// .env.local (개발 환경)
GOOGLE_SERVICE_ACCOUNT_KEY=개발 키 경로

// .env.prod (프로덕션 환경)
GOOGLE_SERVICE_ACCOUNT_KEY=배포 키 경로

// google-play.service.ts
import { google } from 'googleapis';
 
private async initializeGoogleClient() {
  const keyPath = this.configService.get<string>('GOOGLE_SERVICE_ACCOUNT_KEY_PATH');
  const keyData = JSON.parse(fs.readFileSync(keyPath, 'utf8'));
 
  const auth = new google.auth.JWT({
    email: keyData.client_email,
    key: keyData.private_key,
    scopes: ['https://www.googleapis.com/auth/androidpublisher'],
  });
 
  this.androidPublisher = google.androidpublisher({
    version: 'v3',
    auth: auth,
  });
}

// 일반 상품
this.androidPublisher.purchases.products.get()
this.androidPublisher.purchases.products.acknowledge()
this.androidPublisher.purchases.products.consume()
 
// 구독 상품
this.androidPublisher.purchases.subscriptions.get()
this.androidPublisher.purchases.subscriptions.acknowledge()
this.androidPublisher.purchases.subscriptions.cancel()

export class GoogleVerifyPurchaseRequestDto {
  @IsString()
  packageName: string;  // 앱의 패키지명
 
  @IsString()
  productId: string;    // 상품 ID
 
  @IsString()
  purchaseToken: string;  // Google이 발급한 구매 토큰
 
  @IsEnum(PurchaseType)
  purchaseType: PurchaseType;  // 'consumable' | 'subscription'
 
  @IsString()
  @IsOptional()
  orderId?: string;  // 주문 번호
}

async verifyPurchase(dto: GoogleVerifyPurchaseRequestDto): Promise<any> {
  // 1. 중복 구매 체크
  const existingPurchase = await this.checkDuplicatePurchase(dto.purchaseToken);
  if (existingPurchase) {
    return this.buildResponseFromHistory(existingPurchase);
  }
 
  // 2. 상품 타입별 검증
  let verificationData;
  if (dto.purchaseType === PurchaseType.CONSUMABLE) {
    verificationData = await this.verifyProduct(dto);
  } else if (dto.purchaseType === PurchaseType.SUBSCRIPTION) {
    verificationData = await this.verifySubscription(dto);
  }
 
  // 3. 구매 이력 저장
  const purchaseHistory = await this.savePurchaseHistory(dto, verificationData, userId);
 
  // 4. 후처리
  await this.postProcessPurchase(dto, verificationData);
 
  return this.buildResponse(purchaseHistory);
}

private async verifyProduct(dto: GoogleVerifyPurchaseRequestDto) {
  const response = await this.androidPublisher.purchases.products.get({
    packageName: dto.packageName,
    productId: dto.productId,
    token: dto.purchaseToken,
  });
 
  const data = response.data;
 
  // purchaseState 확인: 0 = 구매완료, 1 = 취소됨
  if (data.purchaseState !== 0) {
    throw new BadRequestException('구매가 취소되었거나 유효하지 않습니다');
  }
 
  // Acknowledge 상태 확인: 0 = 미승인, 1 = 승인됨
  if (data.acknowledgementState === 0) {
    await this.acknowledgePurchase(dto);
  }
 
  return data;
}

private async verifySubscription(dto: GoogleVerifyPurchaseRequestDto) {
  const response = await this.androidPublisher.purchases.subscriptions.get({
    packageName: dto.packageName,
    subscriptionId: dto.productId,
    token: dto.purchaseToken,
  });
 
  const data = response.data;
 
  // 만료 시간 체크
  const expiryTime = parseInt(data.expiryTimeMillis);
  if (expiryTime < Date.now()) {
    throw new BadRequestException('구독이 만료되었습니다');
  }
 
  // paymentState 확인: 0 = 대기중, 1 = 결제완료, 2 = 무료체험
  if (data.paymentState === 0) {
    throw new BadRequestException('결제가 아직 처리중입니다');
  }
 
  return data;
}

// 소비성 상품
await this.androidPublisher.purchases.products.acknowledge({
  packageName: dto.packageName,
  productId: dto.productId,
  token: dto.purchaseToken,
});
 
// 구독 상품
await this.androidPublisher.purchases.subscriptions.acknowledge({
  packageName: dto.packageName,
  subscriptionId: dto.productId,
  token: dto.purchaseToken,
});

await this.androidPublisher.purchases.products.consume({
  packageName: dto.packageName,
  productId: dto.productId,
  token: dto.purchaseToken,
});

@Cron('0 */6 * * *')  // 6시간마다
async checkPurchaseStatus() {
  const recentPurchases = await this.purchaseHistoryRepository.find({
    where: {
      createdAt: MoreThan(new Date(Date.now() - 7 * 24 * 60 * 60 * 1000)),
      status: PurchaseStatus.VERIFIED
    }
  });
 
  for (const purchase of recentPurchases) {
    try {
      const verification = await this.verifyProduct({
        packageName: purchase.packageName,
        productId: purchase.productId,
        purchaseToken: purchase.purchaseToken
      });
 
      // purchaseState가 1이면 취소/환불됨
      if (verification.purchaseState === 1) {
        await this.handleRefund(purchase);
      }
    } catch (error) {
      if (error.response?.status === 404) {
        // 구매가 없어짐 = 환불됨
        await this.handleRefund(purchase);
      }
    }
  }
}

// 환불 처리
private async handleRefund(purchase: PurchaseHistory) {
  purchase.status = PurchaseStatus.REFUNDED;
  await this.purchaseHistoryRepository.save(purchase);
 
  await this.revokeItems(purchase.userId, purchase.productId);
 
  this.logger.warn(`환불 처리: userId=${purchase.userId}, productId=${purchase.productId}`);
}