public class WallBorderListener implements Listener {

    private static final int WALL_HEIGHT_DOWN_DIST = 3;
    private static final int WALL_HEIGHT_UP_DIST = 4;
    private static final int WALL_HORIZONTAL_DIST = 7;

    private final HCF plugin;

    public WallBorderListener(final HCF plugin) {
        this.plugin = plugin;
    }

    @EventHandler(ignoreCancelled = true, priority = EventPriority.MONITOR)
    public void onPlayerJoin(final PlayerSpawnLocationEvent event) {
        final Player player = event.getPlayer();
        Location location = event.getSpawnLocation();
        updateVisualWalls(player, location.getWorld(), location.getBlockX(), location.getBlockY(), location.getBlockZ());
    }

    @EventHandler(ignoreCancelled = true, priority = EventPriority.MONITOR)
    public void onPlayerMove(final PlayerMoveEvent event) {
        final Location to = event.getTo();
        final int toX = to.getBlockX();
        final int toY = to.getBlockY();
        final int toZ = to.getBlockZ();
        final Location from = event.getFrom();
        if (from.getBlockX() != toX || from.getBlockY() != toY || from.getBlockZ() != toZ) {
            this.updateVisualWalls(event.getPlayer(), to.getWorld(), toX, toY, toZ);
        }
    }

    @EventHandler(ignoreCancelled = true, priority = EventPriority.MONITOR)
    public void onPlayerTeleport(final PlayerTeleportEvent event) {
        this.onPlayerMove(event);
    }

    private void updateVisualWalls(Player player, final World toWorld, final int toX, final int toY, final int toZ) {
        BlockGenerator blockGenerator;
        if (plugin.getTimerManager().getCombatTimer().getRemaining(player) > 0L) {
            blockGenerator = Constants.SPAWN_TAG_WALL;
        } else {
            if (this.plugin.getTimerManager().getPvPProtectionTimer().getRemaining(player) > 0L) {
                blockGenerator = Constants.CLAIM_BORDER_WALL;
            } else {
                return;
            }
        }

        this.plugin.getBlockSender().clearBlocks(player, fakeBlock -> {
            Location location = fakeBlock.getLocation();
            return location.getWorld().equals(toWorld) && fakeBlock.getGenerator().equals(blockGenerator)
                    && (Math.abs(toX - location.getBlockX()) > WALL_HORIZONTAL_DIST
                    || Math.abs(toZ - location.getBlockZ()) > WALL_HORIZONTAL_DIST
                    || Math.abs(toY - location.getBlockY()) > WALL_HEIGHT_UP_DIST); //TODO WALL_HEIGHT_DOWN_DIST
        });

        final int minX = toX - WALL_HORIZONTAL_DIST;
        final int maxX = toX + WALL_HORIZONTAL_DIST;

        final int minY = toY - WALL_HEIGHT_UP_DIST; //TODO WALL_HEIGHT_DOWN_DIST
        final int maxY = toY + WALL_HEIGHT_UP_DIST;

        final int minZ = toZ - WALL_HORIZONTAL_DIST;
        final int maxZ = toZ + WALL_HORIZONTAL_DIST;

        Collection<Location> locations = null;
        for (int x = minX; x <= maxX; ++x) {
            for (int z = minZ; z <= maxZ; ++z) {
                final Faction faction = this.plugin.getFactionsManager().getFactionAt(toWorld, x, z);
                if (blockGenerator == Constants.SPAWN_TAG_WALL) {
                    if (!(faction instanceof SpawnFaction)) {
                        continue;
                    }
                } else if (blockGenerator == Constants.CLAIM_BORDER_WALL) {
                    if (faction instanceof RoadFaction) {
                        continue;
                    }
                    if (faction instanceof SpawnFaction) {
                        continue;
                    }
                    //TODO ignore for own faction.
                }
                final Collection<Claim> claims = faction.getClaim();
                for (Claim claim : claims) {
                    if (toWorld.equals(claim.getWorld())) {
                        final Location[] edges = claim.edges(minY, maxY);
                        for (final Location edge : edges) {
                            if (Math.abs(edge.getBlockX() - toX) > WALL_HORIZONTAL_DIST || Math.abs(edge.getBlockZ() - toZ) > WALL_HORIZONTAL_DIST) {
                                continue;
                            }

                            if (locations == null) locations = new ArrayList<>();
                            locations.add(edge);
                        }
                    }
                }
            }
        }

        if (locations != null) {
            plugin.getBlockSender().sendBlocks(player, blockGenerator, locations);
            locations.clear();
        }
    }
}