using System.Security.Claims;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
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 ROLAC.API.Services.Logging;
using Xunit;

namespace ROLAC.API.Tests.Services;

public class ExpenseSnapshotServiceTests
{
    private static AppDbContext BuildDb(string userId)
    {
        var claims = new[] { new Claim(ClaimTypes.NameIdentifier, userId) };
        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 CurrentUserAccessor(mock.Object))).Options);
    }

    private static (ExpenseSnapshotService svc, AppDbContext db) Build(string userId = "u1")
    {
        var db = BuildDb(userId);
        db.Ministries.Add(new Ministry { Id = 1, Name_en = "Worship", Name_zh = "敬拜" });
        db.ExpenseCategoryGroups.Add(new ExpenseCategoryGroup { Id = 1, Name_en = "Facilities" });
        db.ExpenseSubCategories.Add(new ExpenseSubCategory { Id = 1, GroupId = 1, Name_en = "Rent" });
        db.SaveChanges();
        return (new ExpenseSnapshotService(db), db);
    }

    private static CreateExpenseSnapshotRequest Rent() => new()
    {
        Name = "Monthly Rent", MinistryId = 1, Description = "Office rent", VendorName = "Landlord X",
        CheckNumber = "1001",
        Lines = { new ExpenseLineInput { CategoryGroupId = 1, SubCategoryId = 1, Amount = 1200m } },
    };

    [Fact]
    public async Task Create_PersistsHeaderAndLines_StampsCreator()
    {
        var (svc, db) = Build("creator-1");
        var id = await svc.CreateAsync(Rent());

        var saved = await db.ExpenseSnapshots.FindAsync(id);
        Assert.Equal("Monthly Rent", saved!.Name);
        Assert.Equal("creator-1", saved.CreatedBy);
        Assert.Equal(1, await db.ExpenseSnapshotLines.CountAsync(l => l.SnapshotId == id));
    }

    [Fact]
    public async Task Create_WithNoLines_Throws()
    {
        var (svc, _) = Build();
        var r = Rent(); r.Lines.Clear();
        await Assert.ThrowsAsync<InvalidOperationException>(() => svc.CreateAsync(r));
    }

    [Fact]
    public async Task GetById_ReturnsLines_TotalsAndCreatorName()
    {
        var (svc, db) = Build("creator-1");
        db.Members.Add(new Member { Id = 5, FirstName_en = "Joy", LastName_en = "Wong" });
        db.Users.Add(new AppUser { Id = "creator-1", MemberId = 5 });
        await db.SaveChangesAsync();

        var id = await svc.CreateAsync(Rent());
        var dto = await svc.GetByIdAsync(id);

        Assert.NotNull(dto);
        Assert.Equal(1200m, dto!.TotalAmount);
        Assert.Equal(1, dto.LineCount);
        Assert.Equal("Rent", dto.Lines.Single().SubCategoryName);
        Assert.Equal("Joy Wong", dto.CreatedByName);
    }

    [Fact]
    public async Task GetAll_ReturnsNewestFirst()
    {
        var (svc, _) = Build();
        var first  = await svc.CreateAsync(Rent());
        var second = await svc.CreateAsync(Rent());

        var all = await svc.GetAllAsync();

        Assert.Equal(2, all.Count);
        Assert.Equal(second, all[0].Id);
        Assert.Equal(first,  all[1].Id);
    }

    [Fact]
    public async Task Update_RenamesAndReplacesLines()
    {
        var (svc, db) = Build();
        db.ExpenseCategoryGroups.Add(new ExpenseCategoryGroup { Id = 2, Name_en = "Utilities" });
        db.ExpenseSubCategories.Add(new ExpenseSubCategory { Id = 2, GroupId = 2, Name_en = "Internet" });
        await db.SaveChangesAsync();

        var id = await svc.CreateAsync(Rent());
        await svc.UpdateAsync(id, new UpdateExpenseSnapshotRequest
        {
            Name = "Monthly Internet", MinistryId = 1, Description = "ISP",
            Lines = { new ExpenseLineInput { CategoryGroupId = 2, SubCategoryId = 2, Amount = 80m } },
        });

        var dto = await svc.GetByIdAsync(id);
        Assert.Equal("Monthly Internet", dto!.Name);
        Assert.Equal(80m, dto.TotalAmount);
        Assert.Equal("Internet", dto.Lines.Single().SubCategoryName);
        Assert.Equal(1, await db.ExpenseSnapshotLines.CountAsync(l => l.SnapshotId == id));
    }

    [Fact]
    public async Task Update_MissingId_Throws()
    {
        var (svc, _) = Build();
        await Assert.ThrowsAsync<KeyNotFoundException>(() => svc.UpdateAsync(999, new UpdateExpenseSnapshotRequest
        {
            Name = "x", MinistryId = 1, Description = "x",
            Lines = { new ExpenseLineInput { CategoryGroupId = 1, SubCategoryId = 1, Amount = 1m } },
        }));
    }

    [Fact]
    public async Task Delete_SoftDeletes_HidesFromQueries()
    {
        var (svc, db) = Build();
        var id = await svc.CreateAsync(Rent());

        await svc.DeleteAsync(id);

        Assert.Empty(await svc.GetAllAsync());
        Assert.Null(await db.ExpenseSnapshots.FirstOrDefaultAsync(s => s.Id == id));
    }
}