/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 472784
 *******************************************************************************/
package org.eclipse.ui.dialogs;

import java.util.Arrays;
import java.util.List;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;

/**
 * The common superclass for wizard import and export pages.
 * <p>
 * This class is not intended to be subclassed outside of the workbench.
 * </p>
 * @noextend This class is not intended to be subclassed by clients.
 */
public abstract class WizardDataTransferPage extends WizardPage implements Listener, IOverwriteQuery {

    // constants
    protected static final int SIZING_TEXT_FIELD_WIDTH = 250;

	protected static final int COMBO_HISTORY_LENGTH = 20;

    /**
     * Creates a new wizard page.
     *
     * @param pageName the name of the page
     */
    protected WizardDataTransferPage(String pageName) {
        super(pageName);
    }

    /**
     * Adds an entry to a history, while taking care of duplicate history items
     * and excessively long histories.  The assumption is made that all histories
     * should be of length <code>WizardDataTransferPage.COMBO_HISTORY_LENGTH</code>.
     *
     * @param history the current history
     * @param newEntry the entry to add to the history
     */
    protected String[] addToHistory(String[] history, String newEntry) {
		java.util.ArrayList<String> l = new java.util.ArrayList<>(Arrays.asList(history));
        addToHistory(l, newEntry);
        String[] r = new String[l.size()];
        l.toArray(r);
        return r;
    }

    /**
     * Adds an entry to a history, while taking care of duplicate history items
     * and excessively long histories.  The assumption is made that all histories
     * should be of length <code>WizardDataTransferPage.COMBO_HISTORY_LENGTH</code>.
     *
     * @param history the current history
     * @param newEntry the entry to add to the history
     */
    protected void addToHistory(List history, String newEntry) {
        history.remove(newEntry);
        history.add(0, newEntry);

        // since only one new item was added, we can be over the limit
        // by at most one item
        if (history.size() > COMBO_HISTORY_LENGTH) {
			history.remove(COMBO_HISTORY_LENGTH);
		}
    }

    /**
     * Return whether the user is allowed to enter a new container name or just
     * choose from existing ones.
     * <p>
     * Subclasses must implement this method.
     * </p>
     *
     * @return <code>true</code> if new ones are okay, and <code>false</code>
     *  if only existing ones are allowed
     */
    protected abstract boolean allowNewContainerName();

    /**
     * Creates a new label with a bold font.
     *
     * @param parent the parent control
     * @param text the label text
     * @return the new label control
     */
    protected Label createBoldLabel(Composite parent, String text) {
        Label label = new Label(parent, SWT.NONE);
        label.setFont(JFaceResources.getBannerFont());
        label.setText(text);
        GridData data = new GridData();
        data.verticalAlignment = GridData.FILL;
        data.horizontalAlignment = GridData.FILL;
        label.setLayoutData(data);
        return label;
    }

    /**
     * Creates the import/export options group controls.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method does
     * nothing. Subclasses wishing to define such components should reimplement
     * this hook method.
     * </p>
     *
     * @param optionsGroup the parent control
     */
    protected void createOptionsGroupButtons(Group optionsGroup) {
    }

    /**
     * Creates a new label with a bold font.
     *
     * @param parent the parent control
     * @param text the label text
     * @return the new label control
     */
    protected Label createPlainLabel(Composite parent, String text) {
        Label label = new Label(parent, SWT.NONE);
        label.setText(text);
        label.setFont(parent.getFont());
        GridData data = new GridData();
        data.verticalAlignment = GridData.FILL;
        data.horizontalAlignment = GridData.FILL;
        label.setLayoutData(data);
        return label;
    }

    /**
     * Creates a horizontal spacer line that fills the width of its container.
     *
     * @param parent the parent control
     */
    protected void createSpacer(Composite parent) {
        Label spacer = new Label(parent, SWT.NONE);
        GridData data = new GridData();
        data.horizontalAlignment = GridData.FILL;
        data.verticalAlignment = GridData.BEGINNING;
        spacer.setLayoutData(data);
    }

