using System;
using System.Collections.Generic;
using System.Globalization;

using MySql.Data.MySqlClient;

using Icarus.Models;

namespace Icarus.Database.Repositories
{
    public class GenreRepository : BaseRepository
    {
        #region Fields
        #endregion


        #region Properties
        #endregion


        #region Constructors
        public GenreRepository(string connectionString)
        {
            _connectionString = connectionString;
        }
        #endregion


        #region Methods
        public List<Genre> GetGenresWithoutCount()
        {
            _logger.Info("Retrieving all genre records without song counts");

            var genres = new List<Genre>();

            if (AnyGenre())
            {

                try
                {
                    using (var conn = GetConnection())
                    {
                        conn.Open();

                        var query = "SELECT * FROM Genre";

                        using (var cmd = new MySqlCommand(query, conn))
                            using (var reader = cmd.ExecuteReader())
                                genres = ParseData(reader);
                    }
                }
                catch (Exception ex)
                {
                    var msg = ex.Message;
                    _logger.Error(msg, "An error occurred");
                }
            }

            return genres;
        }
        public List<Genre> GetGenres()
        {
            _logger.Info("Retrieving Genre records");

            var genres = new List<Genre>();

            if (AnyGenre())
            {

                try
                {
                    using (var conn = GetConnection())
                    {
                        conn.Open();

                        var query = "SELECT gnr.*, COUNT(*) AS SongCount FROM Genre " + 
                            "gnr LEFT JOIN Song sng ON gnr.GenreId=sng.GenreId " +
                            "GROUP BY gnr.GenreId";

                        using (var cmd = new MySqlCommand(query, conn))
                            using (var reader = cmd.ExecuteReader())
                                genres = ParseData(reader);
                    }
                }
                catch (Exception ex)
                {
                    var msg = ex.Message;
                    _logger.Error(msg, "An error occurred");
                }
            }

            return genres;
        }

        public Genre GetGenre(Genre genre)
        {
            _logger.Info("Retrieving Genre record");

            if (DoesGenreExist(genre))
            {
                try
                {
                    using (var conn = GetConnection())
                    {
                        conn.Open();

                        var query = "SELECT gnr.*, COUNT(*) AS SongCount FROM Genre " +
                            "gnr LEFT JOIN Song sng ON gnr.GenreId=sng.GenreId  " +
                               "WHERE gnr.GenreId=@GenreId";

                        using (var cmd = new MySqlCommand(query, conn))
                        {
                            cmd.Parameters.AddWithValue("@GenreId", genre.GenreId);

                            using (var reader = cmd.ExecuteReader())
                                genre = ParseSingleData(reader);
                        }
                    }
                }
                catch (Exception ex)
                {
                    var msg = ex.Message;
                    _logger.Error(msg, "An error occurred");
                }
            }

            return genre;
        }
        public Genre GetGenre(Song song)
        {
            _logger.Info("Retrieving Genre record");

            var genre = new Genre();

            if (DoesGenreExist(song))
            {
                try
                {
                    using (var conn = GetConnection())
                    {
                        conn.Open();

                        var query = "SELECT gnr.*, 0 AS SongCount FROM Genre " +
                            "gnr WHERE gnr.GenreName=@GenreName";

                        using (var cmd = new MySqlCommand(query, conn))
                        {
                            cmd.Parameters.AddWithValue("@GenreName", song.Genre);
                            _logger.Info($"Song genre:\n\n\n {song.Genre}");

                            using (var reader = cmd.ExecuteReader())
                                genre = ParseSingleData(reader);
                        }
                    }
                }
                catch (Exception ex)
                {
                    var msg = ex.Message;
                    _logger.Error(msg, "An error occurred");
                }
            }

            return genre;
        }
        public Genre GetGenre(Song song, bool retrieveCount)
        {
            _logger.Info("Retrieving Genre record");

            var genre = new Genre();

            if (DoesGenreExist(song))
            {
                try
                {
                    using (var conn = GetConnection())
                    {
                        conn.Open();

                        var query = string.Empty;

                        if (retrieveCount)
                            query = "SELECT gnr.*, COUNT(*) AS SongCount FROM Genre gnr " +
                                "LEFT JOIN Song sng ON gnr.GenreId=sng.GenreId " +
                                "WHERE gnr.GenreName=@GenreName GROUP BY gnr.GenreId " +
                                "LIMIT 1";
                        else
                            query = "SELECT gnr.*, 0 AS SongCount FROM Genre gnr " +
                                "WHERE gnr.GenreName=@GenreName LIMIT 1";

                        using (var cmd = new MySqlCommand(query, conn))
                        {
                            cmd.Parameters.AddWithValue("@GenreName", song.Genre);
                            _logger.Info($"Song genre:\n\n\n {song.Genre}");

