//
//  TransactionObserver.swift
//  PDFReaderPro
//
//  Created by zenghong on 1/8/25.
//

import Foundation
import SwiftUI
import StoreKit


@available(macOS 12.0, *)
@objc final class TransactionObserver: NSObject {
    
    var updates: Task<Void, Never>? = nil
    
//    @Environment(\.displayStoreKitMessage) private var displayStoreMessage
    
    static let shared = TransactionObserver()
    
    override init() {
        super.init()
        updates = newTransactionListenerTask()
    }


    deinit {
        // Cancel the update handling task when you deinitialize the class.
        updates?.cancel()
    }
    
    private func newTransactionListenerTask() -> Task<Void, Never> {
        Task(priority: .background) {
            for await verificationResult in Transaction.updates {
                self.handle(updatedTransaction: verificationResult)
            }
            
//            for await message in StoreKit.Message.messages {
//                if message.reason != .winBackOffer {
                    // Ask the system to display messages now.
//                    try? await displayStoreMessage(message)
//                }
//            }
        }
    }
    
    private func handle(updatedTransaction verificationResult: VerificationResult<StoreKit.Transaction>) {
        guard case .verified(let transaction) = verificationResult else {
            // Ignore unverified transactions.
            return
        }

        print("同步购买信息：\(transaction)")

        if let revocationDate = transaction.revocationDate {
            // Remove access to the product identified by transaction.productID.
            // Transaction.revocationReason provides details about
            // the revoked transaction.
            
        } else if let expirationDate = transaction.expirationDate,
            expirationDate < Date() {
            // Do nothing, this subscription is expired.
            print("订阅过期")
            return
        } else if transaction.isUpgraded {
            // Do nothing, there is an active transaction
            // for a higher level of service.
            return
        } else {
            // Provide access to the product identified by
            // transaction.productID.
            
        }
    }
    
}