using UnityEngine;
using System.Collections;

public class TouchInput : MonoBehaviour
{
    public struct TouchState
    {
        public int touchCount;
        public Vector2 Position;
        public Vector2 deltaPosition;
        public SwipeDirection swipeDirection;

        public void update()
        {
            touchCount = Input.touchCount;
            if (touchCount > 0)
            {
                Position = Input.GetTouch(0).position;
                deltaPosition = Input.GetTouch(0).deltaPosition;
                swipeDirection = TouchInput.getSwipeDirection(this);
            }
            else
            {
                Position = Vector2.zero;
                deltaPosition = Vector2.zero;
                swipeDirection = SwipeDirection.NONE;
            }
        }

    }

    static TouchState[] TouchStateSamples = new TouchState[_touchInputSamples];

    private static int _touchInputSamples = 16;
    public static int TouchInputSamples
    {
        get { return _touchInputSamples; }
        set { _touchInputSamples = value; TouchStateSamples = new TouchState[value]; }
    }
    private static int sampleCount = 0;

    public static TouchState GetTouchState()
    {
        TouchState currentTouchState = new TouchState();
        currentTouchState.update();

        sampleCount++;
        if (sampleCount >= _touchInputSamples)
        {
            sampleCount = 0;
            TouchStateSamples = new TouchState[_touchInputSamples];
        }

        TouchStateSamples[sampleCount] = currentTouchState;

        Vector2 avarageDelta = Vector2.zero;
        int collectedSamples = 0;
        for (int i = 0; i < _touchInputSamples; i++)
        {
            if (TouchStateSamples[i].Position != null )
            {
                avarageDelta += TouchStateSamples[i].deltaPosition;
                
                collectedSamples++;
            }
        }

        avarageDelta /= collectedSamples;

        currentTouchState.deltaPosition = avarageDelta;


        currentTouchState.swipeDirection = getSwipeDirection(currentTouchState);
        return currentTouchState;

    }
    public enum SwipeDirection
    {
        LEFT,
        RIGHT,
        DOWN,
        UP,
        LEFTUP,
        RIGHTUP,
        LEFTDOWN,
        RIGHTDOWN,
        NONE
    }

    // Use this for initialization
    void Start()
    {
        TouchStateSamples = new TouchState[_touchInputSamples];
    }

    // Update is called once per frame
    void Update()
    {

    }

    public static SwipeDirection getSwipeDirection(TouchState touchState)
    {
        if (Input.touchCount < 1)
        {
            return SwipeDirection.NONE;
        }

        float angle = Vector2ToAngle(touchState.deltaPosition);

        if (angle == 0)
        {
            return SwipeDirection.NONE;
        }

        if (angle > 2.5f && angle < 3.5f)
        {
            return SwipeDirection.RIGHT;
        }
        else if (angle > -1.5f && angle < 1.5f)
        {
            return SwipeDirection.LEFT;
        }

        return SwipeDirection.NONE;
    }

    static float Vector2ToAngle(Vector2 point)
    {
        return (float)Mathf.Atan2(point.y, point.x);
    }
}