public void farm(Block block) {
    this.area++;
    this.lastFarm = System.currentTimeMillis();
    this.first = false;
    state.addBlockToRegen(block);
    getColor().getBlock().apply(block);
    List < LinkedList < Block >> tracks = new ArrayList < LinkedList < Block >> ();
    List < LinkedList < Block >> closedPolygons = new ArrayList < LinkedList < Block >> ();

    tracks.add(new LinkedList < Block > (Arrays.asList(block)));

    while (tracks.size() != 0) {
        LinkedList < Block > track = tracks.get(0);
        Block currentBlock = track.getLast();

        List < BlockFace > matchingFaces = new ArrayList < BlockFace > ();

        for (BlockFace face: Arrays.asList(new BlockFace[] {
            BlockFace.NORTH, BlockFace.SOUTH, BlockFace.EAST, BlockFace.WEST
        }))
        if (getColor().getBlock().match(currentBlock.getRelative(face))) matchingFaces.add(face);

        int index;
        if ((index = track.indexOf(currentBlock)) > 0) matchingFaces.remove(currentBlock.getFace(track.get(index - 1)));
        else if (matchingFaces.size() < 2) return;

        if (matchingFaces.size() == 0) {
            tracks.remove(track);
            continue;
        }

        for (index = 0; index < matchingFaces.size(); index++) {
            if (track.contains(currentBlock.getRelative(matchingFaces.get(index)))) {
                if (currentBlock.getRelative(matchingFaces.get(index)).equals(block)) closedPolygons.add(track);
                tracks.remove(track); //crash ici
                continue;
            }

            if (index == matchingFaces.size() - 1) {
                track.add(currentBlock.getRelative(matchingFaces.get(index)));
                break;
            }

            LinkedList < Block > newTrack = new LinkedList < Block > (track);
            newTrack.add(currentBlock.getRelative(matchingFaces.get(index)));
            tracks.add(newTrack);
        }
    }

    getPlayer().sendMessage("Polygons: " + closedPolygons.size());

    for (LinkedList < Block > polygon: closedPolygons) {
        int xPos[] = new int[polygon.size()], zPos[] = new int[polygon.size()];

        for (int i = 0; i < polygon.size(); i++) {
            xPos[i] = polygon.get(i).getX();
            zPos[i] = polygon.get(i).getZ();
        }

        Polygon poly = new Polygon(xPos, zPos, polygon.size());

        List < Block > contained = new ArrayList < Block > ();

        int minX = MathUtil.getMin(xPos), maxX = MathUtil.getMax(xPos) + 1;
        int minZ = MathUtil.getMin(zPos), maxZ = MathUtil.getMax(zPos) + 1;

        for (int x = minX; x < maxX; x++)
        for (int z = minZ; z < maxZ; z++)
        if (poly.contains(x, z)) contained.add(block.getWorld().getBlockAt(x, block.getY(), z));

        boolean doContinue = false;

        for (Block containedBlock: contained) {
            if (!((BlockFarmersConfig) state.getGame().getConfig()).canFarm(containedBlock)) {
                doContinue = true;
                break;
            }
        }

        getPlayer().sendMessage("  Blocks: " + contained.size());

        if (doContinue) continue;

        for (Block containedBlock: contained) {
            state.addBlockToRegen(containedBlock);
            getColor().getBlock().apply(containedBlock);
        }
    }

}