EmailBill/WebApi.Test/Budget/BudgetSavingsCalculationTest.cs

using Service.Budget;

namespace WebApi.Test.Budget;

/// <summary>
/// 存款计划核心公式单元测试
/// </summary>
public class BudgetSavingsCalculationTest : BaseTest
{
    [Fact]
    public void 月度计划存款公式_纯月度预算场景()
    {
        // Arrange
        var monthlyIncomeBudget = 15000m; // 工资10000 + 奖金5000
        var yearlyIncomeInThisMonth = 0m;
        var monthlyExpenseBudget = 5000m; // 房租3000 + 餐饮2000
        var yearlyExpenseInThisMonth = 0m;
        
        // Act
        var result = BudgetSavingsService.CalculateMonthlyPlannedSavings(
            monthlyIncomeBudget,
            yearlyIncomeInThisMonth,
            monthlyExpenseBudget,
            yearlyExpenseInThisMonth
        );
        
        // Assert
        result.Should().Be(10000m); // 15000 - 5000
    }

    [Fact]
    public void 月度计划存款公式_月度预算加本月发生的年度预算()
    {
        // Arrange
        var monthlyIncomeBudget = 10000m; // 工资
        var yearlyIncomeInThisMonth = 0m;
        var monthlyExpenseBudget = 3000m; // 房租
        var yearlyExpenseInThisMonth = 3000m; // 旅游实际发生
        
        // Act
        var result = BudgetSavingsService.CalculateMonthlyPlannedSavings(
            monthlyIncomeBudget,
            yearlyIncomeInThisMonth,
            monthlyExpenseBudget,
            yearlyExpenseInThisMonth
        );
        
        // Assert
        result.Should().Be(4000m); // 10000 - 3000 - 3000
    }

    [Fact]
    public void 月度计划存款公式_年度预算未在本月发生应不计入()
    {
        // Arrange
        var monthlyIncomeBudget = 10000m;
        var yearlyIncomeInThisMonth = 0m; // 年终奖未发生
        var monthlyExpenseBudget = 3000m;
        var yearlyExpenseInThisMonth = 0m; // 旅游未发生
        
        // Act
        var result = BudgetSavingsService.CalculateMonthlyPlannedSavings(
            monthlyIncomeBudget,
            yearlyIncomeInThisMonth,
            monthlyExpenseBudget,
            yearlyExpenseInThisMonth
        );
        
        // Assert
        result.Should().Be(7000m); // 10000 - 3000
    }

    [Fact]
    public void 年度计划存款公式_年初无归档数据场景()
    {
        // Arrange
        var archivedIncome = 0m;
        var futureIncomeBudget = 120000m; // 10000×12
        var archivedExpense = 0m;
        var futureExpenseBudget = 36000m; // 3000×12
        
        // Act
        var result = BudgetSavingsService.CalculateYearlyPlannedSavings(
            archivedIncome,
            futureIncomeBudget,
            archivedExpense,
            futureExpenseBudget
        );
        
        // Assert
        result.Should().Be(84000m); // 120000 - 36000
    }

    [Fact]
    public void 年度计划存款公式_年中有归档数据场景()
    {
        // Arrange
        var archivedIncome = 29000m; // 1月15000 + 2月14000
        var futureIncomeBudget = 100000m; // 10000×10月
        var archivedExpense = 10000m; // 1月4800 + 2月5200
        var futureExpenseBudget = 30000m; // 3000×10月
        
        // Act
        var result = BudgetSavingsService.CalculateYearlyPlannedSavings(
            archivedIncome,
            futureIncomeBudget,
            archivedExpense,
            futureExpenseBudget
        );
        
        // Assert
        result.Should().Be(89000m); // 29000 + 100000 - 10000 - 30000
    }

    [Fact]
    public void 年度计划存款公式_归档数据包含年度预算()
    {
        // Arrange
        var archivedIncome = 15000m;
        var futureIncomeBudget = 110000m;
        var archivedExpense = 7800m; // 包含1月旅游3000的年度支出
        var futureExpenseBudget = 30000m;
        
        // Act
        var result = BudgetSavingsService.CalculateYearlyPlannedSavings(
            archivedIncome,
            futureIncomeBudget,
            archivedExpense,
            futureExpenseBudget
        );
        
        // Assert
        result.Should().Be(87200m); // 15000 + 110000 - 7800 - 30000
    }
}