using System.Net;
using System.Net.Http.Json;
using System.Text.Json;
using FluentAssertions;
using LittleShop.DTOs;
using LittleShop.Models;
using LittleShop.Tests.Infrastructure;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Extensions.DependencyInjection;
using Xunit;

namespace LittleShop.Tests.Integration;

public class OrdersWithVariantsTests : IClassFixture<TestWebApplicationFactory>
{
    private readonly HttpClient _client;
    private readonly TestWebApplicationFactory _factory;

    public OrdersWithVariantsTests(TestWebApplicationFactory factory)
    {
        _factory = factory;
        _client = _factory.CreateClient(new WebApplicationFactoryClientOptions
        {
            AllowAutoRedirect = false
        });
    }

    [Fact]
    public async Task CreateOrder_WithVariants_ShouldStoreVariantInfo()
    {
        // Arrange
        var product = await CreateProductWithVariants();

        var orderRequest = new CreateOrderDto
        {
            IdentityReference = "test_user_" + Guid.NewGuid(),
            ShippingName = "John Doe",
            ShippingAddress = "123 Test St",
            ShippingCity = "Test City",
            ShippingPostCode = "TE1 1ST",
            ShippingCountry = "United Kingdom",
            Items = new List<CreateOrderItemDto>
            {
                new()
                {
                    ProductId = product.Id,
                    Quantity = 1,
                    SelectedVariant = "Red"
                },
                new()
                {
                    ProductId = product.Id,
                    Quantity = 2,
                    SelectedVariant = "Blue"
                }
            }
        };

        // Act
        var response = await _client.PostAsJsonAsync("/api/orders", orderRequest);

        // Assert
        response.StatusCode.Should().Be(HttpStatusCode.Created);

        var order = await response.Content.ReadFromJsonAsync<OrderDto>();
        order.Should().NotBeNull();
        order!.Items.Should().HaveCount(2);
        order.Items.Should().Contain(i => i.SelectedVariant == "Red" && i.Quantity == 1);
        order.Items.Should().Contain(i => i.SelectedVariant == "Blue" && i.Quantity == 2);
    }

    [Fact]
    public async Task CreateOrder_WithMultiBuy_ShouldApplyMultiBuyPricing()
    {
        // Arrange
        var product = await CreateProductWithMultiBuys();
        var multiBuy = product.MultiBuys.First(mb => mb.Quantity == 3);

        var orderRequest = new CreateOrderDto
        {
            IdentityReference = "test_user_" + Guid.NewGuid(),
            ShippingName = "Jane Doe",
            ShippingAddress = "456 Test Ave",
            ShippingCity = "Test Town",
            ShippingPostCode = "TT2 2ST",
            ShippingCountry = "United Kingdom",
            Items = new List<CreateOrderItemDto>
            {
                new()
                {
                    ProductId = product.Id,
                    ProductMultiBuyId = multiBuy.Id,
                    Quantity = 3
                }
            }
        };

        // Act
        var response = await _client.PostAsJsonAsync("/api/orders", orderRequest);

        // Assert
        response.StatusCode.Should().Be(HttpStatusCode.Created);

        var order = await response.Content.ReadFromJsonAsync<OrderDto>();
        order.Should().NotBeNull();
        order!.Items.Should().HaveCount(1);

        var item = order.Items.First();
        item.Quantity.Should().Be(3);
        item.ProductMultiBuyId.Should().Be(multiBuy.Id);
        item.UnitPrice.Should().Be(multiBuy.PricePerUnit);
        item.TotalPrice.Should().Be(multiBuy.Price);
    }

