// src/Webshop.Application/Services/Customers/AddressService.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Webshop.Application;
using Webshop.Application.DTOs.Customers;
using Webshop.Domain.Entities;
using Webshop.Domain.Interfaces;

namespace Webshop.Application.Services.Customers
{
    public class AddressService : IAddressService
    {
        private readonly IAddressRepository _addressRepository;
        private readonly ICustomerRepository _customerRepository;

        public AddressService(IAddressRepository addressRepository, ICustomerRepository customerRepository)
        {
            _addressRepository = addressRepository;
            _customerRepository = customerRepository;
        }

        public async Task<ServiceResult<IEnumerable<AddressDto>>> GetMyAddressesAsync(string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null)
            {
                // If the customer profile doesn't exist for a valid user, return an empty list.
                return ServiceResult.Ok<IEnumerable<AddressDto>>(new List<AddressDto>());
            }

            var addresses = await _addressRepository.GetAllForCustomerAsync(customer.Id);
            return ServiceResult.Ok(addresses.Select(MapToDto));
        }

        public async Task<ServiceResult<AddressDto>> GetMyAddressByIdAsync(Guid addressId, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null)
            {
                return ServiceResult.Fail<AddressDto>(ServiceResultType.NotFound, "Kundenprofil nicht gefunden.");
            }

            var address = await _addressRepository.GetByIdAsync(addressId);
            if (address == null)
            {
                return ServiceResult.Fail<AddressDto>(ServiceResultType.NotFound, $"Adresse mit ID '{addressId}' nicht gefunden.");
            }

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

            return ServiceResult.Ok(MapToDto(address));
        }

        public async Task<ServiceResult<AddressDto>> CreateAddressAsync(CreateAddressDto addressDto, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null)
            {
                return ServiceResult.Fail<AddressDto>(ServiceResultType.NotFound, "Kundenprofil nicht gefunden.");
            }

            var newAddress = new Address
            {
                CustomerId = customer.Id,
                FirstName = addressDto.FirstName ?? customer.FirstName,
                LastName = addressDto.LastName ?? customer.LastName,
                Street = addressDto.Street,
                HouseNumber = addressDto.HouseNumber,
                City = addressDto.City,
                PostalCode = addressDto.PostalCode,
                Country = addressDto.Country,
                Type = addressDto.Type
            };

            await _addressRepository.AddAsync(newAddress);
            return ServiceResult.Ok(MapToDto(newAddress));
        }

        public async Task<ServiceResult> UpdateAddressAsync(UpdateAddressDto addressDto, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Kundenprofil nicht gefunden.");

            var address = await _addressRepository.GetByIdAsync(addressDto.Id);
            if (address == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Adresse nicht gefunden.");
            if (address.CustomerId != customer.Id) return ServiceResult.Fail(ServiceResultType.Forbidden, "Zugriff auf diese Adresse verweigert.");

            address.FirstName = addressDto.FirstName;
            address.LastName = addressDto.LastName;
            address.Street = addressDto.Street;
            address.HouseNumber = addressDto.HouseNumber;
            address.City = addressDto.City;
            address.PostalCode = addressDto.PostalCode;
            address.Country = addressDto.Country;
            address.Type = addressDto.Type;

            await _addressRepository.UpdateAsync(address);
            return ServiceResult.Ok();
        }

        public async Task<ServiceResult> DeleteAddressAsync(Guid addressId, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Kundenprofil nicht gefunden.");

            var address = await _addressRepository.GetByIdAsync(addressId);
            if (address == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Adresse nicht gefunden.");
            if (address.CustomerId != customer.Id) return ServiceResult.Fail(ServiceResultType.Forbidden, "Zugriff auf diese Adresse verweigert.");

            await _addressRepository.DeleteAsync(addressId);
            return ServiceResult.Ok();
        }

        public async Task<ServiceResult> SetDefaultShippingAddressAsync(Guid addressId, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Kundenprofil nicht gefunden.");

            var address = await _addressRepository.GetByIdAsync(addressId);
            if (address == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Adresse nicht gefunden.");
            if (address.CustomerId != customer.Id) return ServiceResult.Fail(ServiceResultType.Forbidden, "Zugriff auf diese Adresse verweigert.");

            customer.DefaultShippingAddressId = addressId;
            await _customerRepository.UpdateAsync(customer);
            return ServiceResult.Ok();
        }

        public async Task<ServiceResult> SetDefaultBillingAddressAsync(Guid addressId, string userId)
        {
            var customer = await _customerRepository.GetByUserIdAsync(userId);
            if (customer == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Kundenprofil nicht gefunden.");

            var address = await _addressRepository.GetByIdAsync(addressId);
            if (address == null) return ServiceResult.Fail(ServiceResultType.NotFound, "Adresse nicht gefunden.");
            if (address.CustomerId != customer.Id) return ServiceResult.Fail(ServiceResultType.Forbidden, "Zugriff auf diese Adresse verweigert.");

            customer.DefaultBillingAddressId = addressId;
            await _customerRepository.UpdateAsync(customer);
            return ServiceResult.Ok();
        }

        private AddressDto MapToDto(Address address)
        {
            return new AddressDto
            {
                Id = address.Id,
                FirstName = address.FirstName,
                LastName = address.LastName,
                Street = address.Street,
                HouseNumber = address.HouseNumber,
                City = address.City,
                PostalCode = address.PostalCode,
                Country = address.Country,
                Type = address.Type
            };
        }
    }
}