    /**
     * Returns whether this page is complete. This determination is made based upon
     * the current contents of this page's controls.  Subclasses wishing to include
     * their controls in this determination should override the hook methods
     * <code>validateSourceGroup</code> and/or <code>validateOptionsGroup</code>.
     *
     * @return <code>true</code> if this page is complete, and <code>false</code> if
     *   incomplete
     * @see #validateSourceGroup
     * @see #validateOptionsGroup
     */
    protected boolean determinePageCompletion() {
        boolean complete = validateSourceGroup() && validateDestinationGroup()
                && validateOptionsGroup();

        // Avoid draw flicker by not clearing the error
        // message unless all is valid.
        if (complete) {
			setErrorMessage(null);
		}

        return complete;
    }

    /**
     * Get a path from the supplied text widget.
     * @return org.eclipse.core.runtime.IPath
     */
    protected IPath getPathFromText(Text textField) {
        String text = textField.getText();
        //Do not make an empty path absolute so as not to confuse with the root
        if (text.length() == 0) {
			return new Path(text);
		}

        return (new Path(text)).makeAbsolute();
    }

    /**
     * Queries the user to supply a container resource.
     *
     * @return the path to an existing or new container, or <code>null</code> if the
     *    user cancelled the dialog
     */
    protected IPath queryForContainer(IContainer initialSelection, String msg) {
        return queryForContainer(initialSelection, msg, null);
    }

    /**
     * Queries the user to supply a container resource.
     *
     * @return the path to an existing or new container, or <code>null</code> if the
     *    user cancelled the dialog
     */
    protected IPath queryForContainer(IContainer initialSelection, String msg,
            String title) {
        ContainerSelectionDialog dialog = new ContainerSelectionDialog(
                getControl().getShell(), initialSelection,
                allowNewContainerName(), msg);
        if (title != null) {
			dialog.setTitle(title);
		}
        dialog.showClosedProjects(false);
        dialog.open();
        Object[] result = dialog.getResult();
        if (result != null && result.length == 1) {
            return (IPath) result[0];
        }
        return null;
    }

    /**
     * The <code>WizardDataTransfer</code> implementation of this
     * <code>IOverwriteQuery</code> method asks the user whether the existing
     * resource at the given path should be overwritten.
     *
     * @param pathString
     * @return the user's reply: one of <code>"YES"</code>, <code>"NO"</code>, <code>"ALL"</code>,
     *   or <code>"CANCEL"</code>
     */
    @Override
	public String queryOverwrite(String pathString) {

        Path path = new Path(pathString);

        String messageString;
        //Break the message up if there is a file name and a directory
        //and there are at least 2 segments.
        if (path.getFileExtension() == null || path.segmentCount() < 2) {
			messageString = NLS.bind(IDEWorkbenchMessages.WizardDataTransfer_existsQuestion, pathString);
		} else {
			messageString = NLS.bind(IDEWorkbenchMessages.WizardDataTransfer_overwriteNameAndPathQuestion, path.lastSegment(),
			path.removeLastSegments(1).toOSString());
		}

        final MessageDialog dialog = new MessageDialog(getContainer()
                .getShell(), IDEWorkbenchMessages.Question,
                null, messageString, MessageDialog.QUESTION, 0,
                        IDialogConstants.YES_LABEL,
                        IDialogConstants.YES_TO_ALL_LABEL,
                        IDialogConstants.NO_LABEL,
                        IDialogConstants.NO_TO_ALL_LABEL,
                        IDialogConstants.CANCEL_LABEL) {
        	@Override
			protected int getShellStyle() {
        		return super.getShellStyle() | SWT.SHEET;
        	}
        };
        String[] response = new String[] { YES, ALL, NO, NO_ALL, CANCEL };
        //run in syncExec because callback is from an operation,
        //which is probably not running in the UI thread.
        getControl().getDisplay().syncExec(() -> dialog.open());
        return dialog.getReturnCode() < 0 ? CANCEL : response[dialog
                .getReturnCode()];
    }

