package ui.gui;

import model.asn1.ASN1Object;
import model.asn1.UtcTime;
import model.pki.cert.Certificate;
import model.pki.crl.Reason;
import model.pki.crl.RevokedCertificate;
import ui.gui.widgets.GCBuilder;
import ui.gui.widgets.UIUtils;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Arrays;

import static java.awt.GridBagConstraints.HORIZONTAL;
import static java.awt.GridBagConstraints.WEST;
import static ui.gui.widgets.UIUtils.alert;

/**
 * A dialog that presents user with cert info, revocation reason, and revocation time.
 * +----------------------------+
 * |Revoking: CN=xyz (Serial: 1)|
 * |Reason:   (Drop Down)       |
 * |Time:     (ISO-8601 text)   |
 * |                            |
 * |               Revoke Cancel|
 * +----------------------------+
 */
public class RevokeDialog extends JDialog {
    /**
     * ISO8601
     */
    private static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ISO_OFFSET_DATE_TIME;

    /**
     * The incoming certificate.
     */
    private final Certificate crt;

    /**
     * The result.
     */
    private RevokedCertificate res;


    /**
     * Root pane
     */
    private JPanel contentPane;

    /**
     * OK button
     */
    private JButton buttonOK;

    /**
     * Cancel button
     */
    private JButton buttonCancel;

    /**
     * Reason
     */
    private JComboBox<String> comboBoxReason;

    /**
     * Subject (not editable)
     */
    private JTextField textFieldSubject;

    /**
     * Time
     */
    private JFormattedTextField formattedTextFieldTime;

    /**
     * EFFECTS: Init GUI with the given cert.
     */
    public RevokeDialog(Certificate crt) {
        this.crt = crt;

        contentPane = new JPanel();
        contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.PAGE_AXIS));
        contentPane.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
        contentPane.add(renderForm());

        contentPane.add(UIUtils.createActionsPane(buttonOK = new JButton("Revoke"),
                        buttonCancel = new JButton("Cancel")));
        buttonOK.addActionListener(this::onOK);
        buttonCancel.addActionListener(this::onCancel);

        setContentPane(contentPane);
        setModal(true);
        getRootPane().setDefaultButton(buttonOK);
        setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);

        setTitle("Revoke certificate");

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                onCancel(null);
            }
        });

        contentPane.registerKeyboardAction(this::onCancel,
                KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0),
                JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
    }

    /**
     * EFFECTS: Init GUI.
     * MODIFIES: this
     */
    private JPanel renderForm() {
        final JPanel panelForm = new JPanel();
        panelForm.setLayout(new GridBagLayout());

        panelForm.add(new JLabel("Revoking: "), new GCBuilder().anchor(WEST).build());
        panelForm.add(new JLabel("Reason: "), new GCBuilder().gridY(1).anchor(WEST).build());
        panelForm.add(new JLabel("Time: "), new GCBuilder().gridY(2).anchor(WEST).build());

        textFieldSubject = new JTextField(String.format("%s (Serial: %d)",
                crt.getCertificate().getSubject().toString(), crt.getCertificate().getSerialNumber().getLong()));
        textFieldSubject.setEditable(false);
        panelForm.add(textFieldSubject, new GCBuilder().gridX(1).anchor(WEST).fill(HORIZONTAL).build());

        comboBoxReason = new JComboBox<>(Arrays.stream(Reason.values()).map(Enum::toString).toArray(String[]::new));
        panelForm.add(comboBoxReason, new GCBuilder().gridXY(1, 1).anchor(WEST).fill(HORIZONTAL).build());

        formattedTextFieldTime = new JFormattedTextField(DATE_FORMAT.toFormat());
        formattedTextFieldTime.setText(ZonedDateTime.now().format(DATE_FORMAT));
        panelForm.add(formattedTextFieldTime, new GCBuilder().gridXY(1, 2).anchor(WEST).fill(HORIZONTAL).build());

        panelForm.add(new JPanel(), new GCBuilder().gridXY(1, 3).expandXY().fill(HORIZONTAL).build());
        return panelForm;
    }

    /**
     * EFFECTS: Validate form, set result, and close dialog.
     *          Time must be a valid ISO-8601 string with offset, and it will be converted into UTC.
     *          Reason must be supported.
     * MODIFIES: this
     */
    private void onOK(ActionEvent ev) {
        try {
            res = new RevokedCertificate(ASN1Object.TAG_SEQUENCE, null,
                    crt.getCertificate().getSerialNumber(),
                    new UtcTime(UtcTime.TAG, null,
                            ZonedDateTime.parse(formattedTextFieldTime.getText(), DATE_FORMAT)
                                    .withZoneSameInstant(ZoneId.of("UTC"))),
                    Reason.valueOf(comboBoxReason.getSelectedItem().toString()));
            dispose();
        } catch (DateTimeParseException e) {
            alert(rootPane, "Revoke certificate", "Invalid time: " + formattedTextFieldTime.getText()
                    + ". It must be a valid ISO8601 time with offset, like '1919-08-10T11:45:14+09:00'.");
        } catch (IllegalArgumentException e) {
            alert(rootPane, "Revoke certificate", "Invalid reason.");
        }
    }

    /**
     * EFFECTS: Clear the result and close dialog.
     * MODIFIES: this
     */
    private void onCancel(ActionEvent ev) {
        res = null;
        dispose();
    }

    /**
     * EFFECTS: Get result.
     */
    public RevokedCertificate getRes() {
        return res;
    }
}