/**

 * 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 netscape.javascript.JSObject;

import org.apidesign.bck2brwsr.core.JavaScriptBody;

/**

 *

 * @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;

        }

    }

    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 = { "url", "arr", "callback" }, body = ""

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

        + "request.open('GET', 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"

        + "    throw 'Cannot parse' + error + ':' + this.response;\n"

        + "  };\n"

        + "  callback.run__V();\n"

        + "};"

        + "request.send();"

    )

    private static void loadJSON(

        String url, Object[] jsonResult, Runnable whenDone

    ) {

    }

    public static void loadJSON(

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

    ) {

        if (jsonp == null) {

            loadJSON(url, jsonResult, whenDone);

        } else {

            loadJSONP(url, jsonp);

        }

    }

    @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) {

    }

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

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

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

        }

    }

}