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

public class TimerController : MonoBehaviour
{
	private float _levelDuration; //you'd set this at the beginning of each level

	private Text timerText;
	private float startTime;
	private float currentTime;
	private bool timerActive;

	void Awake()
	{
		timerText = gameObject.GetComponent<Text>();
		if (timerText == null)
		{
			Debug.LogError("This script needs to be attached to a GUI text object!");
			this.enabled = false;
			return;
		}
	}

	void Update()
	{
		UpdateTimer();
	}

	public void SetTimer(float levelDuration)
	{
		_levelDuration = levelDuration;
		SetTimerString(levelDuration);
	}

	public void StartTimer()
	{
		timerActive = true;
		startTime = Time.time;
	}

	public void SetTimerActive(bool active)
	{
		timerActive = active;
	}

	void UpdateTimer()
	{
		if (!timerActive)
			return;

		float remainingTime = _levelDuration - (Time.time - startTime);
		if (remainingTime > 0.0f)
		{
			SetTimerString(remainingTime);
		}
		else
		{
			SetTimerString(0f);
			//do stuff here to trigger the end of the level
			//best to probably set a private variable in this class that can be read from another class via a method
		}
	}

	private void SetTimerString(float time)
	{
		//convert the time to the format you want to show - I'm not doing any formatting :P

		timerText.text = time.ToString();
	}

	public void AddToTimer(float time)
	{
		//either add to levelDuration or deduct from startTime doesn't matter - I choose deducting from the startTime because you might want to reference levelDUration later
		startTime += time;
	}
}