/**

  * 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.kofx;

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.InputStreamReader;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import net.java.html.js.JavaScriptBody;

 import net.java.html.json.Model;

 import netscape.javascript.JSObject;

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

 import org.apidesign.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 <jtulach@netbeans.org>

  */

 public final class Knockout {

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

     /** used by tests */

     static Knockout next;

     private final Object model;

     Knockout(Object model) {

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

     }

     public Object koData() {

         return model;

     }

     static Object toArray(Object[] arr) {

         return InvokeJS.KObject.call("array", arr);

     }

     private static int cnt;

     public static <M> Knockout createBinding(Object model) {

         Object bindings = InvokeJS.create(model, ++cnt);

         return new Knockout(bindings);

     }

     public void valueHasMutated(String prop) {

         valueHasMutated((JSObject) model, prop);

     }

     public static void valueHasMutated(JSObject model, String prop) {

         LOG.log(Level.FINE, "property mutated: {0}", prop);

         try {

             Object koProp = model.getMember(prop);

             if (koProp instanceof JSObject) {

                 ((JSObject)koProp).call("valueHasMutated");

             }

         } catch (Throwable t) {

             LOG.log(Level.WARNING, "valueHasMutated failed for " + model + " prop: " + prop, t);

         }

     }

     static void bind(

         Object bindings, Object model, PropertyBinding pb, boolean primitive, boolean array

     ) {

         final String prop = pb.getPropertyName();

         try {

             InvokeJS.bind(bindings, pb, prop, "getValue", pb.isReadOnly() ? null : "setValue", primitive, array);

             ((JSObject)bindings).setMember("ko-fx.model", model);

             LOG.log(Level.FINE, "binding defined for {0}: {1}", new Object[]{prop, ((JSObject)bindings).getMember(prop)});

         } catch (Throwable ex) {

             LOG.log(Level.WARNING, "binding failed for {0} on {1}", new Object[]{prop, bindings});

         }

     }

     static void expose(Object bindings, FunctionBinding f) {

         final String prop = f.getFunctionName();

         try {

             InvokeJS.expose(bindings, f, prop, "call");

         } catch (Throwable ex) {

             LOG.log(Level.SEVERE, "Cannot define binding for " + prop + " in model " + f, ex);

         }

     }

     static void applyBindings(Object bindings) {

         InvokeJS.applyBindings(bindings);

     }

     private static final class InvokeJS {

         static final JSObject KObject;

         static {

             final InputStream koScript = Knockout.class.getResourceAsStream("knockout-2.2.1.js");

             assert koScript != null : "Can't load knockout.js";

             BufferedReader r = new BufferedReader(new InputStreamReader(koScript));

             StringBuilder sb = new StringBuