/******************************************************************************
 * Spine Runtimes Software License
 * Version 2.3
 * 
 * Copyright (c) 2013-2015, Esoteric Software
 * All rights reserved.
 * 
 * You are granted a perpetual, non-exclusive, non-sublicensable and
 * non-transferable license to use, install, execute and perform the Spine
 * Runtimes Software (the "Software") and derivative works solely for personal
 * or internal use. Without the written permission of Esoteric Software (see
 * Section 2 of the Spine Software License Agreement), you may not (a) modify,
 * translate, adapt or otherwise create derivative works, improvements of the
 * Software or develop new applications using the Software or (b) remove,
 * delete, alter or obscure any trademarks or any copyright, trademark, patent
 * or other intellectual property or proprietary rights notices on or in the
 * Software, including any copy thereof. Redistributions in binary or source
 * form must include this license and terms.
 * 
 * THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL ESOTERIC SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

using UnityEngine;
using System.Collections;

[RequireComponent(typeof(SkeletonUtilityBone)), ExecuteInEditMode]
public class SkeletonUtilityGroundConstraint : SkeletonUtilityConstraint {

#if UNITY_4_3
	public LayerMask groundMask;
	public bool use2D = false;
	public bool useRadius = false;
	public float castRadius = 0.1f;
	public float castDistance = 5f;
	public float castOffset = 0;
	public float groundOffset = 0;
	public float adjustSpeed = 5;
#else
	[Tooltip("LayerMask for what objects to raycast against")]
	public LayerMask groundMask;
	[Tooltip("The 2D")]
	public bool use2D = false;
	[Tooltip("Uses SphereCast for 3D mode and CircleCast for 2D mode")]
	public bool useRadius = false;
	[Tooltip("The Radius")]
	public float castRadius = 0.1f;
	[Tooltip("How high above the target bone to begin casting from")]
	public float castDistance = 5f;
	[Tooltip("X-Axis adjustment")]
	public float castOffset = 0;
	[Tooltip("Y-Axis adjustment")]
	public float groundOffset = 0;
	[Tooltip("How fast the target IK position adjusts to the ground.  Use smaller values to prevent snapping")]
	public float adjustSpeed = 5;
#endif


	Vector3 rayOrigin;
	Vector3 rayDir = new Vector3(0, -1, 0);
	float hitY;
	float lastHitY;

	protected override void OnEnable () {
		base.OnEnable();
		lastHitY = transform.position.y;
	}

	protected override void OnDisable () {
		base.OnDisable();
	}

	public override void DoUpdate () {
		rayOrigin = transform.position + new Vector3(castOffset, castDistance, 0);

		hitY = float.MinValue;
		if (use2D) {
			RaycastHit2D hit;

			if (useRadius) {
#if UNITY_4_3
				//NOTE:  Unity 4.3.x does not have CircleCast
				hit = Physics2D.Raycast(rayOrigin , rayDir, castDistance + groundOffset, groundMask);
#else
				hit = Physics2D.CircleCast(rayOrigin, castRadius, rayDir, castDistance + groundOffset, groundMask);
#endif
			} else {
				hit = Physics2D.Raycast(rayOrigin, rayDir, castDistance + groundOffset, groundMask);
			}

			if (hit.collider != null) {
				hitY = hit.point.y + groundOffset;
				if (Application.isPlaying) {
					hitY = Mathf.MoveTowards(lastHitY, hitY, adjustSpeed * Time.deltaTime);
				}
			} else {
				if (Application.isPlaying)
					hitY = Mathf.MoveTowards(lastHitY, transform.position.y, adjustSpeed * Time.deltaTime);
			}
		} else {
			RaycastHit hit;
			bool validHit = false;

			if (useRadius) {
				validHit = Physics.SphereCast(rayOrigin, castRadius, rayDir, out hit, castDistance + groundOffset, groundMask);
			} else {
				validHit = Physics.Raycast(rayOrigin, rayDir, out hit, castDistance + groundOffset, groundMask);
			}

			if (validHit) {
				hitY = hit.point.y + groundOffset;
				if (Application.isPlaying) {
					hitY = Mathf.MoveTowards(lastHitY, hitY, adjustSpeed * Time.deltaTime);
				}
			} else {
				if (Application.isPlaying)
					hitY = Mathf.MoveTowards(lastHitY, transform.position.y, adjustSpeed * Time.deltaTime);
			}
		}

		Vector3 v = transform.position;
		v.y = Mathf.Clamp(v.y, Mathf.Min(lastHitY, hitY), float.MaxValue);
		transform.position = v;

		utilBone.bone.X = transform.localPosition.x;
		utilBone.bone.Y = transform.localPosition.y;

		lastHitY = hitY;
	}

	void OnDrawGizmos () {
		Vector3 hitEnd = rayOrigin + (rayDir * Mathf.Min(castDistance, rayOrigin.y - hitY));
		Vector3 clearEnd = rayOrigin + (rayDir * castDistance);
		Gizmos.DrawLine(rayOrigin, hitEnd);

		if (useRadius) {
			Gizmos.DrawLine(new Vector3(hitEnd.x - castRadius, hitEnd.y - groundOffset, hitEnd.z), new Vector3(hitEnd.x + castRadius, hitEnd.y - groundOffset, hitEnd.z));
			Gizmos.DrawLine(new Vector3(clearEnd.x - castRadius, clearEnd.y, clearEnd.z), new Vector3(clearEnd.x + castRadius, clearEnd.y, clearEnd.z));
		}

		Gizmos.color = Color.red;
		Gizmos.DrawLine(hitEnd, clearEnd);
	}
}
