViewPlatformService()
        break
      case 'web':
      default:
        PlatformServiceFactory.instance = new WebPlatformService()
        break
    }

    return PlatformServiceFactory.instance
  }
}