using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class ProgressBar : MonoBehaviour {

    private float progress;
    private float maxAmount;

    public Image progressImage;
    public bool useTimer;
	public Color maxProgressColour;
	public Color minProgressColour;

    private Color currentColour;
    private float timeDuration = 100;    //In seconds
    private WaitForSeconds oneSecond = new WaitForSeconds(1);

	// Use this for initialization
	void Start () {
        progress = maxAmount;
		ChangeColour ();
	}

    public void DecrementProgress(float p) {
		if (progress > 0) {
			progress -= p;
			progressImage.fillAmount = (progress / maxAmount);
			ChangeColour ();
		} else {
			ProgressComplete ();
		}
    }

    public void SetMaxAmount(float m) {
        maxAmount = m;
		progress = m;
		progressImage.fillAmount = 1;
    }

    public void StartTimer() {
        if (useTimer) {
            float increment = maxAmount / timeDuration;
            StartCoroutine(StartTimer(increment));
        }
    }

    IEnumerator StartTimer(float increment) {
        while (true) {
            if(progress > 0) {
                yield return oneSecond;
                progress -= increment;
            } else {
				ProgressComplete ();
                break;
            }
        }
    }

	void ChangeColour(){
		progressImage.color = Color.Lerp (minProgressColour, maxProgressColour, (float)progress / maxAmount);
	}

	void ProgressComplete(){
		SendMessageUpwards ("OnProgressComplete");
	}
}