using MySqlConnector;
using Sony.Filtr.Database;
using Sony.Filtr.DistributedCaching;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace Sony.Filtr.PlaylistGeneration.Autocomplete
{
    public class DbArtistAutocompleteFactory : IAutocompleteFactory
    {
        private readonly DistributedCacheHandler _cacheHandler;

        public DbArtistAutocompleteFactory(DistributedCacheHandler distributedCacheHandler)
        {
            _cacheHandler = distributedCacheHandler;
        }

        public async Task<List<ArtistAutocompleteResult>> SearchArtistsAsync(string search, int count)
        {
            var cacheKey = "DbArtistAutocompleteFactory-1.0:" + search;
            var artists = _cacheHandler.Get(cacheKey) as List<ArtistAutocompleteResult>;
            if (artists == null)
            { 
                artists = await SearchArtistsInternalAsync(search, count);

                _cacheHandler.Put(cacheKey, artists, DateTime.Now.AddHours(1));
            }
            return artists;
        }

        private async Task<List<ArtistAutocompleteResult>> SearchArtistsInternalAsync(string search, int count)
        {
            List<ArtistAutocompleteResult> artists = new List<ArtistAutocompleteResult>();
            using (MySqlConnection conn = await DatabaseHandler.GetOpenReadOnlyConnectionAsync())
            {
                const string sql = "SELECT strArtistName, dblFamiliarity FROM tblAutocompleteArtistsEchoNest WHERE strArtistName LIKE @strSearch OR strAlias LIKE @strSearch ORDER BY dblFamiliarity DESC LIMIT @count";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@strSearch", search + "%");
                cmd.Parameters.AddWithValue("@count", count);

                using(var reader = await cmd.ExecuteReaderAsync())
                {
                    while (await reader.ReadAsync())
                    {
                        artists.Add(new ArtistAutocompleteResult()
                        {
                            Name = reader.GetString(0),
                            Score = reader.GetDouble(1)
                        });
                    }
                }
            }
            return artists;
        }
    }
}