using FsCheck;
using FsCheck.Xunit;
using FreeSql;
using LiveForum.IService.Others;
using LiveForum.Model;
using LiveForum.Service.Cdk;
using Moq;
using Xunit;

namespace LiveForum.Tests
{
    /// <summary>
    /// CDK服务属性测试
    /// Feature: cdk-activation
    /// </summary>
    public class CdkServicePropertyTests
    {
        /// <summary>
        /// Property 2: CDK 激活成功更新状态
        /// *For any* valid and unused CDK, when a user activates it, the system SHALL mark the CDK as used, 
        /// record the user ID, and update the user's IsCdkActivated to true.
        /// **Validates: Requirements 2.3, 2.5**
        /// </summary>
        [Property(MaxTest = 100)]
        public bool CdkActivation_ShouldUpdateBothCdkAndUserStatus(PositiveInt userIdArb, NonEmptyString cdkCodeArb)
        {
            // Arrange
            var userId = (long)userIdArb.Get;
            var cdkCode = cdkCodeArb.Get;

            // Skip whitespace-only codes as they are handled by input validation, not CDK lookup
            if (string.IsNullOrWhiteSpace(cdkCode))
            {
                return true; // Trivially true for invalid input - tested by Property 4
            }

            var cdk = new T_CDKs
            {
                Id = 1,
                Code = cdkCode,
                Status = 0, // Unused
                UsedByUserId = null,
                UsedAt = null,
                CreatedAt = DateTime.Now
            };

            var user = new T_Users
            {
                Id = userId,
                NickName = "TestUser",
                IsCdkActivated = false,
                CdkActivatedAt = null
            };

            T_CDKs? updatedCdk = null;
            T_Users? updatedUser = null;

            // Mock CDK repository
            var cdkRepoMock = new Mock<IBaseRepository<T_CDKs>>();
            var cdkSelectMock = new Mock<ISelect<T_CDKs>>();
            cdkSelectMock.Setup(s => s.Where(It.IsAny<System.Linq.Expressions.Expression<Func<T_CDKs, bool>>>()))
                .Returns(cdkSelectMock.Object);
            cdkSelectMock.Setup(s => s.FirstAsync(default))
                .ReturnsAsync(cdk);
            cdkRepoMock.Setup(r => r.Select).Returns(cdkSelectMock.Object);
            cdkRepoMock.Setup(r => r.UpdateAsync(It.IsAny<T_CDKs>(), default))
                .Callback<T_CDKs, CancellationToken>((c, _) => updatedCdk = c)
                .ReturnsAsync(1);

            // Mock User repository
            var userRepoMock = new Mock<IBaseRepository<T_Users>>();
            var userSelectMock = new Mock<ISelect<T_Users>>();
            userSelectMock.Setup(s => s.Where(It.IsAny<System.Linq.Expressions.Expression<Func<T_Users, bool>>>()))
                .Returns(userSelectMock.Object);
            userSelectMock.Setup(s => s.FirstAsync(default))
                .ReturnsAsync(user);
            userRepoMock.Setup(r => r.Select).Returns(userSelectMock.Object);
            userRepoMock.Setup(r => r.UpdateAsync(It.IsAny<T_Users>(), default))
                .Callback<T_Users, CancellationToken>((u, _) => updatedUser = u)
                .ReturnsAsync(1);

            // Mock System Settings Service
            var settingsServiceMock = new Mock<ISystemSettingsService>();
            settingsServiceMock.Setup(s => s.GetSettingAsync(CdkService.CDK_ENABLED_KEY))
                .ReturnsAsync("true");

            var service = new CdkService(cdkRepoMock.Object, userRepoMock.Object, settingsServiceMock.Object);

            // Act
            var result = service.ActivateCdkAsync(userId, cdkCode).GetAwaiter().GetResult();

