using NSubstitute.ReturnsExtensions;
using Service.Transaction;

namespace WebApi.Test.Budget;

/// <summary>
/// 预算统计 - 归档数据重复计算测试
/// </summary>
public class BudgetStatsArchiveTest : BaseTest
{
    private readonly IBudgetRepository _budgetRepo = Substitute.For<IBudgetRepository>();
    private readonly IBudgetArchiveRepository _archiveRepo = Substitute.For<IBudgetArchiveRepository>();
    private readonly ITransactionStatisticsService _transactionStatsService = Substitute.For<ITransactionStatisticsService>();
    private readonly IDateTimeProvider _dateTimeProvider = Substitute.For<IDateTimeProvider>();

    private IBudgetStatsService CreateService()
    {
        return new BudgetStatsService(
            _budgetRepo,
            _archiveRepo,
            _transactionStatsService,
            _dateTimeProvider,
            Substitute.For<ILogger<BudgetStatsService>>()
        );
    }

    /// <summary>
    /// 测试场景：当前为2月，用户切换到1月（已归档）查看预算
    /// 预期：年度统计不应重复计算1月的数据
    /// </summary>
    [Fact]
    public async Task GetCategoryStats_切换到已归档月份_年度统计不重复计算_Test()
    {
        // Arrange - 模拟当前时间为2026年2月1日
        var now = new DateTime(2026, 2, 1);
        _dateTimeProvider.Now.Returns(now);

        // 用户在前端选择查看1月的预算（referenceDate = 2026-01-01）
        var referenceDate = new DateTime(2026, 1, 1);

        // 创建一个月度预算：房贷
        var monthlyBudget = new BudgetRecord
        {
            Id = 100,
            Name = "房贷",
            Category = BudgetCategory.Expense,
            Type = BudgetPeriodType.Month,
            Limit = 9000, // 每月9000元
            StartDate = new DateTime(2026, 1, 1),
            SelectedCategories = "房贷",
            IsMandatoryExpense = false,
            NoLimit = false
        };

        // 当前预算列表
        _budgetRepo.GetAllAsync().Returns([monthlyBudget]);

        // 1月的归档数据（实际支出9158.7）
        var januaryArchive = new BudgetArchive
        {
            Year = 2026,
            Month = 1,
            Content = new[]
            {
                new BudgetArchiveContent
                {
                    Id = 100,
                    Name = "房贷",
                    Category = BudgetCategory.Expense,
                    Type = BudgetPeriodType.Month,
                    Limit = 9000,
                    Actual = 9158.7m, // 1月实际支出
                    SelectedCategories = ["房贷"],
                    IsMandatoryExpense = false,
                    NoLimit = false
                }
            }
        };
        _archiveRepo.GetArchiveAsync(2026, 1).Returns(januaryArchive);
        _archiveRepo.GetArchiveAsync(2026, 2).ReturnsNull();

        // 模拟2月的实际交易数据（假设2月到现在实际支出了3000）
        var feb1 = new DateTime(2026, 2, 1);
        var feb28 = new DateTime(2026, 2, 28);
        _budgetRepo.GetCurrentAmountAsync(
            Arg.Is<BudgetRecord>(b => b.Id == 100),
            Arg.Is<DateTime>(d => d >= feb1 && d <= feb28),
            Arg.Any<DateTime>()
        ).Returns(3000m);

        // 模拟交易统计数据（用于趋势图）
        _transactionStatsService.GetFilteredTrendStatisticsAsync(
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>(),
            TransactionType.Expense,
            Arg.Any<List<string>>(),
            true
        ).Returns(new Dictionary<DateTime, decimal>
        {
            { new DateTime(2026, 1, 1), 9158.7m }, // 1月
            { new DateTime(2026, 2, 1), 3000m }    // 2月
        });

        // 模拟月度统计的交易数据
        _transactionStatsService.GetFilteredTrendStatisticsAsync(
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>(),
            TransactionType.Expense,
            Arg.Any<List<string>>()
        ).Returns(new Dictionary<DateTime, decimal>
        {
            { new DateTime(2026, 1, 1), 9158.7m }
        });

        var service = CreateService();

        // Act - 调用获取分类统计（用户选择查看1月）
        var result = await service.GetCategoryStatsAsync(BudgetCategory.Expense, referenceDate);

        // Assert - 验证年度统计
        result.Should().NotBeNull();
        result.Year.Should().NotBeNull();

        // 年度预算限额 = 1月归档(9000) + 2月当前(9000) + 未来10个月(9000 * 10) = 108000
        result.Year.Limit.Should().Be(108000);

