using Core.DomainObjects;
using Core.DomainObjects.L10n;
using Core.Enumerations;
using DataProviders;
using DomainResults.Common;
using ExtensionMethods;
using WeatherForecast.Models;
using WeatherForecast.Models.Requests;

namespace WeatherForecast.Services {

  /// <summary>
  /// 
  /// </summary>
  public interface IShopItemService {
    
    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <param name="requestModel"></param>
    /// <returns></returns>
    (Guid?, IDomainResult) Post(Guid siteId, string sku, ShopItemRequestModel requestModel);

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <returns></returns>
    (ShopItemResponseModel?, IDomainResult) Get(Guid siteId, string sku);

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="slug"></param>
    /// <returns></returns>
    (ShopItemResponseModel?, IDomainResult) GetSlug(Guid siteId, string slug);

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <param name="requestData"></param>
    /// <returns></returns>
    (Guid?, IDomainResult) Update(Guid siteId, string sku, ShopItemRequestModel requestData);
    
    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <returns></returns>
    IDomainResult Delete(Guid siteId, string sku);
  }

  /// <summary>
  /// 
  /// </summary>
  public class ShopItemService : IShopItemService {

    private readonly ILogger<ShopItemService> _logger;
    private readonly IShopCatalogDataProvider _shopCatalogDataProvider;
    private readonly ICategoryDataProvider _categoryDataProvider;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="logger"></param>
    /// <param name="shopCatalogDataProvider"></param>
    /// <param name="categoryDataProvider"></param>
    public ShopItemService(
      ILogger<ShopItemService> logger,
      IShopCatalogDataProvider shopCatalogDataProvider,
      ICategoryDataProvider categoryDataProvider
    ) {
      _logger = logger;
      _shopCatalogDataProvider = shopCatalogDataProvider;
      _categoryDataProvider = categoryDataProvider;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <param name="requestModel"></param>
    /// <returns></returns>
    public (Guid?, IDomainResult) Post(Guid siteId, string sku, ShopItemRequestModel requestModel) {
      var (_, getResult) = _shopCatalogDataProvider.Get(siteId, sku);
      if (getResult.IsSuccess)
        return IDomainResult.Failed<Guid?>();

      var item = requestModel.ToDomainObject();

      item.SiteId = siteId;
      item.Sku = sku;

      // TODO: should be recovered from users by jwt
      item.Author = "fdc5aa50-ee68-4bae-a8e6-b8ae2c258f60".ToGuid();

      // TODO: should be placed to object storage
      item.Images = new List<Image>() {
        new Image {
          Src = "https://dummyimage.com/450x300/dee2e6/6c757d.jpg",
          L10n = new List<ImageL10n> {
            new ImageL10n {
            Locale = Locales.Us,
            Alt = "..."
            }
          }
        }
      };

      // TODO: default value shoud not be hardcoded by database id
      item.Categories ??= new List<Guid> { "e154e33f-3cc7-468d-bb66-e0390ddb9ae0".ToGuid() };

      var (id, insertResult) = _shopCatalogDataProvider.Insert(item);

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

      return IDomainResult.Success(id);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <returns></returns>
    public (ShopItemResponseModel?, IDomainResult) Get(Guid siteId, string sku) {
      var (item, result) = _shopCatalogDataProvider.Get(siteId, sku);

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

      var categories = new List<Category>();
      if (item.Categories != null) {
        foreach (var catId in item.Categories) {
          var (category, getCategoryResult) = _categoryDataProvider.Get(siteId, catId);
          if (!getCategoryResult.IsSuccess || category == null)
            return (null, getCategoryResult);

          categories.Add(category);
        }
      }

      return IDomainResult.Success(new ShopItemResponseModel(item, categories));
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="slug"></param>
    /// <returns></returns>
    public (ShopItemResponseModel?, IDomainResult) GetSlug(Guid siteId, string slug) {
      var (item, result) = _shopCatalogDataProvider.GetBySlug(siteId, slug);

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

      var locale = item.L10n.SingleOrDefault(x => x.Slug == slug)?.Locale ?? Locales.Us;

      var categories = new List<Category>();
      if (item.Categories != null) {
        foreach (var catId in item.Categories) {
          var (category, getCategoryResult) = _categoryDataProvider.Get(siteId, catId);
          if (!getCategoryResult.IsSuccess || category == null)
            return (null, getCategoryResult);

          categories.Add(category);
        }
      }

      return IDomainResult.Success(new ShopItemResponseModel(item, categories, locale));
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <param name="requestData"></param>
    /// <returns></returns>
    public (Guid?, IDomainResult) Update(Guid siteId, string sku, ShopItemRequestModel requestData) {
      var (item, getResult) = _shopCatalogDataProvider.Get(siteId, sku);
      if (!getResult.IsSuccess || item == null)
        return (null, getResult);

      // construct domain object from model
      var newItem = requestData.ToDomainObject();
      newItem.Id = item.Id;
      newItem.SiteId = siteId;
      newItem.Sku = sku;
      newItem.Created = item.Created;
      newItem.Author = item.Author;

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

      return IDomainResult.Success(item.Id);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="sku"></param>
    /// <returns></returns>
    public IDomainResult Delete(Guid siteId, string sku) {
      var (item, getResult) = _shopCatalogDataProvider.Get(siteId, sku);
      if (!getResult.IsSuccess || item == null)
        return getResult;

      var result = _shopCatalogDataProvider.Delete(item.Id);
      if (!result.IsSuccess)
        return result;

      return IDomainResult.Success();
    }

  }
}