using FsCheck;
using FsCheck.Xunit;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using MiAssessment.Admin.Business.Data;
using MiAssessment.Admin.Business.Entities;
using MiAssessment.Admin.Business.Models.User;
using MiAssessment.Admin.Business.Services;
using Moq;
using Xunit;

namespace MiAssessment.Tests.Admin;

/// <summary>
/// User 属性测试
/// 验证用户服务的正确性属性
/// </summary>
public class UserPropertyTests
{
    private readonly Mock<ILogger<UserBusinessService>> _mockLogger = new();

    #region Property 3: Pagination Correctness

    /// <summary>
    /// Property 3: 分页查询返回的记录数不超过 PageSize
    /// *For any* paginated list query with PageIndex and PageSize parameters, 
    /// the result SHALL contain at most PageSize items.
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_ResultCountNotExceedPageSize(PositiveInt seed, PositiveInt pageSize)
    {
        // Arrange: 创建包含多个用户的数据库
        using var dbContext = CreateDbContext();
        var userCount = (seed.Get % 50) + 1; // 1-50 个用户
        var actualPageSize = Math.Min(pageSize.Get, 100); // PageSize 最大 100
        
        CreateTestUsers(dbContext, userCount, seed.Get);
        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act: 执行分页查询
        var request = new UserQueryRequest 
        { 
            Page = 1, 
            PageSize = actualPageSize 
        };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: 返回的记录数不超过 PageSize
        return result.List.Count <= actualPageSize;
    }

    /// <summary>
    /// Property 3: Total 等于数据库中匹配记录的实际数量
    /// *For any* paginated list query, the Total count SHALL equal 
    /// the actual number of matching records in the database.
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_TotalEqualsActualCount(PositiveInt seed)
    {
        // Arrange: 创建包含多个用户的数据库
        using var dbContext = CreateDbContext();
        var userCount = (seed.Get % 50) + 1; // 1-50 个用户
        
        CreateTestUsers(dbContext, userCount, seed.Get);
        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // 计算数据库中实际的非删除用户数量
        var actualCount = dbContext.Users.Count(u => !u.IsDeleted);

        // Act: 执行分页查询
        var request = new UserQueryRequest { Page = 1, PageSize = 10 };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: Total 等于实际数量
        return result.Total == actualCount;
    }

    /// <summary>
    /// Property 3: 分页查询在不同页码下返回正确的记录数
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_DifferentPagesReturnCorrectCount(PositiveInt seed)
    {
        // Arrange: 创建固定数量的用户
        using var dbContext = CreateDbContext();
        var userCount = 25; // 固定 25 个用户
        var pageSize = 10;
        
        CreateTestUsers(dbContext, userCount, seed.Get);
        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act: 查询第一页
        var request1 = new UserQueryRequest { Page = 1, PageSize = pageSize };
        var result1 = service.GetUserListAsync(request1).GetAwaiter().GetResult();

        // 查询第二页
        var request2 = new UserQueryRequest { Page = 2, PageSize = pageSize };
        var result2 = service.GetUserListAsync(request2).GetAwaiter().GetResult();

        // 查询第三页
        var request3 = new UserQueryRequest { Page = 3, PageSize = pageSize };
        var result3 = service.GetUserListAsync(request3).GetAwaiter().GetResult();

        // Assert: 
        // 第一页应该有 10 条记录
        // 第二页应该有 10 条记录
        // 第三页应该有 5 条记录
        return result1.List.Count == 10 
            && result2.List.Count == 10 
            && result3.List.Count == 5
            && result1.Total == 25
            && result2.Total == 25
            && result3.Total == 25;
    }

    /// <summary>
    /// Property 3: 超出范围的页码返回空列表
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 50)]
    public bool PaginationCorrectness_OutOfRangePageReturnsEmpty(PositiveInt seed)
    {
        // Arrange: 创建少量用户
        using var dbContext = CreateDbContext();
        var userCount = 5;
        
        CreateTestUsers(dbContext, userCount, seed.Get);
        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act: 查询超出范围的页码
        var request = new UserQueryRequest { Page = 100, PageSize = 10 };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: 返回空列表，但 Total 仍然正确
        return result.List.Count == 0 && result.Total == userCount;
    }

    /// <summary>
    /// Property 3: 带筛选条件的分页查询 Total 正确
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_FilteredQueryTotalCorrect(PositiveInt seed)
    {
        // Arrange: 创建不同状态的用户
        using var dbContext = CreateDbContext();
        var activeCount = (seed.Get % 10) + 1;
        var disabledCount = (seed.Get % 5) + 1;
        
        // 创建启用状态的用户
        for (int i = 0; i < activeCount; i++)
        {
            CreateTestUserWithStatus(dbContext, seed.Get + i, 1);
        }
        // 创建禁用状态的用户
        for (int i = 0; i < disabledCount; i++)
        {
            CreateTestUserWithStatus(dbContext, seed.Get + activeCount + i, 0);
        }

        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act: 查询启用状态的用户
        var request = new UserQueryRequest { Page = 1, PageSize = 100, Status = 1 };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: Total 等于启用状态的用户数量
        return result.Total == activeCount;
    }

    /// <summary>
    /// Property 3: 带用户等级筛选的分页查询 Total 正确
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_UserLevelFilterTotalCorrect(PositiveInt seed)
    {
        // Arrange: 创建不同等级的用户
        using var dbContext = CreateDbContext();
        var normalCount = (seed.Get % 10) + 1;
        var partnerCount = (seed.Get % 5) + 1;
        
