using Raven.Client.Documents;
using Raven.Client.Documents.Linq;
using Raven.Client.Documents.Session;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using zero.Core.Collections;
using zero.Core.Database.Indexes;
using zero.Core.Entities;
using zero.Core.Extensions;

namespace zero.Core.Api
{
  public class SpacesApi : BackofficeApi, ISpacesApi
  {
    protected IPermissionsApi PermissionsApi { get; private set; }


    public SpacesApi(ICollectionContext store, IPermissionsApi permissionsApi) : base(store)
    {
      PermissionsApi = permissionsApi;
    }


    /// <inheritdoc />
    public Space GetByAlias(string alias)
    {
      return GetAll().FirstOrDefault(x => x.Alias.Equals(alias, StringComparison.InvariantCultureIgnoreCase));
    }


    /// <inheritdoc />
    public Space GetBy<T>() where T : SpaceContent
    {
      Type type = typeof(T);
      return GetAll().FirstOrDefault(x => x.Type == type);
    }


    /// <inheritdoc />
    public IReadOnlyCollection<Space> GetAll()
    {
      return Context.Options.Spaces.GetAllItems();
    }


    /// <inheritdoc />
    public async Task<SpaceContent> GetItem(string alias, string id = null)
    {
      Space space = GetByAlias(alias);
      return await Session.Query<SpaceContent>()
        .Where(x => x.SpaceAlias == space.Alias)
        .WhereIf(x => x.Id == id, !id.IsNullOrEmpty())
        .FirstOrDefaultAsync();
    }


    /// <inheritdoc />
    public async Task<T> GetItem<T>(string id = null) where T : SpaceContent
    {
      Space space = GetBy<T>();

      return await Session.Query<T>()
        .Where(x => x.SpaceAlias == space.Alias)
        .WhereIf(x => x.Id == id, !id.IsNullOrEmpty())
        .FirstOrDefaultAsync();
    }


    /// <inheritdoc />
    public async Task<Dictionary<string, T>> GetItems<T>(params string[] ids) where T : SpaceContent
    {
      Space space = GetBy<T>();

      ids = ids.Distinct().ToArray();

      Dictionary<string, T> models = await Session.LoadAsync<T>(ids);
      Dictionary<string, T> result = new Dictionary<string, T>();

      foreach (string id in ids)
      {
        models.TryGetValue(id, out T model);
        result.Add(id, model);
      }

      return result;
    }


    /// <inheritdoc />
    public async Task<ListResult<SpaceContent>> GetListByQuery(string alias, ListQuery<SpaceContent> query)
    {
      query.SearchSelector = item => item.Name;

      return await Session.Query<SpaceContent, zero_Spaces>()
        .Where(x => x.SpaceAlias == alias)
        .ToQueriedListAsync(query);
    }


    /// <inheritdoc />
    public async Task<ListResult<T>> GetListByQuery<T>(string alias, ListQuery<T> query) where T : SpaceContent
    {
      query.SearchSelector = item => item.Name;

      return await Session.Query<T>()
        .Where(x => x.SpaceAlias == alias)
        .ToQueriedListAsync(query);
    }


    /// <inheritdoc />
    public async Task<ListResult<T>> GetListByQuery<T>(ListQuery<T> query) where T : SpaceContent
    {
      Space space = GetBy<T>();
      query.SearchSelector = item => item.Name;

      return await Session.Query<T>()
        .Where(x => x.SpaceAlias == space.Alias)
        .ToQueriedListAsync(query);
    }


    /// <inheritdoc />
    public async Task<EntityResult<SpaceContent>> Save(SpaceContent model)
    {
      return await SaveModel(model, null);
    }


    /// <inheritdoc />
    public async Task<EntityResult<SpaceContent>> Delete(string id)
    {
      return await DeleteById<SpaceContent>(id);
    }
  }


  public interface ISpacesApi
  {
    /// <summary>
    /// Returns a space by the defined alias
    /// </summary>
    Space GetByAlias(string alias);

    /// <summary>
    /// Returns a space by a defined generic
    /// </summary>
    Space GetBy<T>() where T : SpaceContent;

    /// <summary>
    /// Get all spaces
    /// </summary>
    IReadOnlyCollection<Space> GetAll();

    /// <summary>
    /// Get editor item for a space
    /// </summary>
    Task<SpaceContent> GetItem(string alias, string id = null);

    /// <summary>
    /// Get editor item for a space
    /// </summary>
    Task<T> GetItem<T>(string id = null) where T : SpaceContent;

    /// <summary>
    /// Get editor items for a space
    /// </summary>
    Task<Dictionary<string, T>> GetItems<T>(params string[] ids) where T : SpaceContent;

    /// <summary>
    /// Get all list items for a space (with query)
    /// </summary>
    Task<ListResult<SpaceContent>> GetListByQuery(string alias, ListQuery<SpaceContent> query);

    /// <summary>
    /// Get all list items for a space (with query)
    /// </summary>
    Task<ListResult<T>> GetListByQuery<T>(string alias, ListQuery<T> query) where T : SpaceContent;

    /// <summary>
    /// Get all list items for a space (with query)
    /// </summary>
    Task<ListResult<T>> GetListByQuery<T>(ListQuery<T> query) where T : SpaceContent;

    /// <summary>
    /// Saves a content item in a space
    /// </summary>
    Task<EntityResult<SpaceContent>> Save(SpaceContent model);

    /// <summary>
    /// Deletes a space content item
    /// </summary>
    Task<EntityResult<SpaceContent>> Delete(string id);
  }
}