using UnityEngine;
using System.Collections;

public class FadingMessage : MonoBehaviour 
{
    private string _message; // Message to be displayed
    private Rect _rectMessage; // Where to display the message on screen
    private Vector3 _location; // Where the message is being translated from in-world
    private Color _color; // Current color of the message (fades out)

    private float _timer; // Timer used to count down until our destruction
    private float _duration; // How long the message should take to fade out
    private float _height; // How high the message should rise while fading out

	
	void Update () 
    {
        // Decrement the fade timer
        _timer += Time.deltaTime;
        if(_timer < _duration)
        {
            // Update the color
            _color.a = 1 - (_timer / _duration);

            // Update the position
            Vector3 point = Camera.main.WorldToScreenPoint(_location);
            _rectMessage = new Rect(point.x - (GUIState.FadingMessageWidth / 2),
                (Screen.height - point.y) - (_timer * _height / _duration),
                GUIState.FadingMessageWidth, GUIState.MenuFontSize * 2);
        }
        else
        {
            // If we have exceeded the duration, it's time to destroy us!
            Destroy(gameObject);
        }
	}


    void OnGUI()
    {
        GUI.skin = GUIState.GuiSkin;

        // Ensure that this message is drawn over top of everything else
        GUI.depth = -1;

        // Update the color (fade out)
        GUI.color = _color;

        // Update font size and alignment
        GUI.skin.label.fontSize = GUIState.MenuFontSize;
        GUI.skin.label.alignment = TextAnchor.LowerCenter;

        // Actually draw the message on screen
        GUI.Label(_rectMessage, _message);
        
        // Reset the GUI's color so it doesn't leak into other GUI scripts
        GUI.color = Color.white;

        // Reset the label so it doesn't leak into other GUI scripts
        GUIState.ResetLabel();
    }


    public void NewMessage(string message, Vector3 location, Color color, float duration = 1, float height = 200)
    {
        _message = message;
        _location = location;
        _color = color;
        _duration = duration;
        _height = height;
    }
}