import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.util.Scanner;
import javax.swing.JOptionPane;

/**
 * A class to open files for input/output after prompting for the file name
 *
 * @author Bill Kraynek
 */
public class OpenFiles {

    /**
     * Prompts the user for a file name and opens the file for input @returns a
     * Scanner object to read the file
     */
    public static Scanner getNameAndOpenInput() throws IOException {
        int tries = 1;
        String fileName;
        while (true) {
            fileName = JOptionPane.showInputDialog("Enter the input file name");
            try {
                return new Scanner(new File(fileName));
            } catch(NullPointerException e) {
                return null;
            } catch (IOException e) {
                if (tries > 2) {
                    throw e;
                }
                JOptionPane.showMessageDialog(null, fileName + " could not be opened. Try again.");
                tries++;
                if (tries == 3) {
                    JOptionPane.showMessageDialog(null, "This is your last try!");
                }
            } // try/catch
        } // end while
    } // end getNameAndOpenInput

    /**
     * Prompts the user for a file name and opens the file for output
     *
     * @return the opened file
     */
    public static FileWriter getNameAndOpenOutput() throws IOException {
        String fileName;
        int tries = 1;
        while (true) {
            fileName = JOptionPane.showInputDialog("Enter the output file name");
            try {
                return new FileWriter(fileName);
            } catch(NullPointerException e) {
                return null;
            } catch (IOException e) {
                if (tries > 2) {
                    throw e;
                }
                JOptionPane.showMessageDialog(null, fileName + " could not be opened. Try again.");
                tries++;
                if (tries == 3) {
                    JOptionPane.showMessageDialog(null, "This is your last try!");
                }
            } // try/catch
        } // end while
    } // end getNameAndOpenOutput
} // end OpenFiles