package zander.ui;

import java.awt.BorderLayout;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.io.PrintWriter;
import java.io.StringWriter;

import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingConstants;
import javax.swing.UIManager;

public class ErrorDialog extends JDialog {

    private static final long serialVersionUID = 7389430189757589219L;

    private Throwable error;

    private final JLabel iconLabel;
    private final JLabel messageLabel;
    private final JPanel messagePanel;
    private final JTextArea errorBox;
    private final JScrollPane errorScroll;
    private final JButton advancedButton;
    private final JButton closeButton;
    private final JPanel buttonPanel;
    private final JPanel content;

    public ErrorDialog(String title, String message, Throwable error) {
        this(null, title, message, error);
    }

    public ErrorDialog(Window parent, String title, String message, Throwable error) {
        super(parent, title);
        this.error = error;
        iconLabel = new JLabel(UIManager.getIcon("OptionPane.errorIcon"));
        messageLabel = new JLabel(message, SwingConstants.CENTER);
        messagePanel = new JPanel();
        messagePanel.setLayout(new BoxLayout(messagePanel, BoxLayout.X_AXIS));
        messagePanel.add(iconLabel);
        messagePanel.add(messageLabel);
        errorBox = new JTextArea(getErrorMessage());
        errorBox.setRows(getErrorBoxRows());
        errorBox.setColumns(getErrorBoxColumns());
        errorBox.setEditable(false);
        errorScroll = new JScrollPane(errorBox);
        errorScroll.setVisible(false);
        advancedButton = new JButton("Show More...");
        advancedButton.setMnemonic(KeyEvent.VK_S);
        advancedButton.addActionListener((e) -> {
                errorScroll.setVisible(!errorScroll.isVisible());
                pack();
            });
        closeButton = new JButton("Close");
        advancedButton.setMnemonic(KeyEvent.VK_C);
        closeButton.addActionListener((e) -> {
                dispose();
            });
        buttonPanel = new JPanel();
        buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.X_AXIS));
        buttonPanel.add(advancedButton);
        buttonPanel.add(Box.createHorizontalGlue());
        buttonPanel.add(closeButton);
        content = new JPanel(new BorderLayout());
        content.setLayout(new BorderLayout());
        content.add(messagePanel, BorderLayout.PAGE_START);
        content.add(errorScroll, BorderLayout.CENTER);
        content.add(buttonPanel, BorderLayout.PAGE_END);
        setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        setContentPane(content);
        setModalityType(JDialog.DEFAULT_MODALITY_TYPE);
        setAlwaysOnTop(true);
        pack();
        UIUtils.centerWindow(this, parent);
    }

    private int getErrorBoxRows() {
        int nlc = 0;
        for (char c : errorBox.getText().toCharArray()) {
            if (c == '\n') {
                ++nlc;
            }
        }
        return Math.min(nlc, 15);
    }

    private int getErrorBoxColumns() {
        String[] lines = errorBox.getText().split("\\n");
        int longest = 0;
        for (String line : lines) {
            if (line.length() > longest) {
                longest = line.length();
            }
        }
        return Math.min(longest, 35);
    }

    public String getMessage() {
        return messageLabel.getText();
    }

    public void setMessage(String message) {
        messageLabel.setText(message);
    }

    private String getErrorMessage() {
        if (error == null) {
            return "No error information available";
        }
        final StringWriter sw = new StringWriter();
        final PrintWriter pw = new PrintWriter(sw);
        error.printStackTrace(pw);
        return sw.toString();
    }

}