Allow rejoining River Race late

Author: Gegy

src/main/java/com/lovetropics/minigames/common/core/game/behavior/instances/JoinLateWithRoleBehavior.java

@@ -6,23 +6,63 @@
 import com.lovetropics.minigames.common.core.game.behavior.event.GamePlayerEvents;
 import com.lovetropics.minigames.common.core.game.player.PlayerRole;
 import com.lovetropics.minigames.common.core.game.player.PlayerRoleSelections;
+import com.lovetropics.minigames.common.core.game.state.statistics.PlayerKey;
+import com.lovetropics.minigames.common.core.game.state.team.GameTeamKey;
+import com.lovetropics.minigames.common.core.game.state.team.TeamState;
+import com.mojang.serialization.Codec;
 import com.mojang.serialization.MapCodec;
 import com.mojang.serialization.codecs.RecordCodecBuilder;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import net.minecraft.server.level.ServerPlayer;
 
-public record JoinLateWithRoleBehavior(PlayerRole role) implements IGameBehavior {
+import javax.annotation.Nullable;
+import java.util.Map;
+
+public record JoinLateWithRoleBehavior(PlayerRole role, boolean allowRejoin) implements IGameBehavior {
 	public static final MapCodec<JoinLateWithRoleBehavior> CODEC = RecordCodecBuilder.mapCodec(i -> i.group(
-			PlayerRole.CODEC.fieldOf("role").forGetter(c -> c.role)
+			PlayerRole.CODEC.fieldOf("role").forGetter(c -> c.role),
+			Codec.BOOL.optionalFieldOf("allow_rejoin", false).forGetter(c -> c.allowRejoin)
 	).apply(i, JoinLateWithRoleBehavior::new));
 
 	@Override
 	public void register(final IGamePhase game, final EventRegistrar events) {
+		final TeamState teams = game.instanceState().getOrNull(TeamState.KEY);
+		final Map<PlayerKey, OldParticipant> oldParticipants = new Object2ObjectOpenHashMap<>();
+
 		events.listen(GamePlayerEvents.SELECT_ROLE_ON_JOIN, player -> {
+			// Let the player be a spectator if they really want to
 			final PlayerRoleSelections roleSelections = game.lobby().getPlayers().getRoleSelections();
 			if (roleSelections.getSelectedRoleFor(player.id()) == PlayerRole.SPECTATOR) {
 				return PlayerRole.SPECTATOR;
-			} else {
-				return role;
 			}
+
+			OldParticipant oldParticipant = oldParticipants.remove(player);
+			if (allowRejoin && oldParticipant != null) {
+				// Yes, ok - we're not supposed to fetch the player before they join.
+				// But this whole player setup process is jank, and it's 5 days to the event. I made this mess, I can make it worse!
+				final ServerPlayer playerEntity = game.lobby().getPlayers().getPlayerBy(player.id());
+				if (playerEntity != null && teams != null && oldParticipant.team != null) {
+					teams.addPlayerTo(playerEntity, oldParticipant.team);
+				}
+				return PlayerRole.PARTICIPANT;
+			}
+
+			return role;
 		});
+
+		if (allowRejoin) {
+			events.listen(GamePlayerEvents.SET_ROLE, (player, role, lastRole) -> {
+				final PlayerKey playerKey = PlayerKey.from(player);
+				if (role == PlayerRole.PARTICIPANT) {
+					final GameTeamKey team = teams != null ? teams.getTeamForPlayer(player) : null;
+					oldParticipants.put(playerKey, new OldParticipant(team));
+				} else if (lastRole == PlayerRole.PARTICIPANT) {
+					oldParticipants.remove(playerKey);
+				}
+			});
+		}
+	}
+
+	private record OldParticipant(@Nullable GameTeamKey team) {
 	}
 }