/*
 * Copyright (c) 2010, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.grizzly.http.server;

import java.io.File;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.glassfish.grizzly.Grizzly;
import org.glassfish.grizzly.http.Method;
import org.glassfish.grizzly.http.util.Header;
import org.glassfish.grizzly.http.util.HttpStatus;
import org.glassfish.grizzly.utils.ArraySet;

HttpHandler, which processes requests to a static resources. 
Author:
Jeanfrancois Arcand, Alexey Stashok/**
 * {@link HttpHandler}, which processes requests to a static resources.
 *
 * @author Jeanfrancois Arcand
 * @author Alexey Stashok
 */
public class StaticHttpHandler extends StaticHttpHandlerBase {
    private static final Logger LOGGER = Grizzly.logger(StaticHttpHandler.class);

    protected final ArraySet<File> docRoots = new ArraySet<>(File.class);

    private boolean directorySlashOff;

    
Create HttpHandler, which, by default, will handle requests to the static resources located in the current
directory.
/**
     * Create <tt>HttpHandler</tt>, which, by default, will handle requests to the static resources located in the current
     * directory.
     */
    public StaticHttpHandler() {
        addDocRoot(".");
    }

    
Create a new instance which will look for static pages located under the docRoot. If the docRoot is
null - static pages won't be served by this HttpHandler
Params:
docRoots – the folder(s) where the static resource are located. If the docRoot is null -
static pages won't be served by this HttpHandler/**
     * Create a new instance which will look for static pages located under the <tt>docRoot</tt>. If the <tt>docRoot</tt> is
     * <tt>null</tt> - static pages won't be served by this <tt>HttpHandler</tt>
     *
     * @param docRoots the folder(s) where the static resource are located. If the <tt>docRoot</tt> is <tt>null</tt> -
     * static pages won't be served by this <tt>HttpHandler</tt>
     */
    public StaticHttpHandler(String... docRoots) {
        if (docRoots != null) {
            for (String docRoot : docRoots) {
                addDocRoot(docRoot);
            }
        }
    }

    
Create a new instance which will look for static pages located under the docRoot. If the docRoot is
null - static pages won't be served by this HttpHandler
Params:
docRoots – the folders where the static resource are located. If the docRoot is empty - static pages
won't be served by this HttpHandler/**
     * Create a new instance which will look for static pages located under the <tt>docRoot</tt>. If the <tt>docRoot</tt> is
     * <tt>null</tt> - static pages won't be served by this <tt>HttpHandler</tt>
     *
     * @param docRoots the folders where the static resource are located. If the <tt>docRoot</tt> is empty - static pages
     * won't be served by this <tt>HttpHandler</tt>
     */
    @SuppressWarnings("UnusedDeclaration")
    public StaticHttpHandler(Set<String> docRoots) {
        if (docRoots != null) {
            for (String docRoot : docRoots) {
                addDocRoot(docRoot);
            }
        }
    }

    
Return the default directory from where files will be serviced.
Returns:
the default directory from where file will be serviced./**
     * Return the default directory from where files will be serviced.
     * 
     * @return the default directory from where file will be serviced.
     */
    @SuppressWarnings("UnusedDeclaration")
    public File getDefaultDocRoot() {
        final File[] array = docRoots.getArray();
        return array != null && array.length > 0 ? array[0] : null;
    }

    
Return the list of directories where files will be serviced from.
Returns:
the list of directories where files will be serviced from./**
     * Return the list of directories where files will be serviced from.
     *
     * @return the list of directories where files will be serviced from.
     */
    public ArraySet<File> getDocRoots() {
        return docRoots;
    }

    
Add the directory to the list of directories where files will be serviced from.
Params:
docRoot – the directory to be added to the list of directories where files will be serviced from.
Returns:
return the File representation of the passed docRoot./**
     * Add the directory to the list of directories where files will be serviced from.
     *
     * @param docRoot the directory to be added to the list of directories where files will be serviced from.
     *
     * @return return the {@link File} representation of the passed <code>docRoot</code>.
     */
    public final File addDocRoot(String docRoot) {
        if (docRoot == null) {
            throw new NullPointerException("docRoot can't be null");
        }

        final File file = new File(docRoot);
        addDocRoot(file);

        return file;
    }

    
Add the directory to the list of directories where files will be serviced from.
Params:
docRoot – the directory to be added to the list of directories where files will be serviced from./**
     * Add the directory to the list of directories where files will be serviced from.
     *
     * @param docRoot the directory to be added to the list of directories where files will be serviced from.
     */
    public final void addDocRoot(File docRoot) {
        docRoots.add(docRoot);
    }

    
Removes the directory from the list of directories where static files will be serviced from.
Params:
docRoot – the directory to remove./**
     * Removes the directory from the list of directories where static files will be serviced from.
     *
     * @param docRoot the directory to remove.
     */
    @SuppressWarnings("UnusedDeclaration")
    public void removeDocRoot(File docRoot) {
        docRoots.remove(docRoot);
    }

    
Returns:
true if HTTP 301 redirect shouldn't be sent when requested static resource is a directory, or
false otherwise/**
     * @return <tt>true</tt> if HTTP 301 redirect shouldn't be sent when requested static resource is a directory, or
     * <tt>false</tt> otherwise
     */
    public boolean isDirectorySlashOff() {
        return directorySlashOff;
    }

    
If the directorySlashOff is true HTTP 301 redirect will not be sent when requested static resource is a
directory.
Params:
directorySlashOff – /**
     * If the directorySlashOff is <tt>true</tt> HTTP 301 redirect will not be sent when requested static resource is a
     * directory.
     *
     * @param directorySlashOff
     */
    public void setDirectorySlashOff(boolean directorySlashOff) {
        this.directorySlashOff = directorySlashOff;
    }

    // ------------------------------------------------------- Protected Methods

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    protected boolean handle(final String uri, final Request request, final Response response) throws Exception {

        boolean found = false;

        final File[] fileFolders = docRoots.getArray();
        if (fileFolders == null) {
            return false;
        }

        File resource = null;

        for (int i = 0; i < fileFolders.length; i++) {
            final File webDir = fileFolders[i];
            // local file
            resource = new File(webDir, uri);
            final boolean exists = resource.exists();
            final boolean isDirectory = resource.isDirectory();

            if (exists && isDirectory) {

                if (!directorySlashOff && !uri.endsWith("/")) { // redirect to the same url, but with trailing slash
                    response.setStatus(HttpStatus.MOVED_PERMANENTLY_301);
                    response.setHeader(Header.Location, response.encodeRedirectURL(uri + "/"));
                    return true;
                }

                final File f = new File(resource, "/index.html");
                if (f.exists()) {
                    resource = f;
                    found = true;
                    break;
                }
            }

            if (isDirectory || !exists) {
                found = false;
            } else {
                found = true;
                break;
            }
        }

        if (!found) {
            if (LOGGER.isLoggable(Level.FINE)) {
                LOGGER.log(Level.FINE, "File not found {0}", resource);
            }
            return false;
        }

        assert resource != null;

        // If it's not HTTP GET - return method is not supported status
        if (!Method.GET.equals(request.getMethod())) {
            if (LOGGER.isLoggable(Level.FINE)) {
                LOGGER.log(Level.FINE, "File found {0}, but HTTP method {1} is not allowed", new Object[] { resource, request.getMethod() });
            }
            response.setStatus(HttpStatus.METHOD_NOT_ALLOWED_405);
            response.setHeader(Header.Allow, "GET");
            return true;
        }

        pickupContentType(response, resource.getPath());

        addToFileCache(request, response, resource);
        sendFile(response, resource);

        return true;
    }
}