/**

 * 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.html.ko2brwsr;

import java.lang.reflect.Method;

import java.util.List;

import org.apidesign.bck2brwsr.core.ExtraJavaScript;

import org.apidesign.bck2brwsr.core.JavaScriptBody;

/** Provides binding between models and bck2brwsr VM.

 *

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

 */

@ExtraJavaScript(resource = "/org/apidesign/bck2brwsr/htmlpage/knockout-2.2.1.js")

final class Knockout {

    /** used by tests */

    static Knockout next;

    private final Object model;

    Knockout(Object model) {

        this.model = model == null ? this : model;

    }

    public static <M> Knockout applyBindings(

        Object model, String[] propsGettersAndSetters,

        String[] methodsAndSignatures

    ) {

        applyImpl(propsGettersAndSetters, model.getClass(), model, model, methodsAndSignatures);

        return new Knockout(model);

    }

    public static <M> Knockout applyBindings(

        Class<M> modelClass, M model, String[] propsGettersAndSetters,

        String[] methodsAndSignatures

    ) {

        Knockout bindings = next;

        next = null;

        if (bindings == null) {

            bindings = new Knockout(null);

        }

        applyImpl(propsGettersAndSetters, modelClass, bindings, model, methodsAndSignatures);

        applyBindings(bindings);

        return bindings;

    }

    public void valueHasMutated(String prop) {

        valueHasMutated(model, prop);

    }

    @JavaScriptBody(args = { "self", "prop" }, body =

        "var p = self[prop]; if (p) p.valueHasMutated();"

    )

    public static void valueHasMutated(Object self, String prop) {

    }

    @JavaScriptBody(args = { "id", "ev" }, body = "ko.utils.triggerEvent(window.document.getElementById(id), ev.substring(2));")

    public static void triggerEvent(String id, String ev) {

    }

    @JavaScriptBody(args = { "bindings", "model", "prop", "getter", "setter", "primitive", "array" }, body =

          "var bnd = {\n"

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

        + "    var v = model[getter]();\n"

        + "    if (array) v = v.koArray(); else if (v !== null) v = v.valueOf();\n"

        + "    return v;\n"

        + "  },\n"

        + "  'owner': bindings\n"

        + "};\n"

        + "if (setter != null) {\n"

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

        + "    var v = val === null ? null : val.valueOf();"

        + "    model[setter](v);\n"

        + "  };\n"

        + "}\n"

        + "bindings[prop] = ko['computed'](bnd);"

    )

    static void bind(

        Object bindings, Object model, String prop, String getter, String setter, boolean primitive, boolean array

    ) {

    }

    @JavaScriptBody(args = { "bindings", "model", "prop", "sig" }, body = 

        "bindings[prop] = function(data, ev) { model[sig](data, ev); };"

    )

    static void expose(

        Object bindings, Object model, String prop, String sig

    ) {

    }

    @JavaScriptBody(args = { "bindings" }, body = "ko.applyBindings(bindings);")

    static void applyBindings(Object bindings) {}

    private static void applyImpl(

        String[] propsGettersAndSetters,

        Class<?> modelClass,

        Object bindings,

        Object model,

        String[] methodsAndSignatures

    ) throws IllegalStateException, SecurityException {

        for (int i = 0; i < propsGettersAndSetters.length; i += 4) {

            try {

                Method getter = modelClass.getMethod(propsGettersAndSetters[i + 3]);

                bind(bindings, model, propsGettersAndSetters[i],

                    propsGettersAndSetters[i + 1],

                    propsGettersAndSetters[i + 2],

                    getter.getReturnType().isPrimitive(),

                    List.class.isAssignableFrom(getter.getReturnType()));

            } catch (NoSuchMethodException ex) {

                throw new IllegalStateException(ex.getMessage());

            }

        }

        for (int i = 0; i < methodsAndSignatures.length; i += 2) {

            expose(

                bindings, model, methodsAndSignatures[i], methodsAndSignatures[i + 1]);

        }

    }

}