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;
using MiAssessment.Admin.Business.Models.Assessment;
using MiAssessment.Admin.Business.Models.Common;
using MiAssessment.Admin.Business.Services;
using Moq;
using Xunit;

namespace MiAssessment.Tests.Admin;

/// <summary>
/// Category 属性测试
/// 验证报告分类服务的正确性属性
/// </summary>
public class CategoryPropertyTests
{
    private readonly Mock<ILogger<AssessmentService>> _mockLogger = new();

    #region Property 9: Tree Structure Correctness

    /// <summary>
    /// Property 9: 树形结构中所有子分类的 ParentId 必须引用存在的父分类
    /// *For any* category tree query, all child categories SHALL have their ParentId 
    /// referencing an existing parent category, and the tree structure SHALL correctly 
    /// represent the parent-child relationships.
    /// 
    /// **Validates: Requirements 6.1, 6.5**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool TreeStructure_AllChildrenHaveValidParentId(PositiveInt seed)
    {
        // Arrange: 创建包含多级分类的数据库
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        // 创建顶级分类
        var rootCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Root Category {seed.Get}",
            Code = $"ROOT_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(rootCategory);
        dbContext.SaveChanges();

        // 创建子分类
        var childCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = rootCategory.Id,
            Name = $"Child Category {seed.Get}",
            Code = $"CHILD_{seed.Get}",
            CategoryType = 2,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(childCategory);
        dbContext.SaveChanges();

        // 创建孙子分类
        var grandchildCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = childCategory.Id,
            Name = $"Grandchild Category {seed.Get}",
            Code = $"GRANDCHILD_{seed.Get}",
            CategoryType = 3,
            ScoreRule = 2,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(grandchildCategory);
        dbContext.SaveChanges();

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

        // Act: 获取分类树
        var tree = service.GetCategoryTreeAsync(assessmentTypeId).GetAwaiter().GetResult();

        // Assert: 验证树形结构正确性
        // 1. 应该有一个顶级分类
        if (tree.Count != 1) return false;

        var root = tree[0];
        if (root.ParentId != 0) return false;
        if (root.Id != rootCategory.Id) return false;

        // 2. 顶级分类应该有一个子分类
        if (root.Children.Count != 1) return false;

        var child = root.Children[0];
        if (child.ParentId != root.Id) return false;
        if (child.Id != childCategory.Id) return false;

        // 3. 子分类应该有一个孙子分类
        if (child.Children.Count != 1) return false;

        var grandchild = child.Children[0];
        if (grandchild.ParentId != child.Id) return false;
        if (grandchild.Id != grandchildCategory.Id) return false;

        return true;
    }

    /// <summary>
    /// Property 9: 创建子分类时 ParentId 必须引用存在的父分类
    /// 
    /// **Validates: Requirements 6.5**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool TreeStructure_CreateChildWithInvalidParentId_ShouldFail(PositiveInt seed)
    {
        // Arrange
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);
        var service = new AssessmentService(dbContext, _mockLogger.Object);

        // Act: 尝试创建引用不存在父分类的子分类
        var request = new CreateCategoryRequest
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 999999, // 不存在的父分类ID
            Name = $"Invalid Child {seed.Get}",
            Code = $"INVALID_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1
        };

        // Assert: 应该抛出 BusinessException
        try
        {
            service.CreateCategoryAsync(request).GetAwaiter().GetResult();
            return false; // 应该抛出异常
        }
        catch (BusinessException ex)
        {
            return ex.Code == ErrorCodes.CategoryNotFound;
        }
    }

    /// <summary>
    /// Property 9: 创建子分类时 ParentId 引用存在的父分类应该成功
    /// 
    /// **Validates: Requirements 6.5**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool TreeStructure_CreateChildWithValidParentId_ShouldSucceed(PositiveInt seed)
    {
        // Arrange
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        // 创建父分类
        var parentCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Parent {seed.Get}",
            Code = $"PARENT_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(parentCategory);
        dbContext.SaveChanges();

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

        // Act: 创建引用存在父分类的子分类
        var request = new CreateCategoryRequest
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = parentCategory.Id,
            Name = $"Child {seed.Get}",
            Code = $"CHILD_{seed.Get}",
            CategoryType = 2,
            ScoreRule = 1,
            Sort = 1
        };

        try
        {
            var childId = service.CreateCategoryAsync(request).GetAwaiter().GetResult();
            var child = dbContext.ReportCategories.FirstOrDefault(c => c.Id == childId);
            return child != null && child.ParentId == parentCategory.Id;
        }
        catch (BusinessException)
        {
            return false;
        }
    }

    /// <summary>
    /// Property 9: 树形结构应该正确表示多级嵌套关系
    /// 
    /// **Validates: Requirements 6.1, 6.5**
    /// </summary>
    [Property(MaxTest = 50)]
    public bool TreeStructure_MultiLevelNesting_ShouldBeCorrect(PositiveInt seed, PositiveInt depth)
    {
        // 限制深度为1-5层
        var actualDepth = (depth.Get % 5) + 1;