                            using (var reader = cmd.ExecuteReader())
                                genre = ParseSingleData(reader);
                        }
                    }
                }
                catch (Exception ex)
                {
                    var msg = ex.Message;
                    _logger.Error(msg, "An error occurred");
                }
            }

            return genre;
        }

        public bool DoesGenreExist(Genre genre)
        {
            _logger.Info("Checking to see if Genre record exists");

            try
            {
                using (var conn = GetConnection())
                {
                    conn.Open();

                    var query = "SELECT gnr.*, 0 AS SongCount FROM Genre gnr WHERE " +
                        "gnr.GenreId=@GenreId";

                    using (var cmd = new MySqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@GenreId", genre.GenreId);

                        using (var reader = cmd.ExecuteReader())
                        {
                            genre = ParseSingleData(reader);
                            var genreName = genre.GenreName;

                            if (!string.IsNullOrEmpty(genreName))
                            {
                                _logger.Info("Genre exists");

                                return true;
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
                _logger.Error(msg, "An error occurred");
            }

            _logger.Info("Genre does not exist");

            return false;
        }
        public bool DoesGenreExist(Song song)
        {
            _logger.Info("Checking to see if Genre record exists");

            try
            {
                using (var conn = GetConnection())
                {
                    conn.Open();

                    var query = "SELECT gnr.*, 0 AS SongCount FROM Genre gnr WHERE " +
                        "gnr.GenreName=@GenreName";

                    using (var cmd = new MySqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@GenreName", song.Genre);

                        using (var reader = cmd.ExecuteReader())
                        {
                            var genre = ParseSingleData(reader);
                            var genreName = genre.GenreName;

                            if (!string.IsNullOrEmpty(genreName))
                            {
                                _logger.Info("Genre exists");

                                return true;
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
                _logger.Error(msg, "An error occurred");
            }

            _logger.Info("Genre does not exist");

            return false;
        }

        public void SaveGenre(Genre genre)
        {
            _logger.Info("Saving Genre record");

            try
            {
                using (var conn = GetConnection())
                {
                    conn.Open();

                    var query = "INSERT INTO Genre(GenreName) VALUES(@GenreName)";

                    using (var cmd = new MySqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@GenreName", genre.GenreName);

                        cmd.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
                _logger.Error(msg, "An error occurred");
            }
        }
        public void UpdateGenre(Genre genre)
        {
            _logger.Info("Updating Genre record");

            try
            {
                using (var conn = GetConnection())
                {
                    conn.Open();

                    var query = "UPDATE Genre SET GenreName=@GenreName " +
                        "WHERE GenreId=@GenreId";

                    using (var cmd = new MySqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@GenreName", genre.GenreName);
                        cmd.Parameters.AddWithValue("@GenreId", genre.GenreId);

                        cmd.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
                _logger.Error(msg, "An error occurred");
            }
        }
        public void DeleteGenre(Genre genre)
        {
            _logger.Info("Deleting Genre record");

            try
            {
                using (var conn = GetConnection())
                {
                    conn.Open();

                    var query = "DELETE FROM Genre WHERE GenreId=@GenreId";

                    using (var cmd = new MySqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@GenreId", genre.GenreId);

                        cmd.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
                _logger.Error(msg, "An error occurred");
            }
        }

        private List<Genre> ParseData(MySqlDataReader reader)
        {
            var genres = new List<Genre>();
            _logger.Info("Retrieving genre records");

            while (reader.Read())
            {
                var id = Convert.ToInt32(reader["GenreId"].ToString());
                var genreName = reader["GenreName"].ToString();
                var songCount = Convert.ToInt32(reader["SongCount"].ToString());

                genres.Add(new Genre
                {
                    GenreId = id,
                    GenreName = genreName,
                    SongCount = songCount
                });
            }

            _logger.Info("Genre records retrieved");

            return genres;
        }

        private Genre ParseSingleData(MySqlDataReader reader)
        {
            var genre = new Genre();
            _logger.Info("Retrieving single genre record");

            while (reader.Read())
            {
                var id = Convert.ToInt32(reader["GenreId"].ToString());
                var genreName = reader["GenreName"].ToString();
                var songCount = Convert.ToInt32(reader["SongCount"].ToString());
                genre.GenreId = id;
                genre.GenreName = genreName;
                genre.SongCount = songCount;
            }

            _logger.Info("Single genre record retrieved");

            return genre;
        }

        private bool AnyGenre()
        {
            try
            {
                using (var conn = GetConnection())
                {
                    conn.Open();

                    var query = "SELECT * FROM Genre";

                    using (var cmd = new MySqlCommand(query, conn))
                        using (var reader = cmd.ExecuteReader())
                            return reader.HasRows;
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
                _logger.Error(msg, "An error occurred");
            }

            _logger.Info("No genre records found");

            return false;
        }
        #endregion
    }
}