package lab.art;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;

public class Generator 
{
    public static void main(String[] args) 
    {
	// create a (pseudo) random number generator
	Random random = new Random(System.currentTimeMillis());
	
	// generate a random expression for red, green and blue
	Expression redExpression = Expressions.getRandom(random);
	System.out.printf("Red: %s%n", redExpression);
	Expression greenExpression = Expressions.getRandom(random);
	System.out.printf("Green: %s%n", greenExpression);
	Expression blueExpression = Expressions.getRandom(random);
	System.out.printf("Blue: %s%n", blueExpression);
	
	// create an "empty" image
	final int PIXELS = 800;
	BufferedImage image = new BufferedImage(PIXELS, PIXELS, BufferedImage.TYPE_INT_RGB);
	
	// set each pixel to an amount of red, green and blue based on the expressions
	final int MAX = 255; // maximal value of each color
	for (int xCoordinate = 0; xCoordinate < PIXELS; xCoordinate++)
	{
	    for (int yCoordinate = 0; yCoordinate < PIXELS; yCoordinate++)
	    {
		// map [0, PIXELS) to [-1, 1]
		double x = 2 * xCoordinate / (double) PIXELS - 1;
		double y = 2 * yCoordinate / (double) PIXELS - 1;
		
		// evaluate red, green and blue
		double redValue = redExpression.evaluate(x, y);
		double greenValue = greenExpression.evaluate(x, y);
		double blueValue = blueExpression.evaluate(x, y);
			
		// map [-1, 1] to [0, MAX]
		int red = (int) (MAX * (1 + redValue) / 2.0);
		int green = (int) (MAX * (1 + greenValue) / 2.0);
		int blue = (int) (MAX * (1 + blueValue) / 2.0);
			
		// set the color of the pixel
		Color color = new Color(red, green, blue);
		image.setRGB(xCoordinate, yCoordinate, color.getRGB());
	    }
	    }
	
	// write the image to file
	File file = new File("Art.jpg");
	try 
	{
	    ImageIO.write(image, "JPEG", file);
	    System.out.println("Image generated");
	} 
	catch (IOException e) 
	{
	    System.out.println("Image generation failed");
	}
    }
}