using DomainResults.Common;

using DataProviders;

using Core.Abstractions;
using Core.DomainObjects;
using Core.Enumerations;

using WeatherForecast.Models.Responses;
using DataProviders.Collections;
using Core.DomainObjects.Documents;

namespace WeatherForecast.Services {

  /// <summary>
  /// 
  /// </summary>
  public interface IBlogItemsService {

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="category"></param>
    /// <param name="currentPage"></param>
    /// <param name="itemsPerPage"></param>
    /// <param name="locale"></param>
    /// <param name="searchText"></param>
    /// <returns></returns>
    (BlogItemsResponseModel?, IDomainResult) Get(Guid siteId, Guid? category, int currentPage, int itemsPerPage, string? locale, string? searchText);
    
    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <returns></returns>
    IDomainResult Delete(Guid siteId);
  }

  /// <summary>
  /// 
  /// </summary>
  public class BlogItemsService : IBlogItemsService {

    private readonly ILogger<BlogItemsService> _logger;
    private readonly IBlogCatalogDataProvider _blogCatalogDataProvider;
    private readonly ICategoryDataProvider _categoryDataProvider;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="logger"></param>
    /// <param name="blogCatalogDataProvider"></param>
    /// <param name="categoryDataProvider"></param>
    public BlogItemsService(
      ILogger<BlogItemsService> logger,
      IBlogCatalogDataProvider blogCatalogDataProvider,
      ICategoryDataProvider categoryDataProvider
    ) {
      _logger = logger;
      _blogCatalogDataProvider = blogCatalogDataProvider;
      _categoryDataProvider = categoryDataProvider;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <param name="category"></param>
    /// <param name="currentPage"></param>
    /// <param name="itemsPerPage"></param>
    /// <param name="locale"></param>
    /// <param name="searchText"></param>
    /// <returns></returns>
    public (BlogItemsResponseModel?, IDomainResult) Get(Guid siteId, Guid? category, int currentPage, int itemsPerPage, string? locale, string? searchText) {
      try {
        var (items, result) = _blogCatalogDataProvider.GetAll(siteId, currentPage > 0 ? ((currentPage - 1) * itemsPerPage) : 0, itemsPerPage);
        if (!result.IsSuccess || items == null)
          return (null, result);

        var blogItems = new List<BlogItemResponseModel>();
        foreach (var item in items) {
          var categories = new List<Category>();

          if (item.Categories != null) {
            foreach (var catId in item.Categories) {
              var (cat, getCategoryResult) = _categoryDataProvider.Get(siteId, catId);
              if (!getCategoryResult.IsSuccess || cat == null)
                return (null, getCategoryResult);

              categories.Add(cat);
            }
          }

          if (locale != null)
            blogItems.Add(new BlogItemResponseModel(item, categories, Enumeration.FromDisplayName<Locales>(locale) ?? Locales.Us));
          else
            blogItems.Add(new BlogItemResponseModel(item, categories));
        }

        return blogItems.Count > 0
          ? IDomainResult.Success(new BlogItemsResponseModel(currentPage, 0, blogItems))
          : IDomainResult.NotFound<BlogItemsResponseModel?>();
      }
      catch (Exception ex) {
        _logger.LogError(ex, "Unhandled exception");
        return IDomainResult.Failed<BlogItemsResponseModel?>(ex.Message);
      }
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="siteId"></param>
    /// <returns></returns>
    public IDomainResult Delete(Guid siteId) {
      try {
        return _blogCatalogDataProvider.DeleteAll(siteId);
      }
      catch (Exception ex) {
        _logger.LogError(ex, "Unhandled exception");
        return IDomainResult.Failed(ex.Message);
      }
    }
  }
}