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package org.netbeans.modules.selenium2.webclient.protractor;

import java.io.File;
import java.util.Collection;
import java.util.Collections;
import java.util.prefs.PreferenceChangeEvent;
import java.util.prefs.PreferenceChangeListener;
import javax.swing.event.ChangeListener;
import org.netbeans.api.project.Project;
import org.netbeans.modules.selenium2.webclient.protractor.preferences.ProtractorPreferences;
import org.netbeans.modules.selenium2.webclient.protractor.preferences.ProtractorPreferencesValidator;
import org.netbeans.modules.web.common.api.ValidationResult;
import org.netbeans.modules.web.common.spi.ImportantFilesImplementation;
import org.netbeans.spi.project.ProjectServiceProvider;
import org.openide.filesystems.FileObject;
import org.openide.filesystems.FileUtil;
import org.openide.util.ChangeSupport;
import org.openide.util.WeakListeners;

@ProjectServiceProvider(service = ImportantFilesImplementation.class, projectType = "org-netbeans-modules-web-clientproject") // NOI18N
public final class ImportantFilesImpl implements ImportantFilesImplementation, PreferenceChangeListener {

    private final Project project;
    private final ChangeSupport changeSupport = new ChangeSupport(this);

    // @GuardedBy("this")
    private boolean listening = false;


    public ImportantFilesImpl(Project project) {
        assert project != null;
        this.project = project;
    }

    private synchronized void addListener(Project project) {
        if (listening) {
            return;
        }
        ProtractorPreferences.addPreferenceChangeListener(project, WeakListeners.create(PreferenceChangeListener.class, this, ProtractorPreferences.class));
        listening = true;
    }

    @Override
    public Collection<FileInfo> getFiles() {
        addListener(project);
        if (!ProtractorPreferences.isEnabled(project)) {
            return Collections.emptyList();
        }
        String config = ProtractorPreferences.getUserConfigurationFile(project);
        ValidationResult result = new ProtractorPreferencesValidator()
                .validateUserConfigurationFile(project, config)
                .getResult();
        if (!result.isFaultless()) {
            return Collections.emptyList();
        }
        FileObject file = FileUtil.toFileObject(new File(config));
        assert file != null : config;
        return Collections.singleton(new FileInfo(file));
    }

    @Override
    public void addChangeListener(ChangeListener listener) {
        changeSupport.addChangeListener(listener);
    }

    @Override
    public void removeChangeListener(ChangeListener listener) {
        changeSupport.removeChangeListener(listener);
    }

    @Override
    public void preferenceChange(PreferenceChangeEvent evt) {
        String key = evt.getKey();
        if (ProtractorPreferences.ENABLED.equals(key)
                || ProtractorPreferences.USER_CONFIGURATION_FILE.equals(key)) {
            changeSupport.fireChange();
        }
    }

}
