using UnityEngine;
using System.Collections;

public class VoxelRender : MonoBehaviour {
	//Expects a cubic number of elements
	private string world = "11111111";

	struct Voxel {
		public readonly int x;
		public readonly int y;
		public readonly int z;

		public Voxel (int x, int y, int z)
		{
			this.x = x;
			this.y = y;
			this.z = z;
		}

		public Voxel add(int x, int y, int z) {
			return new Voxel (this.x + x, this.y + y, this.z + z);
		}
	}

	void Start() {
		DrawWorld (world);
	}

	private void DrawWorld(string world) {
		var voxel = new Voxel (0, 0, 0);
		var worldDataLength = world.Length;
		Debug.Log ("WORLD DATA LENGTH " + worldDataLength);
		var worldSize = Mathf.RoundToInt(Mathf.Pow (worldDataLength, (1.0f / 3.0f)));
		Debug.Log ("WORLD SIZE " + worldSize);
		DrawBoxRecursively (world, worldSize, voxel, worldSize);
	}

	private void DrawBoxRecursively(string world, int worldSize, Voxel lowestXYZ, int size) {
		if (IsBoxFilled (world, worldSize, lowestXYZ, size)) {
			DrawBox(lowestXYZ, size);
		}
		else if(size > 1) {
			size = size / 2;
			var v = lowestXYZ;
			var voxels = new Voxel[] {
				v.add(0,0,0),
				v.add(size, 0, 0),
				v.add(0, size, 0),
				v.add(0, 0, size),
				v.add(size, 0, size),
				v.add(size, size, 0),
				v.add(0, size, size),
				v.add(size, size, size)
			};
			foreach(var voxel in voxels) {
				DrawBoxRecursively(world, worldSize, voxel, size);
			}
		}
	}

	private void DrawBox(Voxel lowestXYZ, int size) {
		var center = new Vector3 ((float)lowestXYZ.x + size * 0.5f, (float)lowestXYZ.y + size * 0.5f, (float)lowestXYZ.z + size * 0.5f);
		var transform = GameObject.CreatePrimitive (PrimitiveType.Cube).transform;
		transform.position = center;
		transform.localScale = new Vector3 (size - 0.1f, size - 0.1f, size - 0.1f);
	}

	private bool IsBoxFilled(string world, int worldSize, Voxel lowestXYZ, int size) {
		for(var x = lowestXYZ.x; x < lowestXYZ.x + size; x++) {
			for(var y = lowestXYZ.y; y < lowestXYZ.y + size; y++) {
				for(var z = lowestXYZ.z; z < lowestXYZ.z + size; z++) {
					if(!IsVoxelFilled(world, worldSize, new Voxel(x, y, z))) {
						return false;
					}
				}
			}
		}
		return true;
	}

	private bool IsVoxelFilled(string world, int worldSize, Voxel v) {
		var index = worldSize * worldSize * v.x + worldSize * v.y + v.z;
		return world[index] == '1';
	}
}