using Microsoft.EntityFrameworkCore;
using System.Security.Claims;
using Microsoft.AspNetCore.Http;
using Moq;
using ROLAC.API.Data;
using ROLAC.API.Data.Interceptors;
using ROLAC.API.DTOs.Expense;
using ROLAC.API.Entities;
using ROLAC.API.Services;
using Xunit;

namespace ROLAC.API.Tests.Services;

public class MonthlyStatementServiceTests
{
    private static AppDbContext BuildDb()
    {
        var claims = new[] { new Claim(ClaimTypes.NameIdentifier, "test-user") };
        var ctx    = new DefaultHttpContext { User = new(new ClaimsIdentity(claims)) };
        var mock   = new Mock<IHttpContextAccessor>();
        mock.Setup(x => x.HttpContext).Returns(ctx);
        return new AppDbContext(new DbContextOptionsBuilder<AppDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .AddInterceptors(new AuditSaveChangesInterceptor(new ROLAC.API.Services.Logging.CurrentUserAccessor(mock.Object))).Options);
    }

    private static MonthlyStatementService Build(AppDbContext db)
    {
        var mock = new Mock<IHttpContextAccessor>();
        var ctx  = new DefaultHttpContext { User = new(new ClaimsIdentity(new[] { new Claim(ClaimTypes.NameIdentifier, "test-user") })) };
        mock.Setup(x => x.HttpContext).Returns(ctx);
        return new MonthlyStatementService(db, mock.Object, ROLAC.API.Tests.TestSupport.NullAuditLogger.Instance);
    }

    [Fact]
    public async Task Create_ComputesGivingAndPaidExpenses_ForMonthOnly()
    {
        using var db = BuildDb();
        db.GivingCategories.Add(new GivingCategory { Id = 1, Name_en = "Tithe" });
        db.Ministries.Add(new Ministry { Id = 1, Name_en = "Admin" });
        db.ExpenseCategoryGroups.Add(new ExpenseCategoryGroup { Id = 1, Name_en = "Other" });
        db.ExpenseSubCategories.Add(new ExpenseSubCategory { Id = 1, GroupId = 1, Name_en = "Misc" });
        db.Givings.Add(new Giving { GivingCategoryId = 1, Amount = 1000m, PaymentMethod = "Cash", GivingDate = new DateOnly(2026, 5, 10) });
        db.Givings.Add(new Giving { GivingCategoryId = 1, Amount = 500m,  PaymentMethod = "Cash", GivingDate = new DateOnly(2026, 6, 1) });
        db.Expenses.Add(new Expense { MinistryId = 1, CategoryGroupId = 1, SubCategoryId = 1, Type = "VendorPayment", Status = "Paid", Amount = 300m, Description = "x", ExpenseDate = new DateOnly(2026, 5, 20) });
        db.Expenses.Add(new Expense { MinistryId = 1, CategoryGroupId = 1, SubCategoryId = 1, Type = "StaffReimbursement", Status = "Approved", Amount = 999m, Description = "not paid", ExpenseDate = new DateOnly(2026, 5, 21) });
        await db.SaveChangesAsync();
        var svc = Build(db);

        var id = await svc.CreateAsync(new CreateMonthlyStatementRequest
        { Year = 2026, Month = 5, OpeningBalance = 2000m, TotalOtherIncome = 100m, BankStatementBalance = 2800m });

        var dto = await svc.GetByIdAsync(id);
        Assert.Equal(1000m, dto!.TotalGiving);
        Assert.Equal(300m, dto.TotalExpenses);
        Assert.Equal(2800m, dto.CalculatedClosingBalance);
        Assert.Equal(0m, dto.Difference);
    }

    [Fact]
    public async Task Create_Duplicate_Throws()
    {
        using var db = BuildDb();
        var svc = Build(db);
        await svc.CreateAsync(new CreateMonthlyStatementRequest { Year = 2026, Month = 5 });
        await Assert.ThrowsAsync<InvalidOperationException>(() =>
            svc.CreateAsync(new CreateMonthlyStatementRequest { Year = 2026, Month = 5 }));
    }

    [Fact]
    public async Task Update_AfterFinalize_Throws()
    {
        using var db = BuildDb();
        var svc = Build(db);
        var id = await svc.CreateAsync(new CreateMonthlyStatementRequest { Year = 2026, Month = 5 });
        await svc.FinalizeAsync(id);
        await Assert.ThrowsAsync<InvalidOperationException>(() =>
            svc.UpdateAsync(id, new UpdateMonthlyStatementRequest { OpeningBalance = 1m }));
    }
}