    [Fact]
    public async Task CreateOrder_WithMultiBuyAndVariant_ShouldStoreBoth()
    {
        // Arrange
        var product = await CreateProductWithMultiBuysAndVariants();
        var multiBuy = product.MultiBuys.First(mb => mb.Quantity == 2);

        var orderRequest = new CreateOrderDto
        {
            IdentityReference = "test_user_" + Guid.NewGuid(),
            ShippingName = "Bob Smith",
            ShippingAddress = "789 Test Rd",
            ShippingCity = "Testville",
            ShippingPostCode = "TV3 3ST",
            ShippingCountry = "United Kingdom",
            Items = new List<CreateOrderItemDto>
            {
                new()
                {
                    ProductId = product.Id,
                    ProductMultiBuyId = multiBuy.Id,
                    Quantity = 2,
                    SelectedVariant = "Vanilla"
                }
            }
        };

        // Act
        var response = await _client.PostAsJsonAsync("/api/orders", orderRequest);

        // Assert
        response.StatusCode.Should().Be(HttpStatusCode.Created);

        var order = await response.Content.ReadFromJsonAsync<OrderDto>();
        order.Should().NotBeNull();

        var item = order.Items.First();
        item.ProductMultiBuyId.Should().Be(multiBuy.Id);
        item.SelectedVariant.Should().Be("Vanilla");
        item.Quantity.Should().Be(2);
    }

    [Fact]
    public async Task CreateOrder_MixedItems_ShouldCalculateTotalCorrectly()
    {
        // Arrange
        var regularProduct = await CreateRegularProduct();
        var variantProduct = await CreateProductWithVariants();
        var multiBuyProduct = await CreateProductWithMultiBuys();

        var multiBuy = multiBuyProduct.MultiBuys.First(mb => mb.Quantity == 3);

        var orderRequest = new CreateOrderDto
        {
            IdentityReference = "test_user_" + Guid.NewGuid(),
            ShippingName = "Alice Johnson",
            ShippingAddress = "321 Mixed St",
            ShippingCity = "Complex City",
            ShippingPostCode = "CC4 4ST",
            ShippingCountry = "United Kingdom",
            Items = new List<CreateOrderItemDto>
            {
                // Regular product
                new()
                {
                    ProductId = regularProduct.Id,
                    Quantity = 2
                },
                // Product with variant
                new()
                {
                    ProductId = variantProduct.Id,
                    Quantity = 1,
                    SelectedVariant = "Blue"
                },
                // Product with multi-buy
                new()
                {
                    ProductId = multiBuyProduct.Id,
                    ProductMultiBuyId = multiBuy.Id,
                    Quantity = 3
                }
            }
        };

        // Act
        var response = await _client.PostAsJsonAsync("/api/orders", orderRequest);

        // Assert
        response.StatusCode.Should().Be(HttpStatusCode.Created);

        var order = await response.Content.ReadFromJsonAsync<OrderDto>();
        order.Should().NotBeNull();
        order!.Items.Should().HaveCount(3);

        // Verify total calculation
        var expectedTotal = (regularProduct.Price * 2) +
                          variantProduct.Price +
                          multiBuy.Price;
        order.TotalAmount.Should().Be(expectedTotal);
    }

    [Fact]
    public async Task GetOrder_ShouldIncludeVariantAndMultiBuyInfo()
    {
        // Arrange
        var product = await CreateProductWithMultiBuysAndVariants();
        var multiBuy = product.MultiBuys.First();

        var orderRequest = new CreateOrderDto
        {
            IdentityReference = "test_user_" + Guid.NewGuid(),
            ShippingName = "Test User",
            ShippingAddress = "Test Address",
            ShippingCity = "Test City",
            ShippingPostCode = "TE1 1ST",
            ShippingCountry = "United Kingdom",
            Items = new List<CreateOrderItemDto>
            {
                new()
                {
                    ProductId = product.Id,
                    ProductMultiBuyId = multiBuy.Id,
                    Quantity = multiBuy.Quantity,
                    SelectedVariant = "Chocolate"
                }
            }
        };

        var createResponse = await _client.PostAsJsonAsync("/api/orders", orderRequest);
        var createdOrder = await createResponse.Content.ReadFromJsonAsync<OrderDto>();

