using UnityEngine;
using System.Collections;

namespace EzySlice
{
	/**
     * Define Extension methods for easy access to slicer functionality
     */
	public static class SlicerExtensions
	{
        
		/**
         * SlicedHull Return functions and appropriate overrides!
         */
		public static SlicedHull Slice (this GameObject obj, Plane pl, Material crossSectionMaterial = null)
		{
			return Slice (obj, pl, new TextureRegion (0.0f, 0.0f, 1.0f, 1.0f), crossSectionMaterial);
		}

		public static SlicedHull SliceObject (this GameObject obj, Vector3 position, Vector3 direction, Material crossSectionMaterial = null)
		{
			return Slice (obj, position, direction, new TextureRegion (0.0f, 0.0f, 1.0f, 1.0f), crossSectionMaterial);
		}

		public static SlicedHull Slice (this GameObject obj, Vector3 position, Vector3 direction, TextureRegion textureRegion, Material crossSectionMaterial = null)
		{
			Plane cuttingPlane = new Plane ();

			Vector3 refUp = obj.transform.InverseTransformDirection (direction);
			Vector3 refPt = obj.transform.InverseTransformPoint (position);

			cuttingPlane.Compute (refPt, refUp);

			return Slice (obj, cuttingPlane, textureRegion, crossSectionMaterial);
		}

		public static SlicedHull Slice (this GameObject obj, Plane pl, TextureRegion textureRegion, Material crossSectionMaterial = null)
		{
			return Slicer.Slice (obj, pl, textureRegion, crossSectionMaterial);
		}

		/**
         * These functions (and overrides) will return the final indtaniated GameObjects types
         */
		public static GameObject[] SliceInstantiate (this GameObject obj, Plane pl)
		{
			return SliceInstantiate (obj, pl, new TextureRegion (0.0f, 0.0f, 1.0f, 1.0f));
		}

		public static GameObject[] SliceInstantiate (this GameObject obj, Vector3 position, Vector3 direction)
		{
			return SliceInstantiate (obj, position, direction, null);
		}

		public static GameObject[] SliceInstantiate (this GameObject obj, Vector3 position, Vector3 direction, Material crossSectionMat)
		{
			return SliceInstantiate (obj, position, direction, new TextureRegion (0.0f, 0.0f, 1.0f, 1.0f), crossSectionMat);
		}

		public static GameObject[] SliceInstantiate (this GameObject obj, Vector3 position, Vector3 direction, TextureRegion cuttingRegion, Material crossSectionMaterial = null)
		{
			EzySlice.Plane cuttingPlane = new EzySlice.Plane ();

			Vector3 refUp = obj.transform.InverseTransformDirection (direction);
			Vector3 refPt = obj.transform.InverseTransformPoint (position);

			cuttingPlane.Compute (refPt, refUp);

			return SliceInstantiate (obj, cuttingPlane, cuttingRegion, crossSectionMaterial);
		}

		public static GameObject[] SliceInstantiate (this GameObject obj, Plane pl, TextureRegion cuttingRegion, Material crossSectionMaterial = null)
		{
			SlicedHull slice = Slicer.Slice (obj, pl, cuttingRegion, crossSectionMaterial);

			if (slice == null) {
				return null;
			}

			GameObject upperHull = slice.CreateUpperHull (obj, crossSectionMaterial);
			GameObject lowerHull = slice.CreateLowerHull (obj, crossSectionMaterial);

			if (upperHull != null && lowerHull != null) {
				return new GameObject[] { upperHull, lowerHull };
			}

			// otherwise return only the upper hull
			if (upperHull != null) {
				return new GameObject[] { upperHull };
			}

			// otherwise return only the lower hull
			if (lowerHull != null) {
				return new GameObject[] { lowerHull };
			}

			// nothing to return, so return nothing!
			return null;
		}
	}
}