using UnityEngine;
using System.Collections;

public class CameraClass : MonoBehaviour
{
	public PlayerControl target;

	private const float deg = Mathf.Deg2Rad;
	
	private float distance = 5.0f,
	angle = deg * 135.0f,
	targetangle = 0.0f, 
	yoffset = 4.8f,
	temp = 0.0f;
	
	private const float twoPi = Mathf.PI * 2;
	private const float deg45 = Mathf.PI / 4;
	
	private Vector3 point;
	
	void Start () 
	{
		targetangle = angle;
	}
	
	void Update ()
	{
		if(Input.GetKeyDown("[4]"))
			targetangle += deg45;
		if(Input.GetKeyDown("[6]"))
			targetangle -= deg45;

		//Move the camera left and right at a static speed, and update the target angle accordingly
		if(Input.GetKey("[4]"))
		{
			angle += deg*1.5f;
			if(angle > targetangle) targetangle += deg45;
		}
		else if(Input.GetKey("[6]"))
		{
			angle -= deg*1.5f;
			if(angle < targetangle) targetangle -= deg45;
		}

		//Move the camera toward/away from the player
		else if(Input.GetKey("[8]") && camera.orthographicSize > 3.5f)
		{
			camera.orthographicSize -= 0.1f;
			yoffset -= .025f;
		}
		else if(Input.GetKey("[2]") && camera.orthographicSize < 7f)
		{
			camera.orthographicSize += 0.1f;
			yoffset += .025f;
		}

		//If the current camera angle is too close to the target angle when key is released,
		//increment the target angle to avoid an abrupt stop
		if(Input.GetKeyUp("[4]") || Input.GetKeyUp("[6]"))
		{
			temp = targetangle - angle;
			if(Mathf.Abs(temp) < deg*15) targetangle += deg45*Mathf.Sign(temp);
		}
		
		updateCamera();
	}
	
	public void updateCamera()
	{
		//If the camera rotation keys are not being pressed,
		if(!Input.GetKey("[4]") && !Input.GetKey("[6]"))
		{
			if(angle != targetangle)
			{
				//Decelerate rotation toward target angle until it is reached
				//Rotation speed is capped at deg
				temp = (targetangle - angle) / 16f;
				if(Mathf.Abs(temp) > deg*1.5f) temp = deg*1.5f*Mathf.Sign(temp);
				angle += temp;
			}
			
			//Correct the floating point number when within a small range of the target angle
			if(angle < targetangle + 0.005f && angle > targetangle - 0.005f)
			{
				angle = targetangle;
				angle = keepInBounds(angle);
				targetangle = angle;
			}
		}
		
		//Follow Player
		point = target.transform.position;
		
		float xoffset = Mathf.Sin(angle) * distance;
		float zoffset = Mathf.Cos(angle) * distance;
		
		transform.position = new Vector3(point.x + xoffset, point.y + yoffset,
		                                 point.z + zoffset);
		transform.LookAt(new Vector3(point.x, point.y - 0.5f, point.z));
	}
	
	//Keeps the angle variable between 0 and pi*2
	public float keepInBounds(float a)
	{
		if(a < 0)
			a += twoPi;
		if(a > twoPi)
			a -= twoPi;
		
		return a;
	}
	
	//Returns a relative angle in Radians where "steps" is the number of
	//45 degree turns clockwise from "toward" the camera
	public float getDirection(int steps) 
	{
		return keepInBounds(this.angle + (deg45 * steps));
	}
	
	public float getAngle()
	{
		return angle;
	}
}