using AutoMapper;
using HardwarePerformance.Models;
using HardwarePerformance.Models.DTOs;
using HardwarePerformance.Services;
using Moq;

namespace HardwarePerformance.Tests.Services
{
    public class ProductServiceTests
    {
        private readonly Mock<IProductRepository> _mockProductRepository;
        private readonly Mock<IMapper> _mockMapper;
        private readonly ProductService _productService;

        public ProductServiceTests()
        {
            _mockProductRepository = new Mock<IProductRepository>();
            _mockMapper = new Mock<IMapper>();
            _productService = new ProductService(_mockProductRepository.Object, _mockMapper.Object);
        }

        [Fact]
        public async Task GetProductsByCategoryAsync_ReturnsPagedProducts()
        {
            // Arrange
            var categoryId = 1;
            var page = 1;
            var pageSize = 10;
            var sortBy = "Name";
            var sortOrder = "asc";

            var products = new List<Product>
            {
                new Product { Id = 1, Name = "Intel Core i9", CategoryId = categoryId },
                new Product { Id = 2, Name = "AMD Ryzen 9", CategoryId = categoryId }
            };

            var productDtos = new List<ProductListDto>
            {
                new ProductListDto { Id = 1, Name = "Intel Core i9" },
                new ProductListDto { Id = 2, Name = "AMD Ryzen 9" }
            };

            var pagedResult = new PagedResultDto<ProductListDto>
            {
                Items = productDtos,
                TotalCount = 2,
                Page = page,
                PageSize = pageSize
            };

            _mockProductRepository.Setup(repo => repo.GetByCategoryAsync(categoryId, page, pageSize, sortBy, sortOrder))
                .ReturnsAsync(products);

            _mockProductRepository.Setup(repo => repo.CountAsync(categoryId))
                .ReturnsAsync(2);

            _mockMapper.Setup(m => m.Map<IEnumerable<ProductListDto>>(products))
                .Returns(productDtos);

            // Act
            var result = await _productService.GetProductsByCategoryAsync(categoryId, page, pageSize, sortBy, sortOrder);

            // Assert
            Assert.NotNull(result);
            Assert.Equal(2, result.TotalCount);
            Assert.Equal(2, result.Items.Count());
            _mockProductRepository.Verify(repo => repo.GetByCategoryAsync(categoryId, page, pageSize, sortBy, sortOrder), Times.Once);
            _mockProductRepository.Verify(repo => repo.CountAsync(categoryId), Times.Once);
            _mockMapper.Verify(m => m.Map<IEnumerable<ProductListDto>>(products), Times.Once);
        }

        [Fact]
        public async Task GetProductByIdAsync_ExistingProduct_ReturnsProductDto()
        {
            // Arrange
            var productId = 1;
            var product = new Product 
            { 
                Id = productId, 
                Name = "Intel Core i9", 
                CategoryId = 1,
                PerformanceScores = new List<PerformanceScore>(),
                Specifications = new List<Specification>()
            };
            
            var productDto = new ProductDto 
            { 
                Id = productId, 
                Name = "Intel Core i9", 
                CategoryId = 1,
                PerformanceScores = new List<PerformanceScore>(),
                Specifications = new List<Specification>()
            };

            _mockProductRepository.Setup(repo => repo.GetByIdAsync(productId))
                .ReturnsAsync(product);

            _mockMapper.Setup(m => m.Map<ProductDto>(product))
                .Returns(productDto);

            // Act
            var result = await _productService.GetProductByIdAsync(productId);

            // Assert
            Assert.NotNull(result);
            Assert.Equal(productId, result.Id);
            Assert.Equal("Intel Core i9", result.Name);
            _mockProductRepository.Verify(repo => repo.GetByIdAsync(productId), Times.Once);
            _mockMapper.Verify(m => m.Map<ProductDto>(product), Times.Once);
        }

        [Fact]
        public async Task GetProductByIdAsync_NonExistingProduct_ReturnsNull()
        {
            // Arrange
            var productId = 999;

            _mockProductRepository.Setup(repo => repo.GetByIdAsync(productId))
                .ReturnsAsync((Product?)null);

            // Act
            var result = await _productService.GetProductByIdAsync(productId);

            // Assert
            Assert.Null(result);
            _mockProductRepository.Verify(repo => repo.GetByIdAsync(productId), Times.Once);
            _mockMapper.Verify(m => m.Map<ProductDto>(It.IsAny<Product>()), Times.Never);
        }

        [Fact]
        public async Task SearchProductsAsync_ReturnsPagedSearchResults()
        {
            // Arrange
            var query = "Intel";
            var categoryId = 1;
            var manufacturer = "Intel";
            var minScore = 1000;
            var maxScore = 5000;
            var page = 1;
            var pageSize = 10;

            var products = new List<Product>
            {
                new Product { Id = 1, Name = "Intel Core i9", Manufacturer = "Intel", CategoryId = categoryId, PerformanceScore = 4000 },
                new Product { Id = 2, Name = "Intel Core i7", Manufacturer = "Intel", CategoryId = categoryId, PerformanceScore = 3000 }
            };

            var productDtos = new List<ProductListDto>
            {
                new ProductListDto { Id = 1, Name = "Intel Core i9" },
                new ProductListDto { Id = 2, Name = "Intel Core i7" }
            };

            var pagedResult = new PagedResultDto<ProductListDto>
            {
                Items = productDtos,
                TotalCount = 2,
                Page = page,
                PageSize = pageSize
            };

            _mockProductRepository.Setup(repo => repo.SearchAsync(query, categoryId, manufacturer, minScore, maxScore, page, pageSize))
                .ReturnsAsync(products);

            _mockProductRepository.Setup(repo => repo.CountSearchResultsAsync(query, categoryId, manufacturer, minScore, maxScore))
                .ReturnsAsync(2);

            _mockMapper.Setup(m => m.Map<IEnumerable<ProductListDto>>(products))
                .Returns(productDtos);

            // Act
            var result = await _productService.SearchProductsAsync(query, categoryId, manufacturer, minScore, maxScore, page, pageSize);

            // Assert
            Assert.NotNull(result);
            Assert.Equal(2, result.TotalCount);
            Assert.Equal(2, result.Items.Count());
            _mockProductRepository.Verify(repo => repo.SearchAsync(query, categoryId, manufacturer, minScore, maxScore, page, pageSize), Times.Once);
            _mockProductRepository.Verify(repo => repo.CountSearchResultsAsync(query, categoryId, manufacturer, minScore, maxScore), Times.Once);
            _mockMapper.Verify(m => m.Map<IEnumerable<ProductListDto>>(products), Times.Once);
        }
    }
}