/**

  * 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.kofx;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.InputStreamReader;

 import java.io.PushbackInputStream;

 import java.io.Reader;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.Iterator;

 import java.util.concurrent.Executor;

 import java.util.concurrent.Executors;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import javafx.application.Platform;

 import javafx.scene.web.WebEngine;

 import netscape.javascript.JSObject;

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

 import org.json.JSONArray;

 import org.json.JSONException;

 import org.json.JSONObject;

 import org.json.JSONTokener;

 import org.openide.util.Exceptions;

 /** This is an implementation package - just

  * include its JAR on classpath and use official {@link Context} API

  * to access the functionality.

  *

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

  */

 final class LoadJSON implements Runnable {

     private static final Logger LOG = FXContext.LOG;

     private static final Executor REQ = Executors.newCachedThreadPool();

     private final JSONCall call;

     private final URL base;

     private Throwable error;

     private Object json;

     private LoadJSON(JSONCall call) {

         this.call = call;

         URL b;

         try {

             b = new URL(findBaseURL());

         } catch (MalformedURLException ex) {

             LOG.log(Level.SEVERE, "Can't find base url for " + call.composeURL("dummy"), ex);

             b = null;

         }

         this.base = b;

     }

     public static void loadJSON(JSONCall call) {

         REQ.execute(new LoadJSON((call)));

     }

     @Override

     public void run() {

         if (Platform.isFxApplicationThread()) {

             if (error != null) {

                 call.notifyError(error);

             } else {

                 call.notifySuccess(json);

             }

             return;

         }

         final String url;

         if (call.isJSONP()) {

             url = call.composeURL("dummy");

         } else {

             url = call.composeURL(null);

         }

         try {

             final URL u = new URL(base, url.replace(" ", "%20"));

             final PushbackInputStream is = new PushbackInputStream(u.openStream(), 1);

             boolean array = false;

             if (call.isJSONP()) {

                 for (;;) {

                     int ch = is.read();

                     if (ch == -1) {

                         break;

                     }

                     if (ch == '[') {

                         is.unread(ch);

                         array = true;

                         break;

                     }

                     if (ch == '{') {

                         is.unread(ch);

                         break;

                     }

                 }

             } else {

                 int ch = is.read();

                 array = ch == '[';

                 is.unread(ch);

             }

             Reader r = new InputStreamReader(is, "UTF-8");

             JSONTokener tok = new JSONTokener(r);

             Object obj = array ? new JSONArray(tok) : new JSONObject(tok);

             json = convertToArray(obj);

         } catch (JSONException | IOException ex) {

             error = ex;

             LOG.log(Level.WARNING, "Cannot connect to " + url, ex);

         } finally {

             Platform.runLater(this);

         }

     }

     private 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;

         }

     }

     public static void extractJSON(Object jsonObject, String[] props, Object[] values) {

         if (jsonObject instanceof JSONObject) {

             JSONObject obj = (JSONObject)jsonObject;

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

                 try {

                     values[i] = obj.has(props[i]) ? obj.get(props[i]) : null;

                 } catch (JSONException ex) {

                     LoadJSON.LOG.log(Level.SEVERE, "Can't read " + props[i] + " from " + jsonObject, ex);

                 }

             }

         }

         if (jsonObject instanceof JSObject) {

             JSObject obj = (JSObject)jsonObject;

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

                 Object val = obj.getMember(props[i]);

                 values[i] = isDefined(val) ? val : null;

             }

         }

     }

     public static Object parse(InputStream is) throws IOException {

         try {

             InputStreamReader r = new InputStreamReader(is, "UTF-8");

             JSONTokener t = new JSONTokener(r);

             return new JSONObject(t);

         } catch (JSONException ex) {

             throw new IOException(ex);

         }

     }

     private static String findBaseURL() {

         WebEngine eng = (WebEngine) System.getProperties().get("webEngine");

         return (String) eng.executeScript(

             "var h;"

             + "if (!!window && !!window.location && !!window.location.href)\n"

             + "  h = window.location.href;\n"

             + "else "

             + "  h = null;"

             + "h\n");

     }

     private static boolean isDefined(Object val) {

         return !"undefined".equals(val);

     }

 }