import java.util.ArrayList;
import javax.swing.*;
import java.awt.event.*;
import java.lang.Math.*;
import java.text.DecimalFormat;


public class Resolver implements ActionListener {

    private JTextField[][] grid;
    private int GRID_SIZE;

    public Resolver(JTextField[][] grid, int GRID_SIZE) {

	this.grid = grid;
	this.GRID_SIZE = GRID_SIZE;
    }

    @Override

    public void actionPerformed(ActionEvent e) {

	resolution();
    }


    private void resolution() {

	long depart = System.nanoTime();

	ArrayList<JTextField> case_vide = new ArrayList<JTextField>();

	do {

	    for (int row = 0; row < this.GRID_SIZE; row++) {
		for (int col = 0; col < this.GRID_SIZE; col++) {

		    if (grid[row][col].getText().isEmpty()) {

			if (!case_vide.contains(grid[row][col])) {

			    case_vide.add(grid[row][col]);
			}

			//Création de la liste de chiffre acceptable
			ArrayList<String> chiffre_possible = new  ArrayList<String>();

			for (int i = 1; i <= GRID_SIZE; i++) {
			    chiffre_possible.add(""+i);
			}
		    
			//recherche des chiffres present sur la ligne
			for (int col2 = 0; col2 < this.GRID_SIZE; col2++) {

			    if (!grid[row][col2].getText().isEmpty()) {

				chiffre_possible.remove(""+grid[row][col2].getText());
			    }

			}

			//recherche des chiffres sur la colonne
			for (int row2 = 0; row2 < this.GRID_SIZE; row2++) {

			    if (!grid[row2][col].getText().isEmpty()) {

				chiffre_possible.remove(""+grid[row2][col].getText());
			    }

			}

			//recherche des chiffres dans la région
			int rowregion = row/3*3;
			int colregion = col/3*3;
			for (int row2 = rowregion; row2 < rowregion + 3; row2++) {
			    for (int col2 = colregion; col2 < colregion + 3; col2++) {

				if (!grid[row2][col2].getText().isEmpty()) {

				    chiffre_possible.remove(""+grid[row2][col2].getText());
				}
			    }
			}
			if (chiffre_possible.size() == 1) {

			    grid[row][col].setText(chiffre_possible.getFirst());

			    case_vide.remove(grid[row][col]);
			}
			    
		    }
		}
	    }
	}while (!case_vide.isEmpty());

	double durée = (((System.nanoTime()) - depart )* Math.pow(10,-9));
	DecimalFormat df = new DecimalFormat("0.00");
			
	JOptionPane.showMessageDialog(null, "Grille terminé en " + df.format(durée) + " secondes", "Résolution automatique", JOptionPane.INFORMATION_MESSAGE);
		    
		    
		
	    
    }
}