/**

 * HTML via Java(tm) Language Bindings

 * Copyright (C) 2013 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. apidesign.org

 * designates this particular file as subject to the

 * "Classpath" exception as provided by apidesign.org

 * in the License file that accompanied this code.

 *

 * 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://wiki.apidesign.org/wiki/GPLwithClassPathException

 */

package org.apidesign.html.wstyrus;

import java.io.IOException;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.Iterator;

import javax.websocket.ClientEndpoint;

import javax.websocket.ContainerProvider;

import javax.websocket.DeploymentException;

import javax.websocket.OnClose;

import javax.websocket.OnError;

import javax.websocket.OnMessage;

import javax.websocket.OnOpen;

import javax.websocket.Session;

import javax.websocket.WebSocketContainer;

import net.java.html.json.OnReceive;

import org.apidesign.html.context.spi.Contexts;

import org.apidesign.html.json.spi.JSONCall;

import org.apidesign.html.json.spi.WSTransfer;

import org.apidesign.html.wstyrus.TyrusContext.Comm;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import org.json.JSONTokener;

import org.openide.util.lookup.ServiceProvider;

/** This is an implementation module that provides support for

 * WebSocket protocol for {@link OnReceive} communication end point for

 * JDK7.

 * <p>

 * Don't deal with this module directly, rather use the 

 * {@link OnReceive @OnReceive(url="ws://...", ...)} API to establish your

 * WebSocket connection.

 * <p>

 * There is no need to include this module in your application if you are

 * running on JDK8. JDK8 WebView provides its own implementation of the

 * WebSocket API based on WebSocket object inside a browser. This is included

 * in the <code>org.apidesign.html:ko-fx:0.5</code> module.

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

@ServiceProvider(service = Contexts.Provider.class)

public final class TyrusContext implements Contexts.Provider, WSTransfer<Comm> {

    @Override

    public void fillContext(Contexts.Builder context, Class<?> requestor) {

        // default WebSocket transfer implementation is registered

        // in ko-fx module with 100, provide this one as a fallback only

        context.register(WSTransfer.class, this, 1000);

    }

    @Override

    public Comm open(String url, JSONCall callback) {

        try {

            return new Comm(new URI(url), callback);

        } catch (URISyntaxException ex) {

            throw new IllegalStateException(ex);

        }

    }

    @Override

    public void send(Comm socket, JSONCall data) {

        socket.session.getAsyncRemote().sendText(data.getMessage());

    }

    @Override

    public void close(Comm socket) {

        try {

            socket.session.close();

        } catch (IOException ex) {

            socket.callback.notifyError(ex);

        }

    }

    /** Implementation class in an implementation. Represents a {@link ClientEndpoint} of the

     * WebSocket channel. You are unlikely to get on hold of it.

     */

    @ClientEndpoint

    public static final class Comm {

        private final JSONCall callback;

        private Session session;

        Comm(final URI url, JSONCall callback) {

            this.callback = callback;

            try {

                final WebSocketContainer c = ContainerProvider.getWebSocketContainer();

                c.connectToServer(Comm.this, url);

            } catch (DeploymentException | IOException ex) {

                wasAnError(ex);

            }

        }

        @OnOpen

        public synchronized void open(Session s) {

            this.session = s;

            callback.notifySuccess(null);

        }

        @OnClose

        public void close() {

            this.session = null;

            callback.notifyError(null);

        }

        @OnMessage

        public void message(final String orig, Session s) {

            Object json;

            String data = orig.trim();

            try {

                JSONTokener tok = new JSONTokener(data);

                Object obj = data.startsWith("[") ? new JSONArray(tok) : new JSONObject(tok);

                json = convertToArray(obj);

            } catch (JSONException ex) {

                json = data;

            }

            callback.notifySuccess(json);

        }

        @OnError

        public void wasAnError(Throwable t) {

            callback.notifyError(t);

        }

        static Object convertToArray(Object o) throws JSONException {

            if (o instanceof JSONArray) {

                JSONArray ja = (JSONArray) o;

                Object[] arr = new Object[ja.length()];

                for (int i = 0; i < arr.length; i++) {

                    arr[i] = convertToArray(ja.get(i));

                }

                return arr;

            } else if (o instanceof JSONObject) {

                JSONObject obj = (JSONObject) o;

                Iterator it = obj.keys();

                while (it.hasNext()) {

                    String key = (String) it.next();

                    obj.put(key, convertToArray(obj.get(key)));

                }

                return obj;

            } else {

                return o;

            }

        }

    } // end of Comm

}