        // 创建普通用户
        for (int i = 0; i < normalCount; i++)
        {
            CreateTestUserWithLevel(dbContext, seed.Get + i, 1);
        }
        // 创建合伙人
        for (int i = 0; i < partnerCount; i++)
        {
            CreateTestUserWithLevel(dbContext, seed.Get + normalCount + i, 2);
        }

        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act: 查询合伙人
        var request = new UserQueryRequest { Page = 1, PageSize = 100, UserLevel = 2 };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: Total 等于合伙人数量
        return result.Total == partnerCount;
    }

    /// <summary>
    /// Property 3: 软删除的用户不计入 Total
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_DeletedUsersNotInTotal(PositiveInt seed)
    {
        // Arrange: 创建用户，部分软删除
        using var dbContext = CreateDbContext();
        var activeCount = (seed.Get % 10) + 1;
        var deletedCount = (seed.Get % 5) + 1;
        
        // 创建正常用户
        for (int i = 0; i < activeCount; i++)
        {
            CreateTestUser(dbContext, seed.Get + i, false);
        }
        // 创建已删除用户
        for (int i = 0; i < deletedCount; i++)
        {
            CreateTestUser(dbContext, seed.Get + activeCount + i, true);
        }

        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act: 查询用户列表
        var request = new UserQueryRequest { Page = 1, PageSize = 100 };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: Total 只包含未删除的用户
        return result.Total == activeCount;
    }

    /// <summary>
    /// Property 3: TotalPages 计算正确
    /// 
    /// **Validates: Requirements 9.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool PaginationCorrectness_TotalPagesCalculatedCorrectly(PositiveInt seed, PositiveInt pageSize)
    {
        // Arrange
        using var dbContext = CreateDbContext();
        var userCount = (seed.Get % 100) + 1;
        var actualPageSize = Math.Max(1, Math.Min(pageSize.Get, 100));
        
        CreateTestUsers(dbContext, userCount, seed.Get);
        var service = new UserBusinessService(dbContext, _mockLogger.Object);

        // Act
        var request = new UserQueryRequest { Page = 1, PageSize = actualPageSize };
        var result = service.GetUserListAsync(request).GetAwaiter().GetResult();

        // Assert: TotalPages = ceil(Total / PageSize)
        var expectedTotalPages = (int)Math.Ceiling((double)result.Total / actualPageSize);
        return result.TotalPages == expectedTotalPages;
    }

    #endregion

    #region 辅助方法

    /// <summary>
    /// 创建内存数据库上下文
    /// </summary>
    private AdminBusinessDbContext CreateDbContext()
    {
        var options = new DbContextOptionsBuilder<AdminBusinessDbContext>()
            .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString())
            .Options;

        return new AdminBusinessDbContext(options);
    }

    /// <summary>
    /// 创建多个测试用户
    /// </summary>
    private void CreateTestUsers(AdminBusinessDbContext dbContext, int count, int seed)
    {
        for (int i = 0; i < count; i++)
        {
            CreateTestUser(dbContext, seed + i, false);
        }
    }

    /// <summary>
    /// 创建测试用户
    /// </summary>
    private long CreateTestUser(AdminBusinessDbContext dbContext, int seed, bool isDeleted)
    {
        var user = new User
        {
            Uid = $"{seed % 1000000:D6}",
            OpenId = $"openid_{seed}",
            Phone = $"138{seed % 100000000:D8}",
            Nickname = $"User_{seed}",
            Avatar = $"https://example.com/avatar_{seed}.jpg",
            UserLevel = 1,
            Balance = seed % 1000,
            TotalIncome = seed % 5000,
            WithdrawnAmount = seed % 500,
            Status = 1,
            CreateTime = DateTime.Now.AddDays(-seed % 365),
            UpdateTime = DateTime.Now,
            IsDeleted = isDeleted
        };
        dbContext.Users.Add(user);
        dbContext.SaveChanges();
        return user.Id;
    }

    /// <summary>
    /// 创建指定状态的测试用户
    /// </summary>
    private long CreateTestUserWithStatus(AdminBusinessDbContext dbContext, int seed, int status)
    {
        var user = new User
        {
            Uid = $"{seed % 1000000:D6}",
            OpenId = $"openid_{seed}",
            Phone = $"138{seed % 100000000:D8}",
            Nickname = $"User_{seed}",
            Avatar = $"https://example.com/avatar_{seed}.jpg",
            UserLevel = 1,
            Balance = seed % 1000,
            TotalIncome = seed % 5000,
            WithdrawnAmount = seed % 500,
            Status = status,
            CreateTime = DateTime.Now.AddDays(-seed % 365),
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.Users.Add(user);
        dbContext.SaveChanges();
        return user.Id;
    }

    /// <summary>
    /// 创建指定等级的测试用户
    /// </summary>
    private long CreateTestUserWithLevel(AdminBusinessDbContext dbContext, int seed, int userLevel)
    {
        var user = new User
        {
            Uid = $"{seed % 1000000:D6}",
            OpenId = $"openid_{seed}",
            Phone = $"138{seed % 100000000:D8}",
            Nickname = $"User_{seed}",
            Avatar = $"https://example.com/avatar_{seed}.jpg",
            UserLevel = userLevel,
            Balance = seed % 1000,
            TotalIncome = seed % 5000,
            WithdrawnAmount = seed % 500,
            Status = 1,
            CreateTime = DateTime.Now.AddDays(-seed % 365),
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.Users.Add(user);
        dbContext.SaveChanges();
        return user.Id;
    }

    #endregion
}