#import "ViewController.h"
#import <StoreKit/StoreKit.h>

@interface ViewController () <SKPaymentTransactionObserver, SKProductsRequestDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
}
// 添加支付監(jiān)聽
- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [[SKPaymentQueue defaultQueue] addTransactionObserver:self];
}
// 移除支付監(jiān)聽
- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    [[SKPaymentQueue defaultQueue] removeTransactionObserver:self];
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 模擬用戶選擇了6元檔
    [self pay:6];
}

- (void)pay:(NSInteger)money {
    if ([SKPaymentQueue canMakePayments]) {
        // 此處建議為bundleID.金額(假設我的bundleID為com.apple.pay)
        NSSet *productIDSet = [NSSet setWithObject:[NSString stringWithFormat:@"com.apple.pay.%zd", money]];
        SKProductsRequest *request = [[SKProductsRequest alloc] initWithProductIdentifiers:productIDSet];
        request.delegate = self;
        [request start];
    }
}

- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response {
    if([response.products count] == 0) {
        return;
    }
    // 由于上面productID只傳了一個值,此處只需要創(chuàng)建一個訂單
    SKPayment *payment = [SKPayment paymentWithProduct:response.products[0]];
    [[SKPaymentQueue defaultQueue] addPayment:payment];
}

- (void)request:(SKRequest *)request didFailWithError:(NSError *)error {
    // 如果上面的productID不存在,就會報錯
    NSLog(@"error:%@", error);
}

- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transaction {
    if (transaction.count == 0) {
        return;
    }
    for (SKPaymentTransaction *paymentTransaction in transaction) {
        switch (paymentTransaction.transactionState) {
            case SKPaymentTransactionStatePurchased: {
                // 為了安全,支付完成需要驗證一下
                NSURL *receiptURL = [[NSBundle mainBundle] appStoreReceiptURL];
                NSData *receiptData = [NSData dataWithContentsOfURL:receiptURL];
                NSString *receipt_data = [receiptData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithLineFeed];
                NSDictionary *param = @{@"receipt-data": receipt_data};
                // 獲取到receipt-data,需要拿他去請求蘋果服務器
                [self completeTransaction:paymentTransaction param:param];
            }   break;
            case SKPaymentTransactionStateFailed:
                // 一定不要忘記完成訂單,不然進到這個頁面就會執(zhí)行該監(jiān)聽方法:(paymentQueue:updatedTransactions:)而且無法購買相同金額的的產品
                [[SKPaymentQueue defaultQueue] finishTransaction:paymentTransaction];
                break;
            default:
                break;
        }
    }
}
// 該步驟驗證需要在服務器操作,測試階段可以先在客戶端體驗一下
- (void)completeTransaction:(SKPaymentTransaction *)transaction param:(NSDictionary *)param {
    NSData *data = [NSJSONSerialization dataWithJSONObject:param options:(NSJSONWritingPrettyPrinted) error:nil];
    // 正式環(huán)境應為(https://buy.itunes.apple.com/verifyReceipt)
    NSURL *url = [NSURL URLWithString:@"https://sandbox.itunes.apple.com/verifyReceipt"];
    NSMutableURLRequest *connectionRequest = [NSMutableURLRequest requestWithURL:url];
    [connectionRequest setHTTPMethod:@"POST"];
    [connectionRequest setCachePolicy:NSURLRequestUseProtocolCachePolicy];
    [connectionRequest setHTTPBody:data];
    
    NSError *error;
    NSData *responseData = [NSURLConnection sendSynchronousRequest:connectionRequest returningResponse:nil error:&error];
    if (error) {
        NSLog(@"error:%@",error);
        return;
    }
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingAllowFragments error:nil];
    NSLog(@"success:%@",dic);
    if ([dic[@"status"] integerValue] == 0) {
        // 如果status值為0說明支付成功,需要手動調用此方法;如果status為21007說明接口使用錯誤,此時為沙盒環(huán)境,需要用sandbox接口
        [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
    }
}

@end