public class BlockPattern
{
    public interface PatternElement
    {
        boolean match(World world, BlockPos position);
    }

    public static class Layer
    {
        public static class Row
        {
            private final List<PatternElement> elements;

            public Row(List<PatternElement> elements)
            {
                this.elements = elements;
            }

            public boolean match(World world, BlockPos position)
            {
                for (int z = 0; z < elements.size(); z++)
                    if (!elements.get(z).match(world, position.add(0, 0, z)))
                        return false;
                return true;
            }
        }

        private final List<Row> rows;
        private final int minOccurrence;
        private final int maxOccurrence;

        public Layer(List<Row> rows, int minOccurrence, int maxOccurrence)
        {
            this.rows = rows;
            this.minOccurrence = minOccurrence;
            this.maxOccurrence = maxOccurrence;
        }

        public int match(World world, BlockPos position)
        {
            int y = 0;
            occurrences:
            for (; y < maxOccurrence; y++)
            {
                for (int x = 0; x < rows.size(); x++)
                {
                    Row row = rows.get(x);
                    boolean rowMatch = row.match(world, position.add(x, y, 0));
                    if (!rowMatch)
                    {
                        y -= 1;
                        break occurrences;
                    }
                }
            }
            if (y < minOccurrence)
                return -1;
            return y + 1;
        }
    }

    private final List<Layer> layers;

    public BlockPattern(List<Layer> layers)
    {
        this.layers = layers;
    }

    public boolean match(World world, BlockPos position)
    {
        int y = 0;
        for (Layer layer : layers)
        {
            int match = layer.match(world, position.add(0, y, 0));
            if (match == -1)
                return false;
            else
                y += match;
        }
        return true;
    }
}