/**

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 *

 * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.

 *

 * Oracle and Java are registered trademarks of Oracle and/or its affiliates.

 * Other names may be trademarks of their respective owners.

 *

 * The contents of this file are subject to the terms of either the GNU

 * General Public License Version 2 only ("GPL") or the Common

 * Development and Distribution License("CDDL") (collectively, the

 * "License"). You may not use this file except in compliance with the

 * License. You can obtain a copy of the License at

 * http://www.netbeans.org/cddl-gplv2.html

 * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the

 * specific language governing permissions and limitations under the

 * License.  When distributing the software, include this License Header

 * Notice in each file and include the License file at

 * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the GPL Version 2 section of the License file that

 * accompanied this code. If applicable, add the following below the

 * License Header, with the fields enclosed by brackets [] replaced by

 * your own identifying information:

 * "Portions Copyrighted [year] [name of copyright owner]"

 *

 * Contributor(s):

 *

 * The Original Software is NetBeans. The Initial Developer of the Original

 * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.

 *

 * If you wish your version of this file to be governed by only the CDDL

 * or only the GPL Version 2, indicate your decision by adding

 * "[Contributor] elects to include this software in this distribution

 * under the [CDDL or GPL Version 2] license." If you do not indicate a

 * single choice of license, a recipient has the option to distribute

 * your version of this file under either the CDDL, the GPL Version 2 or

 * to extend the choice of license to its licensees as provided above.

 * However, if you add GPL Version 2 code and therefore, elected the GPL

 * Version 2 license, then the option applies only if the new code is

 * made subject to such option by the copyright holder.

 */

package org.netbeans.html.ko4j;

import java.lang.ref.ReferenceQueue;

import java.lang.ref.WeakReference;

import net.java.html.js.JavaScriptBody;

import net.java.html.js.JavaScriptResource;

import net.java.html.json.Model;

import org.netbeans.html.json.spi.FunctionBinding;

import org.netbeans.html.json.spi.PropertyBinding;

/** This is an implementation package - just

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

 * to access the functionality.

 * <p>

 * Provides binding between {@link Model models} and knockout.js running

 * inside a JavaFX WebView. 

 *

 * @author Jaroslav Tulach

 */

@JavaScriptResource("knockout-3.2.0.debug.js")

final class Knockout extends WeakReference<Object> {

    private static final ReferenceQueue<Object> QUEUE = new ReferenceQueue();

    private PropertyBinding[] props;

    private FunctionBinding[] funcs;

    private Object js;

    private Object strong;

    public Knockout(Object model, Object js, PropertyBinding[] props, FunctionBinding[] funcs) {

        super(model, QUEUE);

        this.js = js;

        this.props = new PropertyBinding[props.length];

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

            this.props[i] = props[i].weak();

        }

        this.funcs = new FunctionBinding[funcs.length];

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

            this.funcs[i] = funcs[i].weak();

        }

    }

    static void cleanUp() {

        for (;;) {

            Knockout ko = (Knockout)QUEUE.poll();

            if (ko == null) {

                return;

            }

            clean(ko.js);

            ko.js = null;

            ko.props = null;

            ko.funcs = null;

        }

    }

    final void hold() {

        strong = get();

    }

    final Object getValue(int index) {

        return props[index].getValue();

    }

    final void setValue(int index, Object v) {

        if (v instanceof Knockout) {

            v = ((Knockout)v).get();

        }

        props[index].setValue(v);

    }

    final void call(int index, Object data, Object ev) {

        funcs[index].call(data, ev);

    }

    @JavaScriptBody(args = { "model", "prop", "oldValue", "newValue" }, 

        wait4js = false,

        body =

          "if (model) {\n"

        + "  var koProp = model[prop];\n"

        + "  if (koProp && koProp['valueHasMutated']) {\n"

        + "    if ((oldValue !== null || newValue !== null)) {\n"

        + "      koProp['valueHasMutated'](newValue);\n"

        + "    } else if (koProp['valueHasMutated']) {\n"

        + "      koProp['valueHasMutated']();\n"

        + "    }\n"

        + "  }\n"

        + "}\n"

    )

    public native static void valueHasMutated(

        Object model, String prop, Object oldValue, Object newValue

    );

