vending-machine/backend/tests/VendingMachine.Tests/MembershipPropertyTests.cs

using FsCheck;
using FsCheck.Xunit;
using VendingMachine.Application.Services;

namespace VendingMachine.Tests;

/// <summary>
/// 会员与支付模块属性测试
/// </summary>
public class MembershipPropertyTests
{
    // Feature: vending-machine-app, Property 7: 会员页按钮状态取决于会员类型
    // 对于任意用户的会员类型（none/monthly/subscription），会员页按钮应遵循以下规则：
    // 无会员时显示开通按钮；已购单月会员时隐藏单月按钮仅显示订阅按钮；已购订阅会员时按钮置灰不可点击。
    // **Validates: Requirements 4.3, 4.7, 4.8**
    [Property(MaxTest = 100)]
    public bool MembershipButtonState_None_ShowsBothButtons(int seed)
    {
        var state = IMembershipService.GetButtonState("none");
        return state.ShowMonthlyButton
            && state.ShowSubscriptionButton
            && state.MonthlyButtonEnabled
            && state.SubscriptionButtonEnabled;
    }

    [Property(MaxTest = 100)]
    public bool MembershipButtonState_Monthly_HidesMonthlyButton(int seed)
    {
        var state = IMembershipService.GetButtonState("monthly");
        return !state.ShowMonthlyButton
            && state.ShowSubscriptionButton
            && !state.MonthlyButtonEnabled
            && state.SubscriptionButtonEnabled;
    }

    [Property(MaxTest = 100)]
    public bool MembershipButtonState_Subscription_DisablesAllButtons(int seed)
    {
        var state = IMembershipService.GetButtonState("subscription");
        return !state.MonthlyButtonEnabled
            && !state.SubscriptionButtonEnabled
            && state.SubscriptionButtonText == "已购买订阅会员";
    }

    // Feature: vending-machine-app, Property 8: 平台与支付方式映射
    // 对于任意设备平台，Android 应调用 Google Pay，iOS 应调用 Apple Pay。
    // **Validates: Requirements 4.2**
    [Property(MaxTest = 100)]
    public bool PlatformPaymentMethod_Android_MapsToGooglePay(int seed)
    {
        return IMembershipService.GetPaymentMethod("android") == "Google Pay";
    }

    [Property(MaxTest = 100)]
    public bool PlatformPaymentMethod_iOS_MapsToApplePay(int seed)
    {
        return IMembershipService.GetPaymentMethod("ios") == "Apple Pay";
    }

    // Feature: vending-machine-app, Property 9: 积分保留与清空规则
    // 对于任意会员到期的用户，如果当前时间距会员到期不超过3个月则积分保留，超过3个月则积分清空为0。
    // **Validates: Requirements 4.4, 4.5**
    [Property(MaxTest = 100)]
    public bool PointsRetention_WhenExpiredWithin3Months_ShouldRetain(PositiveInt daysExpired)
    {
        // 限制在1-89天内（不超过3个月≈90天）
        var days = (daysExpired.Get % 89) + 1;
        var expireDate = DateTime.UtcNow.AddDays(-days);
        var now = DateTime.UtcNow;

        // 到期不超过3个月，积分应保留（不清空）
        return !IMembershipService.ShouldClearPoints(expireDate, now);
    }

    [Property(MaxTest = 100)]
    public bool PointsClear_WhenExpiredOver3Months_ShouldClear(PositiveInt extraDays)
    {
        // 到期超过3个月（91天+额外天数）
        var days = 91 + (extraDays.Get % 275);
        var expireDate = DateTime.UtcNow.AddDays(-days);
        var now = DateTime.UtcNow;

        // 到期超过3个月，积分应被清空
        return IMembershipService.ShouldClearPoints(expireDate, now);
    }

    [Property(MaxTest = 100)]
    public bool PointsNotCleared_WhenMembershipNotExpired(PositiveInt daysUntilExpire)
    {
        // 会员未到期（未来1-365天）
        var days = (daysUntilExpire.Get % 365) + 1;
        var expireDate = DateTime.UtcNow.AddDays(days);
        var now = DateTime.UtcNow;

        // 会员未到期，积分不应被清空
        return !IMembershipService.ShouldClearPoints(expireDate, now);
    }

    // Feature: vending-machine-app, Property 17: 支付错误处理
    // 对于任意支付错误（无效凭证），App 应拒绝操作且用户状态保持不变。
    // **Validates: Requirements 8.4**
    [Property(MaxTest = 100)]
    public bool PaymentError_EmptyReceipt_ShouldReject(NonEmptyString platform)
    {
        // 空凭证应被拒绝
        return !IMembershipService.ValidateReceipt("", platform.Get);
    }

    [Property(MaxTest = 100)]
    public bool PaymentError_EmptyPlatform_ShouldReject(NonEmptyString receipt)
    {
        // 空平台应被拒绝
        return !IMembershipService.ValidateReceipt(receipt.Get, "");
    }

    [Property(MaxTest = 100)]
    public bool PaymentError_InvalidPlatform_ShouldReject(NonEmptyString receipt, NonEmptyString platform)
    {
        var p = platform.Get.ToLowerInvariant();
        // 排除有效平台
        if (p == "android" || p == "ios")
            return true; // 跳过有效平台

        return !IMembershipService.ValidateReceipt(receipt.Get, platform.Get);
    }

    [Property(MaxTest = 100)]
    public bool PaymentValidation_ValidInput_ShouldAccept(NonEmptyString receipt, bool useAndroid)
    {
        var platform = useAndroid ? "android" : "ios";
        var receiptStr = receipt.Get;
        // 跳过纯空白字符串（ValidateReceipt 正确地拒绝空白凭证）
        if (string.IsNullOrWhiteSpace(receiptStr))
            return true;
        return IMembershipService.ValidateReceipt(receiptStr, platform);
    }
}