    /**
     * Displays a Yes/No question to the user with the specified message and returns
     * the user's response.
     *
     * @param message the question to ask
     * @return <code>true</code> for Yes, and <code>false</code> for No
     */
    protected boolean queryYesNoQuestion(String message) {
        MessageDialog dialog = new MessageDialog(getContainer().getShell(),
                IDEWorkbenchMessages.Question,
                (Image) null, message, MessageDialog.NONE, 0,
				IDEWorkbenchMessages.WizardDataTransfer_overwrite_button_label, IDialogConstants.CANCEL_LABEL) { // $NON-NLS-1$
        	@Override
			protected int getShellStyle() {
        		return super.getShellStyle() | SWT.SHEET;
        	}
        };
        // ensure yes is the default

        return dialog.open() == 0;
    }

    /**
     * Restores control settings that were saved in the previous instance of this
     * page.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method does
     * nothing. Subclasses may override this hook method.
     * </p>
     */
    protected void restoreWidgetValues() {
    }

    /**
     * Saves control settings that are to be restored in the next instance of
     * this page.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method does
     * nothing. Subclasses may override this hook method.
     * </p>
     */
    protected void saveWidgetValues() {
    }

    /**
     * Determine if the page is complete and update the page appropriately.
     */
    protected void updatePageCompletion() {
        boolean pageComplete = determinePageCompletion();
        setPageComplete(pageComplete);
        if (pageComplete) {
            setErrorMessage(null);
        }
    }

    /**
     * Updates the enable state of this page's controls.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method does
     * nothing. Subclasses may extend this hook method.
     * </p>
     */
    protected void updateWidgetEnablements() {
    }

    /**
     * Returns whether this page's destination specification controls currently all
     * contain valid values.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method returns
     * <code>true</code>. Subclasses may reimplement this hook method.
     * </p>
     *
     * @return <code>true</code> indicating validity of all controls in the
     *   destination specification group
     */
    protected boolean validateDestinationGroup() {
        return true;
    }

    /**
     * Returns whether this page's options group's controls currently all contain
     * valid values.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method returns
     * <code>true</code>. Subclasses may reimplement this hook method.
     * </p>
     *
     * @return <code>true</code> indicating validity of all controls in the options
     *   group
     */
    protected boolean validateOptionsGroup() {
        return true;
    }

    /**
     * Returns whether this page's source specification controls currently all
     * contain valid values.
     * <p>
     * The <code>WizardDataTransferPage</code> implementation of this method returns
     * <code>true</code>. Subclasses may reimplement this hook method.
     * </p>
     *
     * @return <code>true</code> indicating validity of all controls in the
     *   source specification group
     */
    protected boolean validateSourceGroup() {
        return true;
    }

    /**
     *	Create the options specification widgets.
     *
     *	@param parent org.eclipse.swt.widgets.Composite
     */
    protected void createOptionsGroup(Composite parent) {
        // options group
        Group optionsGroup = new Group(parent, SWT.NONE);
        GridLayout layout = new GridLayout();
        optionsGroup.setLayout(layout);
        optionsGroup.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL
                | GridData.GRAB_HORIZONTAL));
        optionsGroup.setText(IDEWorkbenchMessages.WizardExportPage_options);
        optionsGroup.setFont(parent.getFont());

        createOptionsGroupButtons(optionsGroup);

    }

    /**
     * Display an error dialog with the specified message.
     *
     * @param message the error message
     */
    protected void displayErrorDialog(String message) {
        MessageDialog.open(MessageDialog.ERROR, getContainer().getShell(),
                getErrorDialogTitle(), message, SWT.SHEET);
    }

    /**
     * Display an error dislog with the information from the
     * supplied exception.
     * @param exception Throwable
     */
    protected void displayErrorDialog(Throwable exception) {
        String message = exception.getMessage();
        //Some system exceptions have no message
        if (message == null) {
			message = NLS.bind(IDEWorkbenchMessages.WizardDataTransfer_exceptionMessage, exception);
		}
        displayErrorDialog(message);
    }

    /**
     * Get the title for an error dialog. Subclasses should
     * override.
     */
    protected String getErrorDialogTitle() {
        return IDEWorkbenchMessages.WizardExportPage_internalErrorTitle;
    }

}
