/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * This program 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, version 2 of the License.

 *

 * 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 General Public License

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.bck2brwsr.dew;

import java.io.IOException;

import java.io.InputStream;

import java.io.Writer;

import java.net.URI;

import java.net.URISyntaxException;

import java.net.URL;

import java.util.Arrays;

import java.util.Enumeration;

import java.util.LinkedHashSet;

import java.util.Set;

import java.util.logging.Level;

import java.util.logging.Logger;

import org.apidesign.vm4brwsr.Bck2Brwsr;

import org.glassfish.grizzly.PortRange;

import org.glassfish.grizzly.http.server.HttpHandler;

import org.glassfish.grizzly.http.server.HttpServer;

import org.glassfish.grizzly.http.server.NetworkListener;

import org.glassfish.grizzly.http.server.Request;

import org.glassfish.grizzly.http.server.Response;

import org.glassfish.grizzly.http.server.ServerConfiguration;

/**

 * Lightweight server to launch dew - the Development Environment for Web.

 */

final class DewLauncher {

    private static final Logger LOG = Logger.getLogger(DewLauncher.class.getName());

    private Set<ClassLoader> loaders = new LinkedHashSet<>();

    private Set<Bck2Brwsr.Resources> xRes = new LinkedHashSet<>();

    private final Res resources = new Res();

    private final String cmd;

    public DewLauncher(String cmd) {

        this.cmd = cmd;

    }

    public void addClassLoader(ClassLoader url) {

        this.loaders.add(url);

    }

    final HttpServer initServer(Bck2Brwsr.Resources... extraResources) {

        xRes.addAll(Arrays.asList(extraResources));

        HttpServer s = HttpServer.createSimpleServer(".", new PortRange(8080, 65535));

        final ServerConfiguration conf = s.getServerConfiguration();

        conf.addHttpHandler(new VM(resources), "/bck2brwsr.js");

        conf.addHttpHandler(new VMInit(), "/vm.js");

        conf.addHttpHandler(new Classes(resources), "/classes/");

        return s;

    }

    final Object[] launchServerAndBrwsr(HttpServer server, final String page) throws IOException, URISyntaxException, InterruptedException {

        server.start();

        NetworkListener listener = server.getListeners().iterator().next();

        int port = listener.getPort();

        URI uri = new URI("http://localhost:" + port + page);

        LOG.log(Level.INFO, "Showing {0}", uri);

        if (cmd == null) {

            try {

                LOG.log(Level.INFO, "Trying Desktop.browse on {0} {2} by {1}", new Object[] {

                    System.getProperty("java.vm.name"),

                    System.getProperty("java.vm.vendor"),

                    System.getProperty("java.vm.version"),

                });

                java.awt.Desktop.getDesktop().browse(uri);

                LOG.log(Level.INFO, "Desktop.browse successfully finished");

                return null;

            } catch (UnsupportedOperationException ex) {

                LOG.log(Level.INFO, "Desktop.browse not supported: {0}", ex.getMessage());

                LOG.log(Level.FINE, null, ex);

            }

        }

        {

            String cmdName = cmd == null ? "xdg-open" : cmd;

            String[] cmdArr = { 

                cmdName, uri.toString()

            };

            LOG.log(Level.INFO, "Launching {0}", Arrays.toString(cmdArr));

            final Process process = Runtime.getRuntime().exec(cmdArr);

            return new Object[] { process, null };

        }

    }

    private class Res implements Bck2Brwsr.Resources {

        @Override

        public InputStream get(String resource) throws IOException {

            for (ClassLoader l : loaders) {

                URL u = null;

                Enumeration<URL> en = l.getResources(resource);

                while (en.hasMoreElements()) {

                    u = en.nextElement();

                }

                if (u != null) {

                    return u.openStream();

                }

            }

            for (Bck2Brwsr.Resources r : xRes) {

                InputStream is = r.get(resource);

                if (is != null) {

                    return is;

                }

            }

            throw new IOException("Can't find " + resource);

        }

    }

    private static class VM extends HttpHandler {

        private final Res loader;

        public VM(Res loader) {

            this.loader = loader;

        }

        @Override

        public void service(Request request, Response response) throws Exception {

            response.setCharacterEncoding("UTF-8");

            response.setContentType("text/javascript");

            Bck2Brwsr.generate(response.getWriter(), loader);

        }

    }

    private static class VMInit extends HttpHandler {

        public VMInit() {

        }

        @Override

        public void service(Request request, Response response) throws Exception {

            response.setCharacterEncoding("UTF-8");

            response.setContentType("text/javascript");

            response.getWriter().append(

                "function ldCls(res) {\n"

                + "  var request = new XMLHttpRequest();\n"

                + "  request.open('GET', '/classes/' + res, false);\n"

                + "  request.send();\n"

                + "  var arr = eval('(' + request.responseText + ')');\n"

                + "  return arr;\n"

                + "}\n"

                + "var vm = new bck2brwsr(ldCls);\n");

        }

    }

    private static class Classes extends HttpHandler {

        private final Res loader;

        public Classes(Res loader) {

            this.loader = loader;

        }

        @Override

        public void service(Request request, Response response) throws Exception {

            String res = request.getHttpHandlerPath();

            if (res.startsWith("/")) {

                res = res.substring(1);

            }

            try (InputStream is = loader.get(res)) {

                response.setContentType("text/javascript");

                Writer w = response.getWriter();

                w.append("[");

                for (int i = 0;; i++) {

                    int b = is.read();

                    if (b == -1) {

                        break;

                    }

                    if (i > 0) {

                        w.append(", ");

                    }

                    if (i % 20 == 0) {

                        w.write("\n");

                    }

                    if (b > 127) {

                        b = b - 256;

                    }

                    w.append(Integer.toString(b));

                }

                w.append("\n]");

            } catch (IOException ex) {

                response.setError();

                response.setDetailMessage(ex.getMessage());

            }

        }

    }

}