/*
 * This file is part of muCommander, http://www.mucommander.com
 *
 * muCommander is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * muCommander is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.mucommander.ui.action.impl;

import java.io.IOException;
import java.net.MalformedURLException;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import com.mucommander.bookmark.BookmarkManager;
import com.mucommander.commons.file.AbstractFile;
import com.mucommander.commons.file.FileURL;
import com.mucommander.commons.file.protocol.local.LocalFile;
import com.mucommander.conf.MuConfigurations;
import com.mucommander.conf.MuPreference;
import com.mucommander.conf.MuPreferences;
import com.mucommander.core.desktop.DesktopManager;
import com.mucommander.desktop.ActionType;
import com.mucommander.job.impl.TempExecJob;
import com.mucommander.text.Translator;
import com.mucommander.ui.action.AbstractActionDescriptor;
import com.mucommander.ui.action.ActionCategory;
import com.mucommander.ui.action.ActionDescriptor;
import com.mucommander.ui.action.ActionManager;
import com.mucommander.ui.action.MuAction;
import com.mucommander.ui.action.NoIcon;
import com.mucommander.ui.dialog.InformationDialog;
import com.mucommander.ui.dialog.file.ProgressDialog;
import com.mucommander.ui.main.FolderPanel;
import com.mucommander.ui.main.MainFrame;
import com.mucommander.ui.main.quicklist.RecentExecutedFilesQL;
import com.mucommander.ui.main.tabs.FileTableTabs;

/**
 * This action 'opens' the currently selected file or folder in the active FileTable. This means different things
 * depending on the kind of file that is currently selected:
 * <ul>
 * <li>For browsable files (directory, archive...): shows file contents
 * <li>For local file that are not an archive or archive entry: executes file with native file associations
 * <li>For any other file type, remote or local: copies file to a temporary local file and executes it with native file
 * associations
 * </ul>
 *
 * @author Maxence Bernard, Nicolas Rinaudo
 */
public class OpenAction extends MuAction {
    /**
     * Creates a new <code>OpenAction</code> with the specified parameters.
     * 
     * @param mainFrame
     *            frame to which the action is attached.
     * @param properties
     *            action's properties.
     */
    public OpenAction(MainFrame mainFrame, Map<String, Object> properties) {
        super(mainFrame, properties);
    }

    /**
     * Opens the specified file in the specified folder panel.
     * <p>
     * <code>file</code> will be opened using the following rules:
     * <ul>
     * <li>If <code>file</code> is {@link com.mucommander.commons.file.AbstractFile#isBrowsable() browsable}, it will be
     * opened in <code>destination</code>.</li>
     * <li>If <code>file</code> is local, it will be opened using its native associations.</li>
     * <li>If <code>file</code> is remote, it will first be copied in a temporary local file and then opened using its
     * native association.</li>
     * </ul>
     * </p>
     * 
     * @param file
     *            file to open.
     * @param destination
     *            if <code>file</code> is browsable, folder panel in which to open the file.
     */
    protected void open(AbstractFile file, FolderPanel destination) {
        AbstractFile resolvedFile;
        if (file.isSymlink()) {
            resolvedFile = resolveSymlink(file);

            if (resolvedFile == null) {
                InformationDialog.showErrorDialog(mainFrame.getJFrame(), Translator.get("cannot_open_cyclic_symlink"));
                return;
            }
        } else
            resolvedFile = file;

