using UnityEngine;

public class CameraFollow : MonoBehaviour {

	public Vector3 MiddlePosition;

	[Header ("Player Targets")]
	public GameObject[] targets;

	[Header ("Follow Settings")]
	public float distanceToTarget = 10; // The distance to the target
	public float heightOffset = -2; // the height offset of the camera relative to it's target
	public float viewAngle = -6; //a downwards rotation
	public Vector3 AdditionalOffset; //any additional offset
	public bool FollowZAxis; //enable or disable the camera following the z axis

	[Header ("Damp Settings")]
	public float DampX = 3f;
	public float DampY = 2f;
	public float DampZ = 3f;

	[Header ("View Area")]
	public float MinLeft;
	public float MaxRight;

	[Header ("Wave Area collider")]
	public bool UseWaveAreaCollider;
	public BoxCollider CurrentAreaCollider;
	public float AreaColliderViewOffset;
	private bool firstFrameActive;

	void Start(){
		UpdatePlayerTargets();
		firstFrameActive = true;
	}

	void Update () {
		if (targets.Length > 0){
			MiddlePosition = Vector3.zero;

			if(targets.Length == 1){

				//follow a single target
				if(targets[0] != null) MiddlePosition = targets[0].transform.position;

			} else {

				//find center position between multiple targets
				int count = 0;
				for(int i=0; i<targets.Length; i++){
					if(targets[i]){
						MiddlePosition += targets[i].transform.position;
						count ++;
					}
				}
				MiddlePosition = MiddlePosition / count;
			}

			//initial values
			float currentX = transform.position.x;
			float currentY = transform.position.y;
			float currentZ = transform.position.z;

			//Damp X
			currentX = Mathf.Lerp(currentX, MiddlePosition.x, DampX * Time.deltaTime);

			//DampY
			currentY = Mathf.Lerp(currentY, 3.9f, DampY * Time.deltaTime);

			//DampZ
			if (FollowZAxis) { 
				currentZ = Mathf.Lerp (currentZ, MiddlePosition.z + distanceToTarget, DampZ * Time.deltaTime);
			} else {
				currentZ = distanceToTarget;
			}

			//set values for 1st frame (No damping)
			if(firstFrameActive){ 
				firstFrameActive = false;
				currentX = MiddlePosition.x;
				currentY = MiddlePosition.y - heightOffset;
				currentZ = FollowZAxis? (MiddlePosition.z + distanceToTarget) : distanceToTarget;
			}

			//Set cam position
			if(CurrentAreaCollider == null) UseWaveAreaCollider = false;
			if (!UseWaveAreaCollider) {
				transform.position = new Vector3 (Mathf.Clamp (currentX, MaxRight, MinLeft), currentY, currentZ) + AdditionalOffset;
			} else {
				transform.position = new Vector3 (Mathf.Clamp (currentX, CurrentAreaCollider.transform.position.x + AreaColliderViewOffset, MinLeft), currentY, currentZ) + AdditionalOffset;
			}

			//Set cam rotation
			transform.rotation = new Quaternion(0,180f,viewAngle,0);
		}
	}

	//updates the targets to follow
	public void UpdatePlayerTargets(){
		targets = GameObject.FindGameObjectsWithTag ("Player");
	}
}