/* 
 * This file is part of the PDF Split And Merge source code
 * Created on 09/ott/2014
 * Copyright 2013-2014 by Andrea Vacondio (andrea.vacondio@gmail.com).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as 
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 *
 * This program 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 Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.pdfsam.ui.dialog;

import static org.apache.commons.lang3.ArrayUtils.isNotEmpty;
import static org.sejda.eventstudio.StaticStudio.eventStudio;

import java.io.File;

import javax.inject.Inject;
import javax.inject.Provider;

import org.pdfsam.i18n.DefaultI18nContext;
import org.pdfsam.module.TaskExecutionRequestEvent;
import org.sejda.eventstudio.annotation.EventListener;
import org.sejda.eventstudio.exception.BroadcastInterruptionException;
import org.sejda.injector.Auto;
import org.sejda.model.exception.TaskOutputVisitException;
import org.sejda.model.output.DirectoryTaskOutput;
import org.sejda.model.output.ExistingOutputPolicy;
import org.sejda.model.output.FileOrDirectoryTaskOutput;
import org.sejda.model.output.FileTaskOutput;
import org.sejda.model.output.TaskOutputDispatcher;
import org.sejda.model.parameter.base.AbstractParameters;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Controller receiving task execution requests and displaying the dialog if necessary
 * 
 * @author Andrea Vacondio
 *
 */
@Auto
public class OverwriteDialogController {
    private static final Logger LOG = LoggerFactory.getLogger(OverwriteDialogController.class);

    private Provider<OverwriteConfirmationDialog> dialog;

    @Inject
    public OverwriteDialogController(Provider<OverwriteConfirmationDialog> dialog) {
        this.dialog = dialog;
        eventStudio().addAnnotatedListeners(this);
    }

    @EventListener(priority = Integer.MIN_VALUE)
    public void request(TaskExecutionRequestEvent event) {
        AbstractParameters params = event.getParameters();
        try {
            if (params.getExistingOutputPolicy() != ExistingOutputPolicy.OVERWRITE) {
                event.getParameters().getOutput().accept(new TaskOutputDispatcher() {

                    @Override
                    public void dispatch(FileOrDirectoryTaskOutput output) {
                        onDirectory(params, output.getDestination());
                    }

                    @Override
                    public void dispatch(DirectoryTaskOutput output) {
                        onDirectory(params, output.getDestination());
                    }

                    @Override
                    public void dispatch(FileTaskOutput output) {
                        onFile(params, output.getDestination());
                    }

                });
            }
        } catch (TaskOutputVisitException e) {
            // it should never happen
            LOG.warn("Unable to show overwrite confirmation dialog", e);
        }
    }

    private void onDirectory(AbstractParameters params, File dir) {
        if (isNotEmpty(dir.listFiles())) {
            if (!dialog.get().title(DefaultI18nContext.getInstance().i18n("Directory not empty"))
                    .messageTitle(DefaultI18nContext.getInstance().i18n("The selected directory is not empty"))
                    .messageContent(DefaultI18nContext.getInstance()
                            .i18n("Overwrite files with the same name as the generated ones?"))
                    .response()) {
                throw new BroadcastInterruptionException(
                        DefaultI18nContext.getInstance().i18n("Don't overwrite existing file"));
            }
            LOG.trace("Enabling overwrite of the existing output file");
            params.setExistingOutputPolicy(ExistingOutputPolicy.OVERWRITE);
        }
    }

    private void onFile(AbstractParameters params, File file) {
        if (file.exists()) {
            if (!dialog.get().title(DefaultI18nContext.getInstance().i18n("Overwrite confirmation"))
                    .messageTitle(DefaultI18nContext.getInstance().i18n("A file with the given name already exists"))
                    .messageContent(DefaultI18nContext.getInstance().i18n("Do you want to overwrite it?")).response()) {
                throw new BroadcastInterruptionException(
                        DefaultI18nContext.getInstance().i18n("Don't overwrite existing file"));
            }
            LOG.trace("Enabling overwrite of the existing output file");
            params.setExistingOutputPolicy(ExistingOutputPolicy.OVERWRITE);
        }
    }
}
