/************************************************************************************

See SampleFramework license.txt for license terms.  Unless required by applicable law 
or agreed to in writing, the sample code is provided “AS IS” WITHOUT WARRANTIES OR 
CONDITIONS OF ANY KIND, either express or implied.  See the license for specific 
language governing permissions and limitations under the license.

************************************************************************************/

using UnityEngine;

/// <summary>
/// This target handler will only return locations that the aim system detects that contain a TeleportPoint component.
/// </summary>
public class TeleportTargetHandlerNode : TeleportTargetHandler
{
	/// <summary>
	/// When checking line of sight to the destination, add this value to the vertical offset for targeting collision checks.
	/// </summary>
	[Tooltip("When checking line of sight to the destination, add this value to the vertical offset for targeting collision checks.")]
	public float LOSOffset = 1.0f;

	/// <summary>
	/// Teleport logic will only work with TeleportPoint components that exist in the layers specified by this mask.
	/// </summary>
	[Tooltip("Teleport logic will only work with TeleportPoint components that exist in the layers specified by this mask.")]
	public LayerMask TeleportLayerMask;

	/// <summary>
	/// This method will be called while the LocmotionTeleport component is in the aiming state, once for each
	/// line segment that the targeting beam requires. 
	/// The function should return true whenever an actual target location has been selected.
	/// </summary>
	protected override bool ConsiderTeleport(Vector3 start, ref Vector3 end)
	{
		// If the ray hits the world, consider it valid and update the aimRay to the end point.
		if (!LocomotionTeleport.AimCollisionTest(start, end, AimCollisionLayerMask | TeleportLayerMask, out AimData.TargetHitInfo))
		{
			return false;
		}
		TeleportPoint tp = AimData.TargetHitInfo.collider.gameObject.GetComponent<TeleportPoint>();
		if (tp == null)
		{
			return false;
		}

		// The targeting test discovered a valid teleport node. Now test to make sure there is line of sight to the 
		// actual destination. Since the teleport destination is expected to be right on the ground, use the LOSOffset 
		// to bump the collision check up off the ground a bit.
		var dest = tp.destTransform.position;
		var offsetEnd = new Vector3(dest.x, dest.y + LOSOffset, dest.z);
		if (LocomotionTeleport.AimCollisionTest(start, offsetEnd, AimCollisionLayerMask & ~TeleportLayerMask, out AimData.TargetHitInfo))
		{
			return false;
		}

		end = dest;
		return true;
	}
}