        // Opens browsable files in the destination FolderPanel.
        if (resolvedFile.isBrowsable()) {
            resolvedFile = MuConfigurations.getPreferences()
                    .getVariable(MuPreference.CD_FOLLOWS_SYMLINKS, MuPreferences.DEFAULT_CD_FOLLOWS_SYMLINKS)
                            ? resolvedFile
                            : file;
            FileTableTabs tabs = destination.getTabs();

            if (BookmarkManager.isBookmark(resolvedFile.getURL())) {
                String bookmarkLocation = BookmarkManager.getBookmark(resolvedFile.getName()).getLocation();
                FileURL bookmarkURL;
                try {
                    bookmarkURL = FileURL.getFileURL(bookmarkLocation);
                } catch (MalformedURLException e) {
                    LOGGER.error("Failed to resolve bookmark's location: " + bookmarkLocation);
                    return;
                }

                if (tabs.getCurrentTab().isLocked())
                    tabs.add(bookmarkURL);
                else
                    destination.tryChangeCurrentFolder(bookmarkURL);
            } else {
                if (tabs.getCurrentTab().isLocked())
                    tabs.add(resolvedFile);
                else
                    destination.tryChangeCurrentFolder(resolvedFile);
            }
        }

        // Opens local files using their native associations.
        else if (resolvedFile.getURL().getScheme().equals(LocalFile.SCHEMA)
                && (resolvedFile.hasAncestor(LocalFile.class))) {
            try {
                OpenAction.openFile(getMainFrame(), resolvedFile);
                RecentExecutedFilesQL.addFile(resolvedFile);
            } catch (IOException e) {
                InformationDialog.showErrorDialog(mainFrame.getJFrame());
            }
        }

        // Copies non-local file in a temporary local file and opens them using their native association.
        else {
            ProgressDialog progressDialog = new ProgressDialog(mainFrame, Translator.get("copy_dialog.copying"));
            TempExecJob job = new TempExecJob(progressDialog, mainFrame, resolvedFile);
            progressDialog.start(job);
        }
    }

    protected AbstractFile resolveSymlink(AbstractFile symlink) {
        return resolveSymlink(symlink, new HashSet<AbstractFile>());
    }

    private AbstractFile resolveSymlink(AbstractFile file, Set<AbstractFile> visitedFiles) {
        if (visitedFiles.contains(file))
            return null;
        else {
            visitedFiles.add(file);
            return file.isSymlink() ? resolveSymlink(file.getCanonicalFile(), visitedFiles) : file;
        }
    }

    /**
     * Opens the currently selected file in the active folder panel.
     */
    @Override
    public void performAction() {
        // Retrieves the currently selected file.
        // Note: a CachedFile instance is retrieved to avoid blocking the event thread.
        AbstractFile file = mainFrame.getActiveTable().getSelectedFile(true, true);

        // Aborts if none.
        if (file == null)
            return;

        // Opens the currently selected file.
        open(file, mainFrame.getActivePanel());

    }

    /**
     * Brings up an opening file error dialog with the output message and a generic localized title if and only if the
     * task that opens the given file provides an output message and the user preference
     * {@code MuPreference.VIEW_ON_ERROR} has not been enabled.
     * <p>
     * In case the user preference {@code MuPreference.VIEW_ON_ERROR} has been enabled, the viewer will automatically be
     * launched to open the file.
     *
     * @param mainFrame
     *            determines the <code>Frame</code> in which the dialog is displayed
     * @param file
     *            the file to open.
     */
    public static void openFile(MainFrame mainFrame, AbstractFile file)
            throws IOException, UnsupportedOperationException {
        DesktopManager.open(file)
                .thenAccept(
                        outputMessages -> outputMessages.ifPresent(
                                s -> {
                                    if (MuConfigurations.getPreferences()
                                            .getVariable(MuPreference.VIEW_ON_ERROR,
                                                    MuPreferences.DEFAULT_VIEW_ON_ERROR)) {
                                        ActionManager.getActionInstance(ActionType.View, mainFrame).performAction();
                                    } else {
                                        InformationDialog.showErrorDialog(mainFrame.getJFrame(), s);
                                    }
                                }));
    }

    @Override
    public ActionDescriptor getDescriptor() {
        return new Descriptor();
    }

    @NoIcon
    public static class Descriptor extends AbstractActionDescriptor {
        public String getId() {
            return ActionType.Open.getId();
        }

        public ActionCategory getCategory() {
            return ActionCategory.NAVIGATION;
        }
    }
}
