/*******************************************************************************
 * Copyright (C) 2011, Mathias Kinzler <mathias.kinzler@sap.com>
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *******************************************************************************/
package org.eclipse.egit.ui.internal.fetch;

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.egit.core.op.ListRemoteOperation;
import org.eclipse.egit.ui.Activator;
import org.eclipse.egit.ui.UIPreferences;
import org.eclipse.egit.ui.UIUtils;
import org.eclipse.egit.ui.internal.UIText;
import org.eclipse.jface.dialogs.IMessageProvider;
import org.eclipse.jface.dialogs.ProgressMonitorDialog;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.transport.RemoteConfig;
import org.eclipse.jgit.transport.URIish;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;

/**
 * Obtain the Fetch Source, i.e. the {@link Ref} on the remote
 * {@link Repository}
 */
public class FetchSourcePage extends WizardPage {
	private final Repository repository;

	private final RemoteConfig config;

	private Text sourceText;

	private List<Ref> remoteRefs;

	/**
	 * Default constructor
	 *
	 * @param repository
	 * @param config
	 */
	public FetchSourcePage(Repository repository, RemoteConfig config) {
		super(FetchSourcePage.class.getName());
		this.repository = repository;
		this.config = config;
		setTitle(UIText.FetchSourcePage_PageTitle);
	}

	@Override
	public void createControl(Composite parent) {
		Composite main = new Composite(parent, SWT.NONE);
		main.setLayout(new GridLayout(2, false));
		GridDataFactory.fillDefaults().grab(true, true).applyTo(main);

		Label repositoryLabel = new Label(main, SWT.NONE);
		repositoryLabel.setText(UIText.FetchSourcePage_RepositoryLabel);
		Text repositoryText = new Text(main, SWT.READ_ONLY | SWT.BORDER);
		repositoryText.setText(config.getURIs().get(0).toPrivateString());
		GridDataFactory.fillDefaults().grab(true, false)
				.applyTo(repositoryText);

		Label sourceLabel = new Label(main, SWT.NONE);
		sourceLabel.setText(UIText.FetchSourcePage_SourceLabel);
		sourceText = new Text(main, SWT.BORDER);
		sourceText.addModifyListener(new ModifyListener() {
			@Override
			public void modifyText(ModifyEvent e) {
				checkPage();
			}
		});
		GridDataFactory.fillDefaults().grab(true, false).applyTo(sourceText);
		UIUtils.addRefContentProposalToText(sourceText, repository,
				() -> getRemoteRefs());
		checkPage();
		setControl(main);
	}

	private void checkPage() {
		setMessage(null, IMessageProvider.WARNING);
		setErrorMessage(null);
		setMessage(UIText.FetchSourcePage_PageMessage);
		if (sourceText.getText().length() == 0) {
			setPageComplete(false);
			return;
		}
		boolean found = false;
		for (Ref ref : getRemoteRefs()) {
			if (ref.getName().equals(sourceText.getText()))
				found = true;
		}
		if (!found)
			setMessage(NLS.bind(UIText.FetchSourcePage_RefNotFoundMessage,
					sourceText.getText()), IMessageProvider.WARNING);
		setPageComplete(true);
	}

	@Override
	public void setVisible(boolean visible) {
		super.setVisible(visible);
		if (visible)
			sourceText.setFocus();
	}

	/**
	 * @return the source
	 */
	public String getSource() {
		return sourceText.getText();
	}

	private List<Ref> getRemoteRefs() {
		if (remoteRefs == null) {
			URIish uriToCheck;
			List<Ref> proposals = new ArrayList<>();
			uriToCheck = config.getURIs().get(0);
			final ListRemoteOperation lop = new ListRemoteOperation(repository,
					uriToCheck, Activator.getDefault().getPreferenceStore()
							.getInt(UIPreferences.REMOTE_CONNECTION_TIMEOUT));
			try {
				new ProgressMonitorDialog(getShell()).run(true, true,
						new IRunnableWithProgress() {
							@Override
							public void run(IProgressMonitor monitor)
									throws InvocationTargetException,
									InterruptedException {
								monitor
										.beginTask(
												UIText.FetchSourcePage_GettingRemoteRefsTaskname,
												IProgressMonitor.UNKNOWN);
								lop.run(monitor);
								monitor.done();
							}
						});
				for (Ref ref : lop.getRemoteRefs()) {
					if (ref.getName().startsWith(Constants.R_HEADS)
							|| ref.getName().startsWith(Constants.R_TAGS))
						proposals.add(ref);
				}
				Collections.sort(proposals, new Comparator<Ref>() {
					@Override
					public int compare(Ref o1, Ref o2) {
						return o1.getName().compareTo(o2.getName());
					}
				});
				this.remoteRefs = proposals;
			} catch (IllegalStateException e) {
				setErrorMessage(e.getMessage());
			} catch (InvocationTargetException e) {
				setErrorMessage(e.getMessage());
			} catch (InterruptedException e) {
				setErrorMessage(e.getMessage());
			}
		}
		return remoteRefs;
	}
}