using DataProviders;
using DomainResults.Common;

using WeatherForecast.Models.Requests;
using WeatherForecast.Models.Responses;

namespace WeatherForecast.Services {

  public interface IShopCartItemService {
    (Guid?, IDomainResult) Post(Guid siteId, Guid userId, string sku, PostShopCartItemRequestModel requestModel);
    (GetShopCartItemResponseModel?, IDomainResult) Get(Guid siteId, Guid userId, string sku);
    (Guid?, IDomainResult) Update(Guid siteId, Guid userId, string sku, PutShopCartItemRequestModel requestData);
    IDomainResult Delete(Guid siteId, Guid userId, string sku);
  }

  public class ShopCartItemService : IShopCartItemService {

    ILogger<ShopCartItemService> _logger;
    IShopCartDataProvider _shopCartDataProvider;

    public ShopCartItemService(
      ILogger<ShopCartItemService> logger,
      IShopCartDataProvider shopCartDataprovider
    ) {
      _logger = logger;
      _shopCartDataProvider = shopCartDataprovider;
    }

    public (Guid?, IDomainResult) Post(Guid siteId, Guid userId, string sku, PostShopCartItemRequestModel requestModel) {
      var (_, getResult) = _shopCartDataProvider.Get(siteId, userId, sku);
      if (getResult.IsSuccess)
        return IDomainResult.Failed<Guid?>();

      var obj = requestModel.ToDomainObject();

      obj.SiteId = siteId;
      obj.UserId = userId;
      obj.Sku = sku;

      var (id, insertResult) = _shopCartDataProvider.Insert(obj);

      if (!insertResult.IsSuccess)
        return IDomainResult.Failed<Guid?>();

      return IDomainResult.Success(id);
    }

    public (GetShopCartItemResponseModel?, IDomainResult) Get(Guid siteId, Guid userId, string sku) {
      var (item, result) = _shopCartDataProvider.Get(siteId, userId, sku);

      if (!result.IsSuccess || item == null)
        return (null, result);

      return IDomainResult.Success(new GetShopCartItemResponseModel(item));
    }

    public (Guid?, IDomainResult) Update(Guid siteId, Guid userId, string sku, PutShopCartItemRequestModel requestData) {
      var (item, getResult) = _shopCartDataProvider.Get(siteId, userId, sku);
      if (!getResult.IsSuccess || item == null)
        return (null, getResult);

      var newShopCart = requestData.ApplyTo(item);

      if (!item.Equals(newShopCart)) {
        var (id, updateResult) = _shopCartDataProvider.Update(item);
        if (!updateResult.IsSuccess || id == null)
          return (null, updateResult);
      }

      return IDomainResult.Success(item.Id);
    }

    public IDomainResult Delete(Guid siteId, Guid userId, string sku) {
      var result = _shopCartDataProvider.Delete(siteId, userId, sku);
      if (!result.IsSuccess)
        return result;

      return IDomainResult.Success();
    }
  }
}