using UnityEngine;
using System.Collections;

using Cubiquity;

public class ClickToCarveTerrainVolume : MonoBehaviour
{
    private TerrainVolume terrainVolume;

    // Bit of a hack - we want to detect mouse clicks rather than the mouse simply being down,
    // but we can't use OnMouseDown because the voxel terrain doesn't have a collider (the
    // individual pieces do, but not the parent). So we define a click as the mouse being down
    // but not being down on the previous frame. We'll fix this better in the future...
    private bool isMouseAlreadyDown = false;

    // Use this for initialization
    void Start ()
    {
        // We'll store a reference to the colored cubes volume so we can interact with it later.
        terrainVolume = gameObject.GetComponent<TerrainVolume>();
        if(terrainVolume == null)
        {
            Debug.LogError("This 'ClickToCarveTerrainVolume' script should be attached to a game object with a TerrainVolume component");
        }
    }

    // Update is called once per frame
    void Update ()
    {
        // Bail out if we're not attached to a terrain.
        if(terrainVolume == null)
        {
            return;
        }

        // If the mouse btton is down and it was not down last frame
        // then we consider this a click, and do our destruction.
        if(Input.GetMouseButton(0))
        {
            if(!isMouseAlreadyDown)
            {
                // Build a ray based on the current mouse position
                Vector2 mousePos = Input.mousePosition;
                Ray ray = Camera.main.ScreenPointToRay(new Vector3(mousePos.x, mousePos.y, 0));

                // Perform the raycasting.
                PickSurfaceResult pickResult;
                bool hit = Picking.PickSurface(terrainVolume, ray, 1000.0f, out pickResult);

                // If we hit a solid voxel then create an explosion at this point.
                if(hit)
                {
                    int range = 10;
                    CountVoxels((int)pickResult.volumeSpacePos.x, (int)pickResult.volumeSpacePos.y, (int)pickResult.volumeSpacePos.z, range);
                    DestroyVoxels((int)pickResult.volumeSpacePos.x, (int)pickResult.volumeSpacePos.y, (int)pickResult.volumeSpacePos.z, range);
                    CountVoxels((int)pickResult.volumeSpacePos.x, (int)pickResult.volumeSpacePos.y, (int)pickResult.volumeSpacePos.z, range);
                }

                // Set this flag so the click won't be processed again next frame.
                isMouseAlreadyDown = true;
            }
        }
        else
        {
            // Clear the flag while we wait for a click.
            isMouseAlreadyDown = false;
        }
    }

    void DestroyVoxels(int xPos, int yPos, int zPos, int range)
    {
        // Initialise outside the loop, but we'll use it later.
        int rangeSquared = range * range;
        MaterialSet emptyMaterialSet = new MaterialSet();

        // Iterage over every voxel in a cubic region defined by the received position (the center) and
        // the range. It is quite possible that this will be hundreds or even thousands of voxels.
        for(int z = zPos - range; z < zPos + range; z++)
        {
            for(int y = yPos - range; y < yPos + range; y++)
            {
                for(int x = xPos - range; x < xPos + range; x++)
                {
                    // Compute the distance from the current voxel to the center of our explosion.
                    int xDistance = x - xPos;
                    int yDistance = y - yPos;
                    int zDistance = z - zPos;

                    // Working with squared distances avoids costly square root operations.
                    int distSquared = xDistance * xDistance + yDistance * yDistance + zDistance * zDistance;

                    // We're iterating over a cubic region, but we want our explosion to be spherical. Therefore
                    // we only further consider voxels which are within the required range of our explosion center.
                    // The corners of the cubic region we are iterating over will fail the following test.
                    if(distSquared < rangeSquared)
                    {
                        terrainVolume.data.SetVoxel(x, y, z, emptyMaterialSet);
                    }
                }
            }
        }

        range += 2;

        TerrainVolumeEditor.BlurTerrainVolume(terrainVolume, new Region(xPos - range, yPos - range, zPos - range, xPos + range, yPos + range, zPos + range));
        //TerrainVolumeEditor.BlurTerrainVolume(terrainVolume, new Region(xPos - range, yPos - range, zPos - range, xPos + range, yPos + range, zPos + range));
        //TerrainVolumeEditor.BlurTerrainVolume(terrainVolume, new Region(xPos - range, yPos - range, zPos - range, xPos + range, yPos + range, zPos + range));
    }

    void CountVoxels(int xPos, int yPos, int zPos, int range)
    {
        // Initialise outside the loop, but we'll use it later.
        int rangeSquared = range * range;

        int totalMaterialWeight = 0;
        int noOfSolidVoxels = 0;
        int noOfEmptyVoxels = 0;

        // Iterage over every voxel in a cubic region defined by the received position (the center) and
        // the range. It is quite possible that this will be hundreds or even thousands of voxels.
        for(int z = zPos - range; z < zPos + range; z++)
        {
            for(int y = yPos - range; y < yPos + range; y++)
            {
                for(int x = xPos - range; x < xPos + range; x++)
                {
                    // Compute the distance from the current voxel to the center of our explosion.
                    int xDistance = x - xPos;
                    int yDistance = y - yPos;
                    int zDistance = z - zPos;

                    // Working with squared distances avoids costly square root operations.
                    int distSquared = xDistance * xDistance + yDistance * yDistance + zDistance * zDistance;

                    // We're iterating over a cubic region, but we want our explosion to be spherical. Therefore
                    // we only further consider voxels which are within the required range of our explosion center.
                    // The corners of the cubic region we are iterating over will fail the following test.
                    if(distSquared < rangeSquared)
                    {
                        int sumOfWeightsForThisVoxel = 0;
                        MaterialSet material = terrainVolume.data.GetVoxel(x, y, z);
                        for (uint i = 0; i < 8; i++)
                        {
                            sumOfWeightsForThisVoxel += material.weights[i];
                        }

                        totalMaterialWeight += sumOfWeightsForThisVoxel;

                        if(sumOfWeightsForThisVoxel > 127)
                        {
                            noOfSolidVoxels ++;
                        }
                        else
                        {
                            noOfEmptyVoxels++;
                        }
                    }
                }
            }
        }

        Debug.Log ("Found " + noOfSolidVoxels + " solid voxels and " + noOfEmptyVoxels + " empty voxels. Total amount of material was " + totalMaterialWeight + ".");
    }
}