// src/Webshop.Application/Services/Customers/OrderService.cs
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Webshop.Application;
using Webshop.Application.DTOs.Customers;
using Webshop.Application.DTOs.Orders;
using Webshop.Domain.Entities;
using Webshop.Domain.Enums;
using Webshop.Domain.Interfaces;
using Webshop.Infrastructure.Data;

namespace Webshop.Application.Services.Customers
{
    public class OrderService : IOrderService
    {
        private readonly ApplicationDbContext _context;
        private readonly ICustomerRepository _customerRepository;

        public OrderService(ApplicationDbContext context, ICustomerRepository customerRepository)
        {
            _context = context;
            _customerRepository = customerRepository;
        }

        public async Task<ServiceResult<IEnumerable<OrderSummaryDto>>> GetMyOrdersAsync(string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null)
            {
                return ServiceResult.Ok<IEnumerable<OrderSummaryDto>>(new List<OrderSummaryDto>());
            }

            var orders = await _context.Orders
                .Where(o => o.CustomerId == customer.Id)
                .OrderByDescending(o => o.OrderDate)
                // +++ KORREKTUR: Verknüpfte Entitäten explizit laden +++
                .Include(o => o.ShippingMethodInfo)
                .Include(o => o.PaymentMethodInfo)
                .ToListAsync();

            var dtos = orders.Select(o => new OrderSummaryDto
            {
                Id = o.Id,
                OrderNumber = o.OrderNumber,
                OrderDate = o.OrderDate,
                CustomerName = $"{customer.FirstName} {customer.LastName}",
                TotalAmount = o.OrderTotal,
                Status = Enum.TryParse<OrderStatus>(o.OrderStatus, true, out var os) ? os : OrderStatus.Pending,
                PaymentStatus = Enum.TryParse<PaymentStatus>(o.PaymentStatus, true, out var ps) ? ps : PaymentStatus.Pending,
                // +++ KORREKTUR: Daten aus den geladenen Entitäten zuweisen +++
                ShippingMethodName = o.ShippingMethodInfo?.Name,
                PaymentMethodName = o.PaymentMethodInfo?.Name
            }).ToList();

            return ServiceResult.Ok<IEnumerable<OrderSummaryDto>>(dtos);
        }

        public async Task<ServiceResult<OrderDetailDto>> GetMyOrderByIdAsync(Guid orderId, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null)
            {
                return ServiceResult.Fail<OrderDetailDto>(ServiceResultType.Unauthorized, "Kundenprofil nicht gefunden.");
            }

            var order = await _context.Orders
                .Include(o => o.BillingAddress)
                .Include(o => o.ShippingAddress)
                .Include(o => o.OrderItems)
                // +++ KORREKTUR: Verknüpfte Entitäten explizit laden +++
                .Include(o => o.ShippingMethodInfo)
                .Include(o => o.PaymentMethodInfo)
                .FirstOrDefaultAsync(o => o.Id == orderId);

            if (order == null)
            {
                return ServiceResult.Fail<OrderDetailDto>(ServiceResultType.NotFound, $"Bestellung mit ID '{orderId}' nicht gefunden.");
            }

            if (order.CustomerId != customer.Id)
            {
                return ServiceResult.Fail<OrderDetailDto>(ServiceResultType.Forbidden, "Zugriff auf diese Bestellung verweigert.");
            }

            return ServiceResult.Ok(MapToOrderDetailDto(order));
        }

        private OrderDetailDto MapToOrderDetailDto(Order order)
        {
            // Die `MapToDto`-Methode muss die neuen Daten ebenfalls verwenden.
            // Die `PaymentMethod`-Eigenschaft in `OrderDetailDto` scheint den Namen zu erwarten.
            return new OrderDetailDto
            {
                Id = order.Id,
                OrderNumber = order.OrderNumber,
                OrderDate = order.OrderDate,
                CustomerId = order.CustomerId,
                Status = Enum.TryParse<OrderStatus>(order.OrderStatus, true, out var os) ? os : OrderStatus.Pending,
                TotalAmount = order.OrderTotal,
                ShippingAddress = new AddressDto
                {
                    Id = order.ShippingAddress.Id,
                    Street = order.ShippingAddress.Street,
                    HouseNumber = order.ShippingAddress.HouseNumber,
                    City = order.ShippingAddress.City,
                    PostalCode = order.ShippingAddress.PostalCode,
                    Country = order.ShippingAddress.Country,
                    Type = order.ShippingAddress.Type,
                    FirstName = order.ShippingAddress.FirstName,
                    LastName = order.ShippingAddress.LastName
                },
                BillingAddress = new AddressDto
                {
                    Id = order.BillingAddress.Id,
                    Street = order.BillingAddress.Street,
                    HouseNumber = order.BillingAddress.HouseNumber,
                    City = order.BillingAddress.City,
                    PostalCode = order.BillingAddress.PostalCode,
                    Country = order.BillingAddress.Country,
                    Type = order.BillingAddress.Type,
                    FirstName = order.BillingAddress.FirstName,
                    LastName = order.BillingAddress.LastName
                },
                // +++ KORREKTUR: Den Namen aus der geladenen Entität verwenden +++
                PaymentMethod = order.PaymentMethodInfo?.Name,
                PaymentStatus = Enum.TryParse<PaymentStatus>(order.PaymentStatus, true, out var ps) ? ps : PaymentStatus.Pending,
                ShippingTrackingNumber = order.ShippingTrackingNumber,
                ShippedDate = order.ShippedDate,
                DeliveredDate = order.DeliveredDate,
                OrderItems = order.OrderItems.Select(oi => new OrderItemDto
                {
                    Id = oi.Id,
                    ProductId = oi.ProductId,
                    ProductVariantId = oi.ProductVariantId,
                    ProductName = oi.ProductName,
                    ProductSKU = oi.ProductSKU,
                    Quantity = oi.Quantity,
                    UnitPrice = oi.UnitPrice,
                    TotalPrice = oi.TotalPrice
                }).ToList()
            };
        }
    }
}