package funkin.play.song;

import funkin.play.song.SongData.SongChartData;
import funkin.play.song.SongData.SongMetadata;
import funkin.util.VersionUtil;

class SongMigrator
{
  /**
   * The current latest version string for the song data format.
   * Handle breaking changes by incrementing this value
   * and adding migration to the SongMigrator class.
   */
  public static final CHART_VERSION:String = "2.0.0";

  public static final CHART_VERSION_RULE:String = "2.0.x";

  public static function migrateSongMetadata(jsonData:Dynamic, songId:String):SongMetadata
  {
    if (jsonData.version)
    {
      if (VersionUtil.validateVersion(jsonData.version, CHART_VERSION_RULE))
      {
        trace('Song (${songId}) metadata version (${jsonData.version}) is valid and up-to-date.');

        var songMetadata:SongMetadata = cast jsonData;

        return songMetadata;
      }
      else
      {
        trace('Song (${songId}) metadata version (${jsonData.version}) is outdated.');
        switch (jsonData.version)
        {
          // TODO: Add migration functions as cases here.
          default:
            // Unknown version.
            trace('Song (${songId}) unknown metadata version: ${jsonData.version}');
        }
      }
    }
    else
    {
      trace('Song metadata version is missing.');
    }
    return null;
  }

  public static function migrateSongChartData(jsonData:Dynamic, songId:String):SongChartData
  {
    if (jsonData.version)
    {
      if (VersionUtil.validateVersion(jsonData.version, CHART_VERSION_RULE))
      {
        trace('Song (${songId}) chart version (${jsonData.version}) is valid and up-to-date.');

        var songChartData:SongChartData = cast jsonData;

        return songChartData;
      }
      else
      {
        trace('Song (${songId}) chart version (${jsonData.version}) is outdated.');
        switch (jsonData.version)
        {
          // TODO: Add migration functions as cases here.
          default:
            // Unknown version.
            trace('Song (${songId}) unknown chart version: ${jsonData.version}');
        }
      }
    }
    else
    {
      trace('Song chart version is missing.');
    }
    return null;
  }
}