using FluentMigrator;
using NzbDrone.Core.Datastore.Migration.Framework;

namespace NzbDrone.Core.Datastore.Migration
{
    [Migration(31)]
    public class add_artistmetadataid_constraint : NzbDroneMigrationBase
    {
        protected override void MainDbUpgrade()
        {
            // Remove any duplicate artists
            Execute.Sql(@"DELETE FROM ""Artists""
                          WHERE ""Id"" NOT IN (
                            SELECT MIN(""Artists"".""Id"") from ""Artists""
                            JOIN ""ArtistMetadata"" ON ""Artists"".""ArtistMetadataId"" = ""ArtistMetadata"".""Id""
                            GROUP BY ""ArtistMetadata"".""Id"")");

            // The index exists but will be recreated as part of unique constraint
            Delete.Index().OnTable("Artists").OnColumn("ArtistMetadataId");

            // Add a constraint to prevent any more duplicates
            Alter.Column("ArtistMetadataId").OnTable("Artists").AsInt32().Unique();
        }
    }
}