    @JavaScriptBody(args = { "bindings" }, body = 

        "ko['cleanNode'](window['document']['body']);\n" +

        "ko['applyBindings'](bindings);\n" +

        "return bindings['ko4j'];\n"

    )

    native static Object applyBindings(Object bindings);

    @JavaScriptBody(args = { "cnt" }, body = 

        "var arr = new Array(cnt);\n" +

        "for (var i = 0; i < cnt; i++) arr[i] = new Object();\n" +

        "return arr;\n"

    )

    native static Object[] allocJS(int cnt);

    @JavaScriptBody(

        javacall = true,

        wait4js = false,

        args = { "thiz", "ret", "propNames", "propReadOnly", "propValues", "funcNames" },

        body = 

          "Object.defineProperty(ret, 'ko4j', { value : thiz });\n"

        + "function koComputed(index, name, readOnly, value) {\n"

        + "  var trigger = ko['observable']()['extend']({'notify':'always'});"

        + "  function realGetter() {\n"

        + "    var self = ret['ko4j'];\n"

        + "    try {\n"

        + "      var v = self ? self.@org.netbeans.html.ko4j.Knockout::getValue(I)(index) : null;\n"

        + "      return v;\n"

        + "    } catch (e) {\n"

        + "      alert(\"Cannot call getValue on \" + self + \" prop: \" + name + \" error: \" + e);\n"

        + "    }\n"

        + "  }\n"

        + "  var activeGetter = function() { return value; };\n"

        + "  var bnd = {\n"

        + "    'read': function() {\n"

        + "      trigger();\n"

        + "      var r = activeGetter();\n"

        + "      activeGetter = realGetter;\n"

        + "      if (r) try { var br = r.valueOf(); } catch (err) {}\n"

        + "      return br === undefined ? r: br;\n"

        + "    },\n"

        + "    'owner': ret\n"

        + "  };\n"

        + "  if (!readOnly) {\n"

        + "    bnd['write'] = function(val) {\n"

        + "      var self = ret['ko4j'];\n"

        + "      if (!self) return;\n"

        + "      var model = val['ko4j'];\n"

        + "      var s = ret['ko4j'];\n"

        + "      s.@org.netbeans.html.ko4j.Knockout::setValue(ILjava/lang/Object;)(index, model ? model : val);\n"

        + "    };\n"

        + "  };\n"

        + "  var cmpt = ko['computed'](bnd);\n"

        + "  cmpt['valueHasMutated'] = function(val) {\n"

        + "    if (arguments.length === 1) activeGetter = function() { return val; };\n"

        + "    trigger['valueHasMutated']();\n"

        + "  };\n"

        + "  ret[name] = cmpt;\n"

        + "}\n"

        + "for (var i = 0; i < propNames.length; i++) {\n"

        + "  koComputed(i, propNames[i], propReadOnly[i], propValues[i]);\n"

        + "}\n"

        + "function koExpose(index, name) {\n"

        + "  ret[name] = function(data, ev) {\n"

        + "    var self = ret['ko4j'];\n"

        + "    if (!self) return;\n"

        + "    self.@org.netbeans.html.ko4j.Knockout::call(ILjava/lang/Object;Ljava/lang/Object;)(index, data, ev);\n"

        + "  };\n"

        + "}\n"

        + "for (var i = 0; i < funcNames.length; i++) {\n"

        + "  koExpose(i, funcNames[i]);\n"

        + "}\n"

        )

    static native void wrapModel(

        Knockout self,

        Object ret, 

        String[] propNames, boolean[] propReadOnly, Object propValues,

        String[] funcNames

    );

    @JavaScriptBody(args = { "js" }, wait4js = false, body = 

        "delete js['ko4j'];\n" +

        "for (var p in js) {\n" +

        "  delete js[p];\n" +

        "};\n" +

        "\n"

    )

    private static native void clean(Object js);

    @JavaScriptBody(args = { "o" }, body = "return o['ko4j'] ? o['ko4j'] : o;")

    private static native Object toModelImpl(Object wrapper);

    static Object toModel(Object wrapper) {

        Object o = toModelImpl(wrapper);

        if (o instanceof Knockout) {

            return ((Knockout)o).get();

        } else {

            return o;

        }

    }

}