        // Arrange
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        // 创建多级分类
        var categoryIds = new List<long>();
        long parentId = 0;

        for (int i = 0; i < actualDepth; i++)
        {
            var category = new ReportCategory
            {
                AssessmentTypeId = assessmentTypeId,
                ParentId = parentId,
                Name = $"Level {i} Category {seed.Get}",
                Code = $"L{i}_{seed.Get}",
                CategoryType = (i % 8) + 1,
                ScoreRule = (i % 2) + 1,
                Sort = i,
                CreateTime = DateTime.Now,
                UpdateTime = DateTime.Now,
                IsDeleted = false
            };
            dbContext.ReportCategories.Add(category);
            dbContext.SaveChanges();
            categoryIds.Add(category.Id);
            parentId = category.Id;
        }

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

        // Act: 获取分类树
        var tree = service.GetCategoryTreeAsync(assessmentTypeId).GetAwaiter().GetResult();

        // Assert: 验证树形结构深度正确
        var currentLevel = tree;
        for (int i = 0; i < actualDepth; i++)
        {
            if (currentLevel.Count != 1) return false;
            var node = currentLevel[0];
            if (node.Id != categoryIds[i]) return false;

            if (i < actualDepth - 1)
            {
                currentLevel = node.Children;
            }
            else
            {
                // 最后一级应该没有子分类
                if (node.Children.Count != 0) return false;
            }
        }

        return true;
    }

    /// <summary>
    /// Property 9: 软删除的分类不应出现在树形结构中
    /// 
    /// **Validates: Requirements 6.1**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool TreeStructure_DeletedCategoriesNotInTree(PositiveInt seed)
    {
        // Arrange
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        // 创建两个分类，一个正常，一个已删除
        var normalCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Normal {seed.Get}",
            Code = $"NORMAL_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };

        var deletedCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Deleted {seed.Get}",
            Code = $"DELETED_{seed.Get}",
            CategoryType = 2,
            ScoreRule = 1,
            Sort = 2,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = true // 已软删除
        };

        dbContext.ReportCategories.AddRange(normalCategory, deletedCategory);
        dbContext.SaveChanges();

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

        // Act: 获取分类树
        var tree = service.GetCategoryTreeAsync(assessmentTypeId).GetAwaiter().GetResult();

        // Assert: 只应该有一个分类（正常的那个）
        return tree.Count == 1 && tree[0].Id == normalCategory.Id;
    }

    #endregion

    #region Property 18: Category Deletion Constraint

    /// <summary>
    /// Property 18: 有子分类的分类不能删除
    /// *For any* category with child categories, attempting to delete the category 
    /// SHALL return an error and the category SHALL remain unchanged.
    /// 
    /// **Validates: Requirements 6.6**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool DeletionConstraint_CategoryWithChildren_ShouldFailToDelete(PositiveInt seed)
    {
        // Arrange: 创建父子分类
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        var parentCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Parent {seed.Get}",
            Code = $"PARENT_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(parentCategory);
        dbContext.SaveChanges();

        var childCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = parentCategory.Id,
            Name = $"Child {seed.Get}",
            Code = $"CHILD_{seed.Get}",
            CategoryType = 2,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(childCategory);
        dbContext.SaveChanges();

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

        // Act: 尝试删除有子分类的父分类
        try
        {
            service.DeleteCategoryAsync(parentCategory.Id).GetAwaiter().GetResult();
            return false; // 应该抛出异常
        }
        catch (BusinessException ex)
        {
            // Assert: 应该返回 CategoryHasChildren 错误
            if (ex.Code != ErrorCodes.CategoryHasChildren) return false;

            // 验证父分类未被删除
            var parent = dbContext.ReportCategories.FirstOrDefault(c => c.Id == parentCategory.Id);
            return parent != null && !parent.IsDeleted;
        }
    }

    /// <summary>
    /// Property 18: 没有子分类的分类可以删除
    /// 
    /// **Validates: Requirements 6.6**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool DeletionConstraint_CategoryWithoutChildren_ShouldSucceedToDelete(PositiveInt seed)
    {
        // Arrange: 创建没有子分类的分类
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        var category = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Leaf {seed.Get}",
            Code = $"LEAF_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(category);
        dbContext.SaveChanges();

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

        // Act: 删除没有子分类的分类
        try
        {
            var result = service.DeleteCategoryAsync(category.Id).GetAwaiter().GetResult();

            // Assert: 应该删除成功（软删除）
            var deletedCategory = dbContext.ReportCategories.FirstOrDefault(c => c.Id == category.Id);
            return result && deletedCategory != null && deletedCategory.IsDeleted;
        }
        catch (BusinessException)
        {
            return false;
        }
    }

    /// <summary>
    /// Property 18: 删除子分类后，父分类可以被删除
    /// 
    /// **Validates: Requirements 6.6**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool DeletionConstraint_AfterChildDeleted_ParentCanBeDeleted(PositiveInt seed)
    {
        // Arrange: 创建父子分类
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        var parentCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Parent {seed.Get}",
            Code = $"PARENT_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(parentCategory);
        dbContext.SaveChanges();

        var childCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = parentCategory.Id,
            Name = $"Child {seed.Get}",
            Code = $"CHILD_{seed.Get}",
            CategoryType = 2,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(childCategory);
        dbContext.SaveChanges();