            // Assert - Property: After successful activation, both CDK and User should be updated
            var cdkUpdated = updatedCdk != null && updatedCdk.Status == 1 && updatedCdk.UsedByUserId == userId && updatedCdk.UsedAt != null;
            var userUpdated = updatedUser != null && updatedUser.IsCdkActivated == true && updatedUser.CdkActivatedAt != null;
            var successMessage = result == "CDK 激活成功";

            return cdkUpdated && userUpdated && successMessage;
        }

        /// <summary>
        /// Property 3: CDK 唯一性验证
        /// *For any* CDK that has been used, attempting to activate it again SHALL return an error 
        /// indicating the CDK has already been activated.
        /// **Validates: Requirements 2.2, 3.2**
        /// </summary>
        [Property(MaxTest = 100)]
        public bool UsedCdk_ShouldReturnAlreadyActivatedError(PositiveInt userIdArb, NonEmptyString cdkCodeArb)
        {
            // Arrange
            var userId = (long)userIdArb.Get;
            var cdkCode = cdkCodeArb.Get;

            // Skip whitespace-only codes as they are handled by input validation, not CDK lookup
            if (string.IsNullOrWhiteSpace(cdkCode))
            {
                return true; // Trivially true for invalid input - tested by Property 4
            }

            // Create a CDK that is already used (Status = 1)
            var usedCdk = new T_CDKs
            {
                Id = 1,
                Code = cdkCode,
                Status = 1, // Already used
                UsedByUserId = 999, // Used by another user
                UsedAt = DateTime.Now.AddDays(-1),
                CreatedAt = DateTime.Now.AddDays(-7)
            };

            var user = new T_Users
            {
                Id = userId,
                NickName = "TestUser",
                IsCdkActivated = false,
                CdkActivatedAt = null
            };

            T_CDKs? updatedCdk = null;
            T_Users? updatedUser = null;

            // Mock CDK repository
            var cdkRepoMock = new Mock<IBaseRepository<T_CDKs>>();
            var cdkSelectMock = new Mock<ISelect<T_CDKs>>();
            cdkSelectMock.Setup(s => s.Where(It.IsAny<System.Linq.Expressions.Expression<Func<T_CDKs, bool>>>()))
                .Returns(cdkSelectMock.Object);
            cdkSelectMock.Setup(s => s.FirstAsync(default))
                .ReturnsAsync(usedCdk);
            cdkRepoMock.Setup(r => r.Select).Returns(cdkSelectMock.Object);
            cdkRepoMock.Setup(r => r.UpdateAsync(It.IsAny<T_CDKs>(), default))
                .Callback<T_CDKs, CancellationToken>((c, _) => updatedCdk = c)
                .ReturnsAsync(1);

            // Mock User repository
            var userRepoMock = new Mock<IBaseRepository<T_Users>>();
            var userSelectMock = new Mock<ISelect<T_Users>>();
            userSelectMock.Setup(s => s.Where(It.IsAny<System.Linq.Expressions.Expression<Func<T_Users, bool>>>()))
                .Returns(userSelectMock.Object);
            userSelectMock.Setup(s => s.FirstAsync(default))
                .ReturnsAsync(user);
            userRepoMock.Setup(r => r.Select).Returns(userSelectMock.Object);
            userRepoMock.Setup(r => r.UpdateAsync(It.IsAny<T_Users>(), default))
                .Callback<T_Users, CancellationToken>((u, _) => updatedUser = u)
                .ReturnsAsync(1);

            // Mock System Settings Service
            var settingsServiceMock = new Mock<ISystemSettingsService>();
            settingsServiceMock.Setup(s => s.GetSettingAsync(CdkService.CDK_ENABLED_KEY))
                .ReturnsAsync("true");

            var service = new CdkService(cdkRepoMock.Object, userRepoMock.Object, settingsServiceMock.Object);

            // Act
            var result = service.ActivateCdkAsync(userId, cdkCode).GetAwaiter().GetResult();

            // Assert - Property: Used CDK should return error and NOT update anything
            var errorMessageCorrect = result == "该 CDK 已被激活";
            var cdkNotUpdated = updatedCdk == null; // CDK should not be updated
            var userNotUpdated = updatedUser == null; // User should not be updated

            return errorMessageCorrect && cdkNotUpdated && userNotUpdated;
        }
    }
}