crowd-funder-for-time-pwa/src/services/PlatformServiceFactory.ts

import { PlatformService } from "./PlatformService";
import { WebPlatformService } from "./platforms/WebPlatformService";

/**
 * 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 async getInstance(): Promise<PlatformService> {
    if (PlatformServiceFactory.instance) {
      return PlatformServiceFactory.instance;
    }

    const platform = process.env.VITE_PLATFORM || "web";
    let service: PlatformService;

    switch (platform) {
      case "capacitor": {
        const { CapacitorPlatformService } = await import(
          "./platforms/CapacitorPlatformService"
        );
        service = new CapacitorPlatformService();
        break;
      }
      case "electron": {
        const { ElectronPlatformService } = await import(
          "./platforms/ElectronPlatformService"
        );
        service = new ElectronPlatformService();
        break;
      }
      case "pywebview": {
        const { PyWebViewPlatformService } = await import(
          "./platforms/PyWebViewPlatformService"
        );
        service = new PyWebViewPlatformService();
        break;
      }
      case "web":
      default:
        service = new WebPlatformService();
        break;
    }

    PlatformServiceFactory.instance = service;
    return service;
  }
}