Refactoring

Controllers/Managers/GenreManager.cs

@@ -1,6 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.Configuration;
+using System.Linq;
+
+using Microsoft.Extensions.Configuration;
 
 using Icarus.Controllers.Utilities;
 using Icarus.Models;
@@ -11,6 +14,7 @@ namespace Icarus.Controllers.Managers
     public class GenreManager : BaseManager
     {
     	#region Fields
+		private GenreContext _genreContext;
     	#endregion
 
 
@@ -19,10 +23,115 @@ namespace Icarus.Controllers.Managers
 
 
     	#region Constructors
+		public GenreManager(IConfiguration config)
+		{
+			_config = config;
+			_connectionString = _config.GetConnectionString("DefaultConnection");
+			_genreContext = new GenreContext(_connectionString);
+		}
     	#endregion
 
 
     	#region Methods
+        public void SaveGenreToDatabase(ref Song song)
+        {
+            _logger.Info("Starting process to save the genre record of the song to the database");
+
+            var genre = new Genre
+            {
+                GenreName = song.Genre,
+                SongCount = 1
+            };
+
+            var genreName = song.Genre;
+            var genreRetrieved = _genreContext.Genres.FirstOrDefault(gnr => gnr.GenreName.Equals(genreName));
+
+            if (genreRetrieved == null)
+            {
+                _genreContext.Add(genre);
+                _genreContext.SaveChanges();
+            }
+            else
+            {
+                genre.GenreID = genreRetrieved.GenreID;
+            }
+
+            song.GenreID = genre.GenreID;
+        }
+
+        public Genre UpdateGenreInDatabase(Song oldSongRecord, Song newSongRecord)
+        {
+            var oldGenreRecord = _genreContext.Genres.FirstOrDefault(gnr => gnr.GenreName.Equals(oldSongRecord.Genre));
+            var oldGenreName = oldGenreRecord.GenreName;
+            var newGenreName = newSongRecord.Genre;
+
+            if (string.IsNullOrEmpty(newGenreName) || oldGenreName.Equals(newGenreName))
+            {
+                _logger.Info("No change to the song's Genre");
+                return oldGenreRecord;
+            }
+
+            _logger.Info("Change to the song's genre found");
+
+            if (oldGenreRecord.SongCount <= 1)
+            {
+                _logger.Info("Deleting genre record");
+
+                _genreContext.Remove(oldGenreRecord);
+                _genreContext.SaveChanges();
+            }
+
+            if (!(_genreContext.Genres.FirstOrDefault(gnr => gnr.GenreName.Equals(oldSongRecord.Genre)) != null))
+            {
+                _logger.Info("Creating new genre record");
+
+                var newGenreRecord = new Genre
+                {
+                    GenreName = newGenreName
+                };
+
+                _genreContext.Add(newGenreRecord);
+                _genreContext.SaveChanges();
+
+                return newGenreRecord;
+            }
+            else
+            {
+                _logger.Info("Updating existing genre record");
+
+                var existingGenreRecord = _genreContext.Genres.FirstOrDefault(gnr => gnr.GenreName.Equals(oldGenreRecord.GenreName));
+
+                _genreContext.Update(existingGenreRecord);
+                _genreContext.SaveChanges();
+
+                return existingGenreRecord;
+            }
+        }
+
+        public void DeleteGenreFromDatabase(Song song)
+        {
+            if (!(_genreContext.Genres.FirstOrDefault(gnr => gnr.GenreName.Equals(song.Genre)) != null))
+            {
+                _logger.Info("Cannot delete the genre record because it does not exist");
+                return;
+            }
+
+            var genre = _genreContext.Genres.FirstOrDefault(gnr => gnr.GenreName.Equals(song.Genre));
+
+            if (SongsInGenre(genre) <= 1)
+            {
+                _genreContext.Remove(genre);
+                _genreContext.SaveChanges();
+            }
+        }
+
+		private int SongsInGenre(Genre genre)
+		{
+			var sngContext = new SongContext(_connectionString);
+			var songs = sngContext.Songs.Where(sng => sng.GenreID == genre.GenreID).ToList();
+
+			return songs.Count;
+		}
     	#endregion
     }
 }