import { Capacitor } from "@capacitor/core";
import { QRScannerService } from "./types";
import { CapacitorQRScanner } from "./CapacitorQRScanner";
import { WebDialogQRScanner } from "./WebDialogQRScanner";
import { logger } from "@/utils/logger";

/**
 * Factory class for creating QR scanner instances based on platform
 */
export class QRScannerFactory {
  private static instance: QRScannerService | null = null;

  private static isNativePlatform(): boolean {
    const capacitorNative = Capacitor.isNativePlatform();
    const isMobile = __IS_MOBILE__;
    const platform = Capacitor.getPlatform();
    
    logger.log('Platform detection:', {
      capacitorNative,
      isMobile,
      platform,
      userAgent: navigator.userAgent
    });

    // Force native scanner on Android/iOS
    if (platform === 'android' || platform === 'ios') {
      return true;
    }

    return capacitorNative || isMobile;
  }

  /**
   * Get a QR scanner instance appropriate for the current platform
   */
  static getInstance(): QRScannerService {
    if (!this.instance) {
      const isNative = this.isNativePlatform();
      logger.log(`Creating QR scanner for platform: ${isNative ? 'native' : 'web'}`);
      
      if (isNative) {
        logger.log('Using native MLKit scanner');
        this.instance = new CapacitorQRScanner();
      } else if (__USE_QR_READER__) {
        logger.log('Using web QR scanner');
        this.instance = new WebDialogQRScanner();
      } else {
        throw new Error("No QR scanner implementation available for this platform");
      }
    }
    return this.instance!; // We know it's not null here
  }

  /**
   * Clean up the current scanner instance
   */
  static async cleanup(): Promise<void> {
    if (this.instance) {
      await this.instance.cleanup();
      this.instance = null;
    }
  }
}