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

        // Act: 先删除子分类
        try
        {
            service.DeleteCategoryAsync(childCategory.Id).GetAwaiter().GetResult();
        }
        catch (BusinessException)
        {
            return false;
        }

        // 然后删除父分类
        try
        {
            var result = service.DeleteCategoryAsync(parentCategory.Id).GetAwaiter().GetResult();

            // Assert: 父分类应该被成功删除
            var parent = dbContext.ReportCategories.FirstOrDefault(c => c.Id == parentCategory.Id);
            return result && parent != null && parent.IsDeleted;
        }
        catch (BusinessException)
        {
            return false;
        }
    }

    /// <summary>
    /// Property 18: 有多个子分类的分类不能删除
    /// 
    /// **Validates: Requirements 6.6**
    /// </summary>
    [Property(MaxTest = 50)]
    public bool DeletionConstraint_CategoryWithMultipleChildren_ShouldFailToDelete(PositiveInt seed, PositiveInt childCount)
    {
        // 限制子分类数量为1-5
        var actualChildCount = (childCount.Get % 5) + 1;

        // Arrange: 创建父分类和多个子分类
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        var parentCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Parent {seed.Get}",
            Code = $"PARENT_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(parentCategory);
        dbContext.SaveChanges();

        // 创建多个子分类
        for (int i = 0; i < actualChildCount; i++)
        {
            var childCategory = new ReportCategory
            {
                AssessmentTypeId = assessmentTypeId,
                ParentId = parentCategory.Id,
                Name = $"Child {i} {seed.Get}",
                Code = $"CHILD_{i}_{seed.Get}",
                CategoryType = (i % 8) + 1,
                ScoreRule = 1,
                Sort = i,
                CreateTime = DateTime.Now,
                UpdateTime = DateTime.Now,
                IsDeleted = false
            };
            dbContext.ReportCategories.Add(childCategory);
        }
        dbContext.SaveChanges();

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

        // Act: 尝试删除有多个子分类的父分类
        try
        {
            service.DeleteCategoryAsync(parentCategory.Id).GetAwaiter().GetResult();
            return false; // 应该抛出异常
        }
        catch (BusinessException ex)
        {
            // Assert: 应该返回 CategoryHasChildren 错误
            if (ex.Code != ErrorCodes.CategoryHasChildren) return false;

            // 验证父分类未被删除
            var parent = dbContext.ReportCategories.FirstOrDefault(c => c.Id == parentCategory.Id);
            return parent != null && !parent.IsDeleted;
        }
    }

    /// <summary>
    /// Property 18: 软删除的子分类不应阻止父分类删除
    /// 
    /// **Validates: Requirements 6.6**
    /// </summary>
    [Property(MaxTest = 100)]
    public bool DeletionConstraint_SoftDeletedChildrenDontBlockParentDeletion(PositiveInt seed)
    {
        // Arrange: 创建父分类和已软删除的子分类
        using var dbContext = CreateDbContext();
        var assessmentTypeId = CreateAssessmentType(dbContext, seed.Get);

        var parentCategory = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = 0,
            Name = $"Parent {seed.Get}",
            Code = $"PARENT_{seed.Get}",
            CategoryType = 1,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.ReportCategories.Add(parentCategory);
        dbContext.SaveChanges();

        var softDeletedChild = new ReportCategory
        {
            AssessmentTypeId = assessmentTypeId,
            ParentId = parentCategory.Id,
            Name = $"Deleted Child {seed.Get}",
            Code = $"DELETED_CHILD_{seed.Get}",
            CategoryType = 2,
            ScoreRule = 1,
            Sort = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = true // 已软删除
        };
        dbContext.ReportCategories.Add(softDeletedChild);
        dbContext.SaveChanges();

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

        // Act: 删除父分类（子分类已软删除，不应阻止）
        try
        {
            var result = service.DeleteCategoryAsync(parentCategory.Id).GetAwaiter().GetResult();

            // Assert: 父分类应该被成功删除
            var parent = dbContext.ReportCategories.FirstOrDefault(c => c.Id == parentCategory.Id);
            return result && parent != null && parent.IsDeleted;
        }
        catch (BusinessException)
        {
            return false;
        }
    }

    #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>
    /// 创建测评类型并返回ID
    /// </summary>
    private long CreateAssessmentType(AdminBusinessDbContext dbContext, int seed)
    {
        var assessmentType = new AssessmentType
        {
            Name = $"Test Assessment {seed}",
            Code = $"TEST_{seed}_{Guid.NewGuid():N}".Substring(0, 20),
            Price = 99.99m,
            QuestionCount = 80,
            Sort = 1,
            Status = 1,
            CreateTime = DateTime.Now,
            UpdateTime = DateTime.Now,
            IsDeleted = false
        };
        dbContext.AssessmentTypes.Add(assessmentType);
        dbContext.SaveChanges();
        return assessmentType.Id;
    }

    #endregion
}