using Xunit;
using Moq;
using System.Linq;
using System.Collections.Generic;
using Infrastructure;
using Infrastructure.Entities;
using Microsoft.EntityFrameworkCore;
using Server.Dto.Request;
using Server.Services;
using Shared.Criteria;

public class AlumniServiceTests
{
    private readonly Mock<AlumniDbContext> _mockContext;
    private readonly AlumniService _alumniService;

    public AlumniServiceTests()
    {
        var alumni = new List<User>
        {
            new User { Id = "1", LastName = "Alumni1" },
            new User { Id = "2", LastName = "Alumni2" }
        }.AsQueryable();

        var mockSet = new Mock<DbSet<User>>();
        mockSet.As<IQueryable<User>>().Setup(m => m.Provider).Returns(alumni.Provider);
        mockSet.As<IQueryable<User>>().Setup(m => m.Expression).Returns(alumni.Expression);
        mockSet.As<IQueryable<User>>().Setup(m => m.ElementType).Returns(alumni.ElementType);
        mockSet.As<IQueryable<User>>().Setup(m => m.GetEnumerator()).Returns(alumni.GetEnumerator());

        _mockContext = new Mock<AlumniDbContext>();
        _mockContext.Setup(c => c.Alumni).Returns(mockSet.Object);

        _alumniService = new AlumniService(_mockContext.Object);
    }

    [Fact]
    public async Task GetAlumniById_ReturnsNull_WhenIdDoesNotExist()
    {
        var result = await _alumniService.GetAlumniById("3");
        Assert.Null(result);
    }
    

    [Fact]
    public async Task GetAlumnis_ReturnsEmpty_WhenLastNameDoesNotExist()
    {
        var result = await _alumniService.GetAlumnis("Alumni3", 1, 1, AlumniOrderCriteria.Name, true);
        Assert.Empty(result.Alumnis);
    }


    [Fact]
    public async Task GetAlumnisRestricted_NoMatchingLastName_ReturnsEmpty()
    {
        // Arrange
        string lastName = "NonExistingLastName";
        var page = 1;
        var size = 5;

        // Act
        var result = await _alumniService.GetAlumnisRestricted(lastName, page, size);

        // Assert
        Assert.Empty(result.Alumnis);
    }

    [Fact]
    public async Task GetAlumnisRestricted_MatchingLastName_ReturnsAlumni()
    {
        // Arrange
        string lastName = "Alumni1"; 
        var page = 1;
        var size = 5;

        // Act
        var result = await _alumniService.GetAlumnisRestricted(lastName, page, size);

        // Assert
        Assert.NotEmpty(result.Alumnis);
        Assert.Equal(1, result.Alumnis.Count());
        Assert.Equal("Alumni1", result.Alumnis.First().LastName);
    }

    [Fact]
    public async Task GetAlumnisRestricted_PaginationWorksCorrectly()
    {
        // Arrange
        string lastName = null; 
        var page = 2;
        var size = 1; 

        // Act
        var result = await _alumniService.GetAlumnisRestricted(lastName, page, size);

        // Assert
        Assert.NotEmpty(result.Alumnis);
        Assert.Single(result.Alumnis);
        Assert.Equal("Alumni2", result.Alumnis.First().LastName);
    }
}