/**

  * 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.ko2brwsr;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.InputStreamReader;

 import org.apidesign.bck2brwsr.core.JavaScriptBody;

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

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

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

 /**

  *

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

  */

 final class BrwsrCtxImpl implements Transfer, WSTransfer<LoadWS> {

     private BrwsrCtxImpl() {}

     public static final BrwsrCtxImpl DEFAULT = new BrwsrCtxImpl();

     @Override

     public void extract(Object obj, String[] props, Object[] values) {

         extractJSON(obj, props, values);

     }

     @Override

     public void loadJSON(final JSONCall call) {

         class R implements Runnable {

             final boolean success;

             public R(boolean success) {

                 this.success = success;

             }

             Object[] arr = { null };

             @Override

             public void run() {

                 if (success) {

                     call.notifySuccess(arr[0]);

                 } else {

                     Throwable t;

                     if (arr[0] instanceof Throwable) {

                         t = (Throwable) arr[0];

                     } else {

                         if (arr[0] == null) {

                             t = new IOException();

                         } else {

                             t = new IOException(arr[0].toString());

                         }

                     }

                     call.notifyError(t);

                 }

             }

         }

         R success = new R(true);

         R failure = new R(false);

         if (call.isJSONP()) {

             String me = createJSONP(success.arr, success);

             loadJSONP(call.composeURL(me), me);

         } else {

             String data = null;

             if (call.isDoOutput()) {

                 try {

                     ByteArrayOutputStream bos = new ByteArrayOutputStream();

                     call.writeData(bos);

                     data = new String(bos.toByteArray(), "UTF-8");

                 } catch (IOException ex) {

                     call.notifyError(ex);

                 }

             }

             loadJSON(call.composeURL(null), success.arr, success, failure, call.getMethod(), data);

         }

     }

     @Override

     public Object toJSON(InputStream is) throws IOException {

         StringBuilder sb = new StringBuilder();

         InputStreamReader r = new InputStreamReader(is);

         for (;;) {

             int ch = r.read();

             if (ch == -1) {

                 break;

             }

             sb.append((char)ch);

         }

         return parse(sb.toString());

     }

     @Override

     public LoadWS open(String url, JSONCall callback) {

         return new LoadWS(callback, url);

     }

     @Override

     public void send(LoadWS socket, JSONCall data) {

         socket.send(data);

     }

     @Override

     public void close(LoadWS socket) {

         socket.close();

     }

     //

     // implementations

     //

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

         body

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

         + "if (object === null) return null;\n"

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

     )

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

         return null;

     }

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

         int h = whenDone.hashCode();

         String name;

         for (;;) {

             name = "jsonp" + Integer.toHexString(h);

             if (defineIfUnused(name, jsonResult, whenDone)) {

                 return name;

             }

             h++;

         }

     }

     @JavaScriptBody(args = {"name", "arr", "run"}, body

         = "if (window[name]) return false;\n "

         + "window[name] = function(data) {\n "

         + "  delete window[name];\n"

         + "  var el = window.document.getElementById(name);\n"

         + "  el.parentNode.removeChild(el);\n"

         + "  arr[0] = data;\n"

         + "  run.run__V();\n"

         + "};\n"

         + "return true;\n"

     )

     private static boolean defineIfUnused(String name, Object[] arr, Runnable run) {

         return true;

     }

     @JavaScriptBody(args = {"s"}, body = "return eval('(' + s + ')');")

     static Object parse(String s) {

         return s;

     }

     @JavaScriptBody(args = {"url", "arr", "callback", "onError", "method", "data"}, body = ""

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

         + "if (!method) method = 'GET';\n"

         + "request.open(method, url, true);\n"

         + "request.setRequestHeader('Content-Type', 'application/json; charset=utf-8');\n"

         + "request.onreadystatechange = function() {\n"

         + "  if (this.readyState!==4) return;\n"

         + "  try {\n"

         + "    arr[0] = eval('(' + this.response + ')');\n"

         + "  } catch (error) {;\n"

         + "    arr[0] = this.response;\n"

         + "  }\n"

         + "  callback.run__V();\n"

         + "};\n"

         + "request.onerror = function (e) {\n"

         + "  arr[0] = e; onError.run__V();\n"

         + "}\n"

         + "if (data) request.send(data);"

         + "else request.send();"

     )

     static void loadJSON(

         String url, Object[] jsonResult, Runnable whenDone, Runnable whenErr, String method, String data

     ) {

     }

     @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"

     )

     static void loadJSONP(String url, String jsonp) {

     }

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

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

             values[i] = getProperty(jsonObject, props[i]);

         }

     }

 }