import lombok.AllArgsConstructor;
import lombok.Data;

import java.util.*;

public class Debug{
	public static void main(String[] args) throws Exception {
		GameGroup skyWars = new GameGroup("skyWars");
		GameGroup bedWars = new GameGroup("bedWars");

		List<PlayGame> playGames = new ArrayList<>();

		playGames.add(new PlayGame(new Party(1), skyWars, Arrays.asList("karta1", "karta2")));
		playGames.add(new PlayGame(new Party(2), bedWars, null));
		playGames.add(new PlayGame(new Party(3), skyWars, null));
		playGames.add(new PlayGame(new Party(4), skyWars, Arrays.asList("karta1")));
		playGames.add(new PlayGame(new Party(5), bedWars, null));
		playGames.add(new PlayGame(new Party(6), bedWars, Arrays.asList("karta1")));
		playGames.add(new PlayGame(new Party(7), skyWars, null));

		List<Session> sessions = new ArrayList<>();

		// идем по очереди и создаем сессию на каждую GameGroup+карту, которые есть в очереди
		for(PlayGame playGame : playGames){
			List<String> maps = playGame.getMapNames();
			if(maps == null){
				Session session = sessions.stream()
						.filter(it -> it.getGameGroup().equals(playGame.getGameGroup()))
						.findFirst().orElse(null);
				if(session == null){
					sessions.add(new Session(playGame.getGameGroup(), null));
				}
			} else {
				for(String map : maps){
					Session session = sessions.stream()
							.filter(it -> it.getGameGroup().equals(playGame.getGameGroup()))
							.filter(it -> Objects.equals(it.getMapName(), map))
							.findFirst().orElse(null);
					if(session == null){
						sessions.add(new Session(playGame.getGameGroup(), map));
					}
				}
			}
		}

		for(PlayGame playGame : playGames){
			for(Session session : sessions){
				if(session.getGameGroup().equals(playGame.getGameGroup())){
					if(playGame.getMapNames() == null){
						// если искомая карта - любая, то добавляем во все сессии с таким же GameGroup
						session.getPlayGames().add(playGame);
					} else if (playGame.getMapNames().contains(session.getMapName())) {
						// в противном случае добавляем только в те сессии, где такая же карта
						session.getPlayGames().add(playGame);
					}
				}
			}
		}

		for(Session session : sessions){
			System.out.println("session: " + session.getGameGroup() + " with map " + session.getMapName() + ": ");
			for(PlayGame playGame : session.getPlayGames()){
				System.out.println("  playGame: " + playGame);
			}
		}
	}

	@Data
	@AllArgsConstructor
	public static class Party {
		private int id;

	}

	@Data
	@AllArgsConstructor
	public static class GameGroup {
		private String name;
	}

	@Data
	@AllArgsConstructor
	public static class PlayGame {
		private Party party;
		private GameGroup gameGroup;
		private List<String> mapNames;
	}

	@Data
	public static class Session {
		private GameGroup gameGroup;
		private String mapName;
		private Set<PlayGame> playGames = new HashSet<>();

		public Session(GameGroup gameGroup, String mapName){
			this.gameGroup = gameGroup;
			this.mapName = mapName;
		}
	}
}