//
//  IAPManager.swift
//  QuickLocation
//
//  Created by 八条 on 2026/7/3.
//

import StoreKit
import RxSwift

class IAPManager: NSObject {
    static let shared = IAPManager()
    private let disposeBag = DisposeBag()

    private var currentGoodsId: String = ""
    private var purchaseCompletion: ((Bool, String?) -> Void)?

    func startObserving() {
        SKPaymentQueue.default().add(self)
    }

    func purchase(goodsId: String, completion: @escaping (Bool, String?) -> Void) {
        currentGoodsId = goodsId
        purchaseCompletion = completion
        let request = SKProductsRequest(productIdentifiers: [goodsId])
        request.delegate = self
        request.start()
    }
}

// MARK: - SKProductsRequestDelegate
extension IAPManager: SKProductsRequestDelegate {
    func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
        guard let product = response.products.first else {
            purchaseCompletion?(false, "商品不可用")
            return
        }
        SKPaymentQueue.default().add(SKPayment(product: product))
    }
}

// MARK: - SKPaymentTransactionObserver
extension IAPManager: SKPaymentTransactionObserver {
    func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
        for tx in transactions {
            switch tx.transactionState {
            case .purchased:
                verifyReceipt(transaction: tx)
            case .failed:
                queue.finishTransaction(tx)
                let msg = tx.error?.localizedDescription ?? "支付失败"
                purchaseCompletion?(false, msg)
            default:
                break
            }
        }
    }

    private func verifyReceipt(transaction: SKPaymentTransaction) {
        guard let receiptURL = Bundle.main.appStoreReceiptURL,
              let receiptData = try? Data(contentsOf: receiptURL) else {
            SKPaymentQueue.default().finishTransaction(transaction)
            purchaseCompletion?(false, "获取凭证失败")
            return
        }
        let receipt = receiptData.base64EncodedString()
        let txId = transaction.transactionIdentifier ?? ""

        OrderService.appleNotify(
            receipt: receipt,
            productId: currentGoodsId,
            transactionId: txId
        ).subscribe(onNext: { [weak self] _ in
            SKPaymentQueue.default().finishTransaction(transaction)
            self?.purchaseCompletion?(true, nil)
        }, onError: { [weak self] error in
            SKPaymentQueue.default().finishTransaction(transaction)
            self?.purchaseCompletion?(false, error.localizedDescription)
        }).disposed(by: disposeBag)
    }
}