efibs / mc-lasertag-mod

public class SpawnpointManager implements ISpawnpointManager {

    private final HashMap<TeamDto, ArrayList<BlockPos>> spawnpointCache = new HashMap<>();

    private final ITeamsConfigState teamsConfigState;

    public SpawnpointManager(ITeamsConfigState teamsConfigState) {

        this.teamsConfigState = teamsConfigState;

    }

    /**

     * Gets all spawnpoints for the given team from the cache

     *

     * @param team

     * @return

     */

    @Override

    public ArrayList<BlockPos> getSpawnpoints(TeamDto team) {

        return spawnpointCache.get(team);

    }

    /**

     * Gets all spawnpoints for all teams in a unified list

     *

     * @return

     */

    @Override

    public List<BlockPos> getAllSpawnpoints() {

        return spawnpointCache.entrySet().stream()

                .flatMap(entry -> entry.getValue().stream())

                .toList();

    }

    @Override

    public void initSpawnpointCacheIfNecessary(ServerWorld world, boolean scanSpawnpoints) {

        if (spawnpointCache.isEmpty() || scanSpawnpoints) {

            initSpawnpointCache(world);

        }

    }

    @Override

    public void clearSpawnpointCache() {

        this.spawnpointCache.clear();

    }

    /**

     * Initializes the spawnpoint cache. Searches a 31 x 31 chunk area for spawnpoint blocks specified by the team.

     * This method is computationally intensive, don't call too often or when responsiveness is important. The call of this method blocks the server from ticking!

     */

    private void initSpawnpointCache(ServerWorld world) {

        try {

            this.spawnpointCache.clear();

            // Initialize team lists

            for (var team : teamsConfigState.getTeams()) {

                // Skip spectators

                if (team.equals(TeamsConfigState.SPECTATORS)) {

                    continue;

                }

                spawnpointCache.put(team, new ArrayList<>());

            }

            // Start time measurement

            var startTime = System.nanoTime();

            // Iterate over blocks and find spawnpoints

            world.fastSearchBlock((block, pos) -> {

                for (var teamDto : teamsConfigState.getTeams()) {

                    // Skip spectators

                    if (teamDto.equals(TeamsConfigState.SPECTATORS)) {

                        continue;

                    }

                    if (teamDto.spawnpointBlock().equals(block)) {

                        var team = spawnpointCache.get(teamDto);

                        synchronized (this) {

                            team.add(pos);

                        }

                        break;

                    }

                }

            }, (currChunk, maxChunk) -> {

                // Only send a progress update every second chunk to not ddos our players

                if (currChunk % 2 == 0) {

                    return;

                }

                // Create packet buffer

                var buf = new PacketByteBuf(Unpooled.buffer());

                // Write progress to buffer

                buf.writeDouble((double) currChunk / (double) maxChunk);

                ServerEventSending.sendToEveryone(world.getServer(), NetworkingConstants.PROGRESS, buf);

            });

            // Stop time measurement

            var stopTime = System.nanoTime();

            var duration = (stopTime - startTime) / 1000000000.0;

            LasertagMod.LOGGER.info("Spawnpoint search took " + duration + "s.");

        } catch (Exception ex) {

            LasertagMod.LOGGER.error("Unexpected error while scanning for spawnpoints: ", ex);

        } finally {

            // Create packet buffer

            var buf = new PacketByteBuf(Unpooled.buffer());

            // Write progress to buffer

            buf.writeDouble(-1.0F);

            ServerEventSending.sendToEveryone(world.getServer(), NetworkingConstants.PROGRESS, buf);