/*
 * @(#)EmbeddedApplicationInitializer.java
 *
 * Copyright 2010 Instituto Superior Tecnico
 * Founding Authors: Pedro Santos
 * 
 *      https://fenix-ashes.ist.utl.pt/
 * 
 *   This file is part of the Bennu-Vadin Integration Module.
 *
 *   The Bennu-Vadin Integration Module is free software: you can
 *   redistribute it and/or modify it under the terms of the GNU Lesser General
 *   Public License as published by the Free Software Foundation, either version 
 *   3 of the License, or (at your option) any later version.
 *
 *   The Bennu-Vadin Module 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 Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with the Bennu-Vadin Module. If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package pt.ist.bennu.vaadin;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.PatternSyntaxException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.io.IOUtils;

import pt.ist.bennu.core._development.PropertiesManager;
import pt.ist.bennu.vaadin.errorHandling.ReporterErrorWindow;
import pt.ist.fenixWebFramework.servlets.filters.contentRewrite.RequestChecksumFilter;
import pt.ist.fenixWebFramework.servlets.filters.contentRewrite.RequestChecksumFilter.ChecksumPredicate;
import pt.ist.fenixframework.artifact.FenixFrameworkArtifact;
import pt.ist.fenixframework.project.exception.FenixFrameworkProjectException;
import pt.ist.vaadinframework.EmbeddedApplication;
import pt.ist.vaadinframework.annotation.EmbeddedAnnotationProcessor;
import pt.ist.vaadinframework.annotation.EmbeddedComponent;
import pt.ist.vaadinframework.ui.EmbeddedComponentContainer;

@SuppressWarnings("serial")
/**
 * 
 * @author Pedro Santos
 * @author Sérgio Silva
 * @author João Marques
 * @author Luis Cruz
 * 
 */
public class EmbeddedApplicationInitializer extends HttpServlet {
    static {
        RequestChecksumFilter.registerFilterRule(new ChecksumPredicate() {
            @Override
            public boolean shouldFilter(HttpServletRequest httpServletRequest) {
                return !httpServletRequest.getRequestURI().endsWith("/vaadinContext.do");
            }
        });
    }

    private static final Set<Class<? extends EmbeddedComponentContainer>> embeddedComponentClasses =
            new HashSet<Class<? extends EmbeddedComponentContainer>>();

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);

        loadEmbeddedComponentsFromFile(embeddedComponentClasses);
        for (Class<? extends EmbeddedComponentContainer> embeddedComponentClass : embeddedComponentClasses) {
            EmbeddedComponent embeddedComponent = embeddedComponentClass.getAnnotation(EmbeddedComponent.class);
            if (embeddedComponent == null) {
                continue;
            }

            String[] paths = embeddedComponent.path();

            for (String path : paths) {
                try {
                    EmbeddedApplication.addPage(embeddedComponentClass);
                } catch (PatternSyntaxException e) {
                    throw new Error("Error interpreting pattern: " + path, e);
                }
            }
        }

        EmbeddedApplication.registerErrorWindow(new ReporterErrorWindow());
    }

    private void loadEmbeddedComponentsFromFile(final Set<Class<? extends EmbeddedComponentContainer>> embeddedComponentClasses) {
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        try {
            for (FenixFrameworkArtifact artifact : FenixFrameworkArtifact.fromName(PropertiesManager.getProperty("app.name"))
                    .getArtifacts()) {
                try (InputStream stream =
                        loader.getResourceAsStream(artifact.getName() + "/" + EmbeddedAnnotationProcessor.LOG_FILENAME)) {
                    if (stream != null) {
                        List<String> classnames = IOUtils.readLines(stream);
                        for (String classname : classnames) {
                            Class<? extends EmbeddedComponentContainer> type =
                                    (Class<? extends EmbeddedComponentContainer>) loader.loadClass(classname);
                            embeddedComponentClasses.add(type);
                        }
                    }
                }
            }
        } catch (IOException | ClassNotFoundException | FenixFrameworkProjectException e) {
            e.printStackTrace();
        }
    }
}