import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
 * The Health Bar class is one that helps the user track the
 * overall hp of the given target 
 * 
 * @author Prayan Jegathees 
 * @version March 2020
 */


public class PJHpBar extends Actor
{
    // instance variables
    private int hp;
    
    // 
    private int value;
    private int minimumVal = 0;
    private int maximumVal;
    private int minValue;
    private int maxValue;
    
    // HP bar dimensions
    private int hpBarWidth = 140;
    private int hpBarHeight = 24;
    
    // image variable names
    private GreenfootImage bar;
    private GreenfootImage border;
    
    // bar colors
    private Color healthyColor = Color.GREEN; 
    private Color midColor = Color.ORANGE;
    private Color dangerColor = Color.RED;
    
    // chunk removed from HP bar when health is decreased
    private int hpPerHit;
    
    // target for HP bar to follow & how far above to attach the bar
    private Actor target;
    private int offset; 
    
    /**
     * Default Constructor for the PJHpBar class, creating a functioning HP Bar
     * 
     * @param hp            takes in a value for the amount of HP the target has and what to display on the HP Bar
     * @param maximumVal    takes in a value for the maximum value of the bar
     * 
     */
    public PJHpBar(int hp,int maximumVal)
    {
        bar = new GreenfootImage(hpBarWidth, hpBarHeight);
        bar.setColor(healthyColor);
        bar.fill();
        
        bar.setColor (Color.BLACK);
        bar.drawRect (0, 0, hpBarWidth - 2, hpBarHeight -2);
        
        this.setImage(bar);
               
        minValue = minimumVal;
        maxValue = maximumVal;
        this.hp = hp;
        hpPerHit  = (int) ((double)hpBarWidth / hp);
    }
    
    /**
     * Act - do whatever the PJHealthBar wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        update();
    }    
    
    /**
     * Update - adjust bar hp color based on the current hp of the target
     * <p>
     *  - Green if the target's health is between 100% and 75%
     * <p>
     *  - Orange if the target's health is between 35% and 74%
     * <p>
     *  - Red if the target's health is below 35%
     */
    public void update()
    {
        int percentHealth = ((hp / maxValue) * 100);
        if (percentHealth >= 75)
        {
            bar.setColor(healthyColor);
        }
        if (35 <=  percentHealth && percentHealth <= 74)
        {
            bar.setColor(midColor);
        }
        if (0 <= percentHealth && percentHealth <= 34)
        {
            bar.setColor(dangerColor);
        }
    }
    
    /**
     * Add - add an amount to the value of the bar, checks to make sure the new value is between minimumValue and maximumValue,
     * then, calls 'newImage' to build and set the new image for the bar.
     *
     * @param amount - the amount to add (if not negative) or subtract (if negative) to the current value of the bar
     */
    public void add(int amount)
    {
        value += amount;
        protectValue();
    }
    
    /**
     * Subtract - subtracts an amount from the value of the bar, checks to make sure the new value does not overstep its bounds,
     * then, calls 'updBarImage' to build and set the new image for the bar.
     *
     * @param amount - the amount to subtract (if positive) or add (if negative) to the current value of the bar
     */
    public void loseHP(int amount)
    {
        value -= amount;
        protectValue();
    }
    
    /**
     * Method protectValue - ensures that the new value in between the minimum value and the maximum value for the bar
     */
    private void protectValue()
    {
        if (value < minValue) 
        {
            value = minValue;
        }
        
        if (value > maxValue) 
        {
            value = maxValue;
        }
    }
}