        // Act
        var getResponse = await _client.GetAsync($"/api/orders/by-identity/{orderRequest.IdentityReference}/{createdOrder!.Id}");

        // Assert
        getResponse.StatusCode.Should().Be(HttpStatusCode.OK);

        var retrievedOrder = await getResponse.Content.ReadFromJsonAsync<OrderDto>();
        retrievedOrder.Should().NotBeNull();

        var item = retrievedOrder!.Items.First();
        item.ProductMultiBuyId.Should().Be(multiBuy.Id);
        item.SelectedVariant.Should().Be("Chocolate");
    }

    private async Task<ProductDto> CreateRegularProduct()
    {
        var category = await CreateTestCategory();

        var productDto = new CreateProductDto
        {
            Name = "Regular Product",
            Description = "A regular product without variants",
            Price = 15.00m,
            CategoryId = category.Id,
            Weight = 1.0m,
            WeightUnit = LittleShop.Enums.ProductWeightUnit.Kilograms
        };

        var response = await _client.PostAsJsonAsync("/api/admin/products", productDto);
        response.EnsureSuccessStatusCode();
        return (await response.Content.ReadFromJsonAsync<ProductDto>())!;
    }

    private async Task<ProductDto> CreateProductWithVariants()
    {
        var product = await CreateRegularProduct();

        // Add variants
        var variants = new[] { "Red", "Blue", "Green" };
        foreach (var variantName in variants)
        {
            var variantDto = new CreateProductVariantDto
            {
                ProductId = product.Id,
                Name = variantName,
                VariantType = "Color",
                StockLevel = 100
            };

            await _client.PostAsJsonAsync($"/api/admin/products/{product.Id}/variants", variantDto);
        }

        // Refresh product to get variants
        var response = await _client.GetAsync($"/api/catalog/products/{product.Id}");
        return (await response.Content.ReadFromJsonAsync<ProductDto>())!;
    }

    private async Task<ProductDto> CreateProductWithMultiBuys()
    {
        var product = await CreateRegularProduct();

        // Add multi-buys
        var multiBuys = new[]
        {
            new CreateProductMultiBuyDto
            {
                ProductId = product.Id,
                Name = "Twin Pack",
                Quantity = 2,
                Price = 25.00m
            },
            new CreateProductMultiBuyDto
            {
                ProductId = product.Id,
                Name = "Triple Pack",
                Quantity = 3,
                Price = 35.00m
            }
        };

        foreach (var multiBuyDto in multiBuys)
        {
            await _client.PostAsJsonAsync($"/api/admin/products/{product.Id}/multibuys", multiBuyDto);
        }

        // Refresh product to get multi-buys
        var response = await _client.GetAsync($"/api/catalog/products/{product.Id}");
        return (await response.Content.ReadFromJsonAsync<ProductDto>())!;
    }

    private async Task<ProductDto> CreateProductWithMultiBuysAndVariants()
    {
        var product = await CreateProductWithMultiBuys();

        // Add variants
        var variants = new[] { "Vanilla", "Chocolate", "Strawberry" };
        foreach (var variantName in variants)
        {
            var variantDto = new CreateProductVariantDto
            {
                ProductId = product.Id,
                Name = variantName,
                VariantType = "Flavor",
                StockLevel = 50
            };

            await _client.PostAsJsonAsync($"/api/admin/products/{product.Id}/variants", variantDto);
        }

        // Refresh product
        var response = await _client.GetAsync($"/api/catalog/products/{product.Id}");
        return (await response.Content.ReadFromJsonAsync<ProductDto>())!;
    }

    private async Task<CategoryDto> CreateTestCategory()
    {
        var categoryDto = new CreateCategoryDto
        {
            Name = "Test Category " + Guid.NewGuid(),
            Description = "Test category for integration tests"
        };

        var response = await _client.PostAsJsonAsync("/api/admin/categories", categoryDto);
        response.EnsureSuccessStatusCode();
        return (await response.Content.ReadFromJsonAsync<CategoryDto>())!;
    }
}