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

namespace NzbDrone.Core.Datastore.Migration
{
    [Migration(30)]
    public class add_mediafilerepository_mtime : NzbDroneMigrationBase
    {
        protected override void MainDbUpgrade()
        {
            Alter.Table("TrackFiles").AddColumn("Modified").AsDateTime().WithDefaultValue(new DateTime(2000, 1, 1));
            Alter.Table("TrackFiles").AddColumn("Path").AsString().Nullable();

            // Remove anything where RelativePath is null
            Execute.Sql(@"DELETE FROM ""TrackFiles"" WHERE ""RelativePath"" IS NULL");

            // Remove anything not linked to a track (these shouldn't be present in version < 30)
            Execute.Sql(@"DELETE FROM ""TrackFiles""
                          WHERE ""Id"" IN (
                            SELECT ""TrackFiles"".""Id"" FROM ""TrackFiles""
                            LEFT JOIN ""Tracks"" ON ""TrackFiles"".""Id"" = ""Tracks"".""TrackFileId""
                            WHERE ""Tracks"".""Id"" IS NULL)");

            // Remove anything where we can't get an artist path (i.e. we don't know where it is)
            Execute.Sql(@"DELETE FROM ""TrackFiles""
                          WHERE ""Id"" IN (
                            SELECT ""TrackFiles"".""Id"" FROM ""TrackFiles""
                            LEFT JOIN ""Albums"" ON ""TrackFiles"".""AlbumId"" = ""Albums"".""Id""
                            LEFT JOIN ""Artists"" ON ""Artists"".""ArtistMetadataId"" = ""Albums"".""ArtistMetadataId""
                            WHERE ""Artists"".""Path"" IS NULL)");

            // Remove anything linked to unmonitored or unidentified releases.  This should ensure uniqueness of track files.
            Execute.Sql(@"DELETE FROM ""TrackFiles""
                          WHERE ""Id"" IN (
                            SELECT ""TrackFiles"".""Id"" FROM ""TrackFiles""
                            LEFT JOIN ""Tracks"" ON ""TrackFiles"".""Id"" = ""Tracks"".""TrackFileId""
                            LEFT JOIN ""AlbumReleases"" ON ""Tracks"".""AlbumReleaseId"" = ""AlbumReleases"".""Id""
                            WHERE ""AlbumReleases"".""Monitored"" = false
                            OR ""AlbumReleases"".""Monitored"" IS NULL)");

            // Populate the full paths
            Execute.Sql(@"UPDATE ""TrackFiles""
                          SET ""Path"" = (SELECT ""Artists"".""Path"" || '" + System.IO.Path.DirectorySeparatorChar + @"' || ""TrackFiles"".""RelativePath""
                                      FROM ""Artists""
                                      JOIN ""Albums"" ON ""Albums"".""ArtistMetadataId"" = ""Artists"".""ArtistMetadataId""
                                      WHERE ""TrackFiles"".""AlbumId"" = ""Albums"".""Id"")");

            // Belt and braces to ensure uniqueness
            Execute.Sql(@"DELETE FROM ""TrackFiles""
                          WHERE ""Id"" NOT IN (
                            SELECT MIN(""Id"")
                            FROM ""TrackFiles""
                            GROUP BY ""Path""
                          )");

            // Now enforce the uniqueness constraint
            Alter.Table("TrackFiles").AlterColumn("Path").AsString().NotNullable().Unique();

            // Finally delete the relative path column
            Delete.Column("RelativePath").FromTable("TrackFiles");
        }
    }
}