package org.opentrafficsim.demo.ntm.IO;

import java.awt.Component;
import java.awt.Container;
import java.io.File;

import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
import javax.swing.UIManager;
import javax.swing.filechooser.FileFilter;

/**
 * The FileDialog class is (or rather should) be used for all file dialogs in Open Traffic
 * @author Peter Knoppers
 */
public class FileDialog
{
    /**
     * Show a file selector dialog to the user.
     * @param reading boolean; set to true if only existing files may be selected, set to false if a non-existing file may be
     *            returned and new directories may be created. If reading is false and an existing file is selected that is not
     *            equal to the defaultName, an overwrite warning dialog will be displayed.
     * @param fileType String; expected file type
     * @param fileTypeDescription String; description of expected file type
     * @param defaultName String; path to directory shown initially in the file selector dialog; if it ends on an existing file
     *            name, that file is initially selected
     * @return String; absolute path of the selected file (or null when the operation was cancelled by the user)
     */
    public static String showFileDialog(boolean reading, String fileType, String fileTypeDescription, String defaultName)
    {
        FileFilter filter = new ExtensionFileFilter(fileTypeDescription, fileType);
        javax.swing.JFileChooser fileChooser = new JFileChooser();
        if (!fileType.isEmpty())
        {
            fileChooser.setFileFilter(filter);
        }
        File defaultFile = new File(defaultName);
        fileChooser.setCurrentDirectory(defaultFile);
        if (defaultFile.isFile())
        {
            fileChooser.setSelectedFile(defaultFile);
            fileChooser.ensureFileIsVisible(defaultFile);
        }
        int result;
        if (reading)
        {
            disableNewFolderButton(fileChooser);
            fileChooser.setDialogType(JFileChooser.OPEN_DIALOG);
            result = fileChooser.showOpenDialog(null);
        }
        else
        {
            fileChooser.setDialogType(JFileChooser.SAVE_DIALOG);
            result = fileChooser.showSaveDialog(null);
        }
        if (JFileChooser.APPROVE_OPTION == result)
        {
            String fullName = fileChooser.getSelectedFile().getAbsolutePath();
            if (null == fullName)
                return null;
            String plainName = fileChooser.getSelectedFile().getName();
            int dotPosition = plainName.lastIndexOf(".");
            if ((dotPosition < 0) && (!reading))
                fullName += "." + fileType;
            if ((!reading) && (!defaultName.equals(fullName)) && (new File(fullName).exists()))
                if (JOptionPane.showConfirmDialog(null, String.format("Overwrite existing file \"%s\"?", fullName),
                        "Overwrite file", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE) != JOptionPane.YES_OPTION)
                    return null;
            return fullName;
        }
        return null;
    }

    // adapted from
    // http://www.java2s.com/Code/Java/Swing-JFC/DisabletheJFileChoosersNewfolderbutton.htm
    // Search a tree of Containers recursively for a JButton with the newFolderIcon and
    // call setEnabled(false) for that/those button(s). There should be a cleaner way...
    private static void disableNewFolderButton(Container c)
    {
        for (Component comp : c.getComponents())
        {
            if (comp instanceof JButton)
            {
                JButton b = (JButton) comp;
                Icon icon = b.getIcon();
                if ((null != icon) && (icon == UIManager.getIcon("FileChooser.newFolderIcon")))
                    b.setEnabled(false);
            }
            else if (comp instanceof Container)
                disableNewFolderButton((Container) comp);
        }
    }

}

// adapted from http://www.java2s.com/Code/JavaAPI/javax.swing/JFileChoosersetFileFilterFileFilterfilter.htm
class ExtensionFileFilter extends FileFilter
{
    String description;

    String extensions[];

    public ExtensionFileFilter(String description, String extension)
    {
        this(description, new String[] {extension});
    }

    public ExtensionFileFilter(String description, String extensions[])
    {
        if (description == null)
            this.description = extensions[0];
        else
            this.description = description;
        this.extensions = extensions.clone();
        toLower(this.extensions);
    }

    private static void toLower(String array[])
    {
        for (int i = 0, n = array.length; i < n; i++)
            array[i] = array[i].toLowerCase();
    }

    @Override
    public String getDescription()
    {
        return description;
    }

    @Override
    public boolean accept(File file)
    {
        if (file.isDirectory())
            return true;
        String path = file.getAbsolutePath().toLowerCase();
        for (int i = 0, n = extensions.length; i < n; i++)
        {
            String extension = extensions[i];
            if ((path.endsWith(extension) && (path.charAt(path.length() - extension.length() - 1)) == '.'))
                return true;
        }
        return false;
    }

}