using Raven.Client.Documents;
using System;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using zero.Core.Database;
using zero.Core.Entities;
using zero.Core.Models;
using zero.Core.Renderer;

namespace zero.Core.Options
{
  public class SearchOptions : ZeroBackofficeCollection<SearchIndexMap>, IZeroCollectionOptions
  {
    public bool IsEnabled { get; set; }


    public SearchOptions()
    {
      IsEnabled = true;
      Map<Page>().Display((x, res, opts) =>
      {
        PageType pageType = opts.Pages.GetByAlias(x.PageTypeAlias);
        if (pageType != null)
        {
          res.Icon = pageType.Icon;
        }
        res.Url = "/pages/edit/" + x.Id;
      });
      Map<MediaFolder>("fth-image");
    }


    public SearchIndexMap<T> Map<T>(string icon = null) where T : ZeroEntity, new()
    {
      SearchIndexMap<T> map = new(icon);
      Items.Add(map);
      return map;
    }
  }


  public class SearchIndexMap
  {
    internal Type Type;
    internal string _Icon;
    protected string _group;
    protected string[] _fields;
    protected Func<ZeroEntity, SearchResult, IZeroOptions, Task> _modify;

    const string mapTemplate = @"map('{collection}', function (x) { 
                                  return { 
                                    Id: x.Id,
                                    Group: '{group}',
                                    Name: x.Name,
                                    IsActive: x.IsActive,
                                    Fields: [{fields}]
                                  };
                                });";

    internal SearchIndexMap(Type type, string icon = null)
    {
      Type = type;
      _group = "__TODO";
      _Icon = icon;
    }

    internal string BuildInstruction(IDocumentStore store)
    {
      return TokenReplacement.Apply(mapTemplate, new()
      {
        { "collection", store.Conventions.GetCollectionName(Type) },
        { "group", _group },
        { "fields", BuildFieldArray(_fields) }
      });
    }

    internal string BuildFieldArray(string[] fields)
    {
      if (fields == null || !fields.Any())
      {
        return String.Empty;
      }

      return "x." + String.Join(", x.", fields);
    }

    internal bool CanModify(Type type)
    {
      return Type.IsAssignableFrom(type);
    }

    internal async Task Modify(ZeroEntity entity, SearchResult result, IZeroOptions options)
    {
      if (_modify != null)
      {
        await _modify(entity, result, options);
      }
    }
  }


  public class SearchIndexMap<T> : SearchIndexMap where T : ZeroEntity
  {
    internal SearchIndexMap(string icon = null) : base(typeof(T), icon) {}

    public SearchIndexMap<T> Icon(string icon)
    {
      _Icon = icon;
      return this;
    }

    public SearchIndexMap<T> Display(Action<T, SearchResult> modify = null)
    {
      _modify = (x, res, opts) =>
      {
        modify?.Invoke(x as T, res);
        return Task.CompletedTask;
      };
      return this;
    }

    public SearchIndexMap<T> Display(Func<T, SearchResult, Task> modify = null)
    {
      _modify = (x, res, opts) => modify?.Invoke(x as T, res);
      return this;
    }

    public SearchIndexMap<T> Display(Action<T, SearchResult, IZeroOptions> modify = null)
    {
      _modify = (x, res, opts) =>
      {
        modify?.Invoke(x as T, res, opts);
        return Task.CompletedTask;
      };
      return this;
    }

    public SearchIndexMap<T> Display(Func<T, SearchResult, IZeroOptions, Task> modify = null)
    {
      _modify = (x, res, opts) => modify?.Invoke(x as T, res, opts);
      return this;
    }

    public SearchIndexMap<T> Fields(params string[] fieldNames)
    {
      _fields = fieldNames;
      return this;
    }
  }
}