        // 年度实际支出 = 1月归档(9158.7) + 2月当前(3000) = 12158.7
        // 关键：不应该包含两次1月的数据！
        result.Year.Current.Should().Be(12158.7m);

        // 使用率 = 12158.7 / 108000 * 100 = 11.26%
        result.Year.Rate.Should().BeApproximately(11.26m, 0.01m);
    }

    /// <summary>
    /// 测试场景：当前为2月，用户切换到1月（已归档）查看预算，包含年度预算
    /// 预期：年度预算只计算一次
    /// </summary>
    [Fact]
    public async Task GetCategoryStats_年度预算_切换到已归档月份_不重复计算_Test()
    {
        // Arrange - 模拟当前时间为2026年2月1日
        var now = new DateTime(2026, 2, 1);
        _dateTimeProvider.Now.Returns(now);

        var referenceDate = new DateTime(2026, 1, 1);

        // 创建年度预算和月度预算
        var yearlyBudget = new BudgetRecord
        {
            Id = 200,
            Name = "教育费",
            Category = BudgetCategory.Expense,
            Type = BudgetPeriodType.Year,
            Limit = 8000, // 全年8000元
            StartDate = new DateTime(2026, 1, 1),
            SelectedCategories = "教育",
            IsMandatoryExpense = false,
            NoLimit = false
        };

        var monthlyBudget = new BudgetRecord
        {
            Id = 100,
            Name = "生活费",
            Category = BudgetCategory.Expense,
            Type = BudgetPeriodType.Month,
            Limit = 2000,
            StartDate = new DateTime(2026, 1, 1),
            SelectedCategories = "餐饮",
            IsMandatoryExpense = false,
            NoLimit = false
        };

        _budgetRepo.GetAllAsync().Returns([yearlyBudget, monthlyBudget]);

        // 1月归档数据
        var januaryArchive = new BudgetArchive
        {
            Year = 2026,
            Month = 1,
            Content = new[]
            {
                new BudgetArchiveContent
                {
                    Id = 200,
                    Name = "教育费",
                    Category = BudgetCategory.Expense,
                    Type = BudgetPeriodType.Year,
                    Limit = 8000,
                    Actual = 7257m, // 全年实际（从1月累计）
                    SelectedCategories = ["教育"],
                    IsMandatoryExpense = false,
                    NoLimit = false
                },
                new BudgetArchiveContent
                {
                    Id = 100,
                    Name = "生活费",
                    Category = BudgetCategory.Expense,
                    Type = BudgetPeriodType.Month,
                    Limit = 2000,
                    Actual = 2000m, // 1月实际
                    SelectedCategories = ["餐饮"],
                    IsMandatoryExpense = false,
                    NoLimit = false
                }
            }
        };
        _archiveRepo.GetArchiveAsync(2026, 1).Returns(januaryArchive);
        _archiveRepo.GetArchiveAsync(2026, 2).ReturnsNull();

        // 2月的实际数据
        var feb1 = new DateTime(2026, 2, 1);
        var feb28 = new DateTime(2026, 2, 28);
        _budgetRepo.GetCurrentAmountAsync(
            Arg.Is<BudgetRecord>(b => b.Id == 100),
            Arg.Is<DateTime>(d => d >= feb1 && d <= feb28),
            Arg.Any<DateTime>()
        ).Returns(1800m);

        // 年度预算的当前实际值（整年累计，包括1月归档的7257）
        var year1 = new DateTime(2026, 1, 1);
        var year12 = new DateTime(2026, 12, 31);
        _budgetRepo.GetCurrentAmountAsync(
            Arg.Is<BudgetRecord>(b => b.Id == 200),
            Arg.Is<DateTime>(d => d >= year1),
            Arg.Any<DateTime>()
        ).Returns(7257m); // 全年累计

        _transactionStatsService.GetFilteredTrendStatisticsAsync(
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>(),
            TransactionType.Expense,
            Arg.Any<List<string>>(),
            true
        ).Returns(new Dictionary<DateTime, decimal>
        {
            { new DateTime(2026, 1, 1), 9257m }, // 1月: 教育7257 + 生活2000
            { new DateTime(2026, 2, 1), 1800m }  // 2月: 生活1800
        });

        // 模拟月度统计的交易数据
        _transactionStatsService.GetFilteredTrendStatisticsAsync(
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>(),
            TransactionType.Expense,
            Arg.Any<List<string>>()
        ).Returns(new Dictionary<DateTime, decimal>
        {
            { new DateTime(2026, 1, 1), 9257m }
        });

        var service = CreateService();

        // Act
        var result = await service.GetCategoryStatsAsync(BudgetCategory.Expense, referenceDate);

        // Assert
        result.Year.Should().NotBeNull();

        // 年度限额 = 教育费(8000) + 生活费1月归档(2000) + 生活费2月(2000) + 生活费未来10月(2000*10) = 32000
        result.Year.Limit.Should().Be(32000);

        // 年度实际支出 = 教育费(7257) + 生活费1月(2000) + 生活费2月(1800) = 11057
        // 关键：教育费（年度预算）只应该计算一次！
        result.Year.Current.Should().Be(11057m);
    }

    /// <summary>
    /// 测试场景：当前为3月，用户切换到1月查看
    /// 预期：年度统计应包含1月归档 + 2月归档 + 3月当前
    /// </summary>
    [Fact]
    public async Task GetCategoryStats_多个归档月份_不重复计算_Test()
    {
        // Arrange - 模拟当前时间为2026年3月15日
        var now = new DateTime(2026, 3, 15);
        _dateTimeProvider.Now.Returns(now);

        var referenceDate = new DateTime(2026, 1, 1);

        var monthlyBudget = new BudgetRecord
        {
            Id = 100,
            Name = "房贷",
            Category = BudgetCategory.Expense,
            Type = BudgetPeriodType.Month,
            Limit = 9000,
            StartDate = new DateTime(2026, 1, 1),
            SelectedCategories = "房贷",
            IsMandatoryExpense = false,
            NoLimit = false
        };

        _budgetRepo.GetAllAsync().Returns([monthlyBudget]);

        // 1月归档
        _archiveRepo.GetArchiveAsync(2026, 1).Returns(new BudgetArchive
        {
            Year = 2026,
            Month = 1,
            Content = new[]
            {
                new BudgetArchiveContent
                {
                    Id = 100,
                    Name = "房贷",
                    Category = BudgetCategory.Expense,
                    Type = BudgetPeriodType.Month,
                    Limit = 9000,
                    Actual = 9158.7m,
                    SelectedCategories = ["房贷"],
                    IsMandatoryExpense = false,
                    NoLimit = false
                }
            }
        });

        // 2月归档
        _archiveRepo.GetArchiveAsync(2026, 2).Returns(new BudgetArchive
        {
            Year = 2026,
            Month = 2,
            Content = new[]
            {
                new BudgetArchiveContent
                {
                    Id = 100,
                    Name = "房贷",
                    Category = BudgetCategory.Expense,
                    Type = BudgetPeriodType.Month,
                    Limit = 9000,
                    Actual = 9126.1m,
                    SelectedCategories = ["房贷"],
                    IsMandatoryExpense = false,
                    NoLimit = false
                }
            }
        });

        _archiveRepo.GetArchiveAsync(2026, 3).ReturnsNull();

        // 3月当前实际数据（到3月15日）
        _budgetRepo.GetCurrentAmountAsync(
            Arg.Is<BudgetRecord>(b => b.Id == 100),
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>()
        ).Returns(4500m); // 3月已支出4500

        _transactionStatsService.GetFilteredTrendStatisticsAsync(
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>(),
            TransactionType.Expense,
            Arg.Any<List<string>>(),
            true
        ).Returns(new Dictionary<DateTime, decimal>
        {
            { new DateTime(2026, 1, 1), 9158.7m },
            { new DateTime(2026, 2, 1), 9126.1m },
            { new DateTime(2026, 3, 1), 4500m }
        });

        // 模拟月度统计的交易数据
        _transactionStatsService.GetFilteredTrendStatisticsAsync(
            Arg.Any<DateTime>(),
            Arg.Any<DateTime>(),
            TransactionType.Expense,
            Arg.Any<List<string>>()
        ).Returns(new Dictionary<DateTime, decimal>
        {
            { new DateTime(2026, 1, 1), 9158.7m }
        });

        var service = CreateService();

        // Act
        var result = await service.GetCategoryStatsAsync(BudgetCategory.Expense, referenceDate);

        // Assert
        result.Year.Should().NotBeNull();

        // 年度限额 = 1月归档(9000) + 2月归档(9000) + 3月当前(9000) + 未来9月(9000*9) = 108000
        result.Year.Limit.Should().Be(108000);

        // 年度实际 = 1月归档(9158.7) + 2月归档(9126.1) + 3月当前(4500) = 22784.8
        result.Year.Current.Should().Be(22784.8m);

        // 验证每个月只计算了一次
        result.Year.Rate.Should().BeApproximately(21.10m, 0.01m);
    }
}