// src/Webshop.Application/Services/Admin/AdminOrderService.cs
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.Enums;
using Webshop.Domain.Interfaces;

namespace Webshop.Application.Services.Admin
{
    public class AdminOrderService : IAdminOrderService
    {
        private readonly IOrderRepository _orderRepository;

        public AdminOrderService(IOrderRepository orderRepository)
        {
            _orderRepository = orderRepository;
        }

        public async Task<ServiceResult<IEnumerable<OrderSummaryDto>>> GetAllOrdersAsync()
        {
            var orders = await _orderRepository.GetAllAsync();
            var dtos = orders.Select(o => new OrderSummaryDto
            {
                Id = o.Id,
                OrderNumber = o.OrderNumber,
                OrderDate = o.OrderDate,
                CustomerName = o.Customer != null ? $"{o.Customer.FirstName} {o.Customer.LastName}" : o.GuestEmail ?? "Gastbestellung",
                TotalAmount = o.OrderTotal,
                Status = Enum.TryParse<OrderStatus>(o.OrderStatus, true, out var orderStatus) ? orderStatus : OrderStatus.Pending,
                PaymentStatus = Enum.TryParse<PaymentStatus>(o.PaymentStatus, true, out var paymentStatus) ? paymentStatus : PaymentStatus.Pending
            }).ToList();

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

        public async Task<ServiceResult<OrderDetailDto>> GetOrderByIdAsync(Guid id)
        {
            var order = await _orderRepository.GetByIdAsync(id);
            if (order == null)
            {
                return ServiceResult.Fail<OrderDetailDto>(ServiceResultType.NotFound, $"Bestellung mit ID '{id}' nicht gefunden.");
            }

            var orderDetailDto = new OrderDetailDto
            {
                Id = order.Id,
                OrderNumber = order.OrderNumber,
                OrderDate = order.OrderDate,
                CustomerId = order.CustomerId,
                Status = Enum.TryParse<OrderStatus>(order.OrderStatus, true, out var orderStatus) ? orderStatus : 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
                },
                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
                },
                PaymentMethod = order.PaymentMethod,
                PaymentStatus = Enum.TryParse<PaymentStatus>(order.PaymentStatus, true, out var paymentStatus) ? paymentStatus : PaymentStatus.Pending,
                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()
            };

            return ServiceResult.Ok(orderDetailDto);
        }

        public async Task<ServiceResult> UpdateOrderStatusAsync(Guid id, OrderStatus newStatus)
        {
            if (!Enum.IsDefined(typeof(OrderStatus), newStatus))
            {
                return ServiceResult.Fail(ServiceResultType.InvalidInput, $"Der Status '{newStatus}' ist ungültig.");
            }

            var order = await _orderRepository.GetByIdAsync(id);
            if (order == null)
            {
                return ServiceResult.Fail(ServiceResultType.NotFound, $"Bestellung mit ID '{id}' nicht gefunden.");
            }

            order.OrderStatus = newStatus.ToString();

            // Hier könnte zusätzliche Logik stehen (z.B. Tracking-Nummer verlangen)
            if (newStatus == OrderStatus.Shipped && string.IsNullOrEmpty(order.ShippingTrackingNumber))
            {
                // return ServiceResult.Fail(ServiceResultType.InvalidInput, "Für den Status 'Versandt' wird eine Tracking-Nummer benötigt.");
            }

            await _orderRepository.UpdateAsync(order);
            return ServiceResult.Ok();
        }
    }
}