/**

  * 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.htmlpage;

 import java.io.IOException;

 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.bck2brwsr.core.JavaScriptBody;

 import org.json.JSONArray;

 import org.json.JSONException;

 import org.json.JSONObject;

 import org.json.JSONTokener;

 /**

  *

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

  */

 public final class ConvertTypes {

     ConvertTypes() {

     }

     public static String toString(Object object, String property) {

         Object ret = getProperty(object, property);

         return ret == null ? null : ret.toString();

     }

     public static double toDouble(Object object, String property) {

         Object ret = getProperty(object, property);

         return ret instanceof Number ? ((Number)ret).doubleValue() : Double.NaN;

     }

     public static int toInt(Object object, String property) {

         Object ret = getProperty(object, property);

         return ret instanceof Number ? ((Number)ret).intValue() : Integer.MIN_VALUE;

     }

     public static <T> T toModel(Class<T> modelClass, Object object, String property) {

         Object ret = getProperty(object, property);

         if (ret instanceof JSObject) {

             Object real = ((JSObject)ret).getMember("koModel");

             if (real != null) {

                 ret = real;

             }

         }

         if (ret == null || modelClass.isInstance(ret)) {

             return modelClass.cast(ret);

         }

         throw new IllegalStateException("Value " + ret + " is not of type " + modelClass);

     }

     public static String toJSON(Object value) {

         if (value == null) {

             return "null";

         }

         if (value instanceof String) {

             return '"' + 

                 ((String)value).

                     replace("\"", "\\\"").

                     replace("\n", "\\n").

                     replace("\r", "\\r").

                     replace("\t", "\\t")

                 + '"';

         }

         return value.toString();

     }

     @JavaScriptBody(args = { "object", "property" },

         body = "if (property === null) return object;\n"

         + "var p = object[property]; return p ? p : null;"

     )

     private static Object getProperty(Object object, String property) {

         if (property == null) {

             return object;

         } else {

             if (object instanceof JSObject) {

                 JSObject jo = (JSObject)object;

                 return jo.getMember(property);

             }

             return null;

         }

     }

     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"

         );

     }

     public static String createJSONP(Object[] jsonResult, Runnable whenDone) {

         return "json" + Integer.toHexString(whenDone.hashCode());

     }

     @JavaScriptBody(args = { "url", "jsonResult", "whenDone", "jsonp" }, body = "throw 'ignore';")

     public static void loadJSON(

         String url, Object[] jsonResult, Runnable whenDone, String jsonp

     ) {

         LoadJSON.REQ.execute(new LoadJSON(url, jsonResult, whenDone, jsonp));

     }

     private static final class LoadJSON implements Runnable {

         static final Executor REQ = Executors.newCachedThreadPool();

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

         private final String url;

         private final Object[] jsonResult;

         private final Runnable whenDone;

         private final String jsonp;

         private final URL base;

         LoadJSON(String url, Object[] jsonResult, Runnable whenDone, String jsonp) {

             this.url = url;

             this.jsonResult = jsonResult;

             this.whenDone = whenDone;

             this.jsonp = jsonp;

             URL b;

             try {

                 b = new URL(findBaseURL());

             } catch (MalformedURLException ex) {

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

                 b = null;

             }

             this.base = b;

         }

         @Override

         public void run() {

             if (Platform.isFxApplicationThread()) {

                 whenDone.run();

                 return;

             }

             try {

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

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

                 boolean array = false;

                 if (jsonp != null) {

                     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);

                 jsonResult[0] = convertToArray(obj);

             } catch (JSONException | IOException ex) {

                 jsonResult[0] = 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;

             }

         }

     }

     @JavaScriptBody(args = { "url", "jsonp" }, body = 

         "var scrpt = window.document.createElement('script');\n "

         + "scrpt.setAttribute('src', url);\n "

         + "scrpt.setAttribute('id', jsonp);\n "

         + "scrpt.setAttribute('type', 'text/javascript');\n "

         + "var body = document.getElementsByTagName('body')[0];\n "

         + "body.appendChild(scrpt);\n"

     )

     private static void loadJSONP(String url, String jsonp) {

     }

     @JavaScriptBody(args = { "jsonObject", "props", "values" }, body = "throw 'ignore extractJSON';")

     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);

                 }

             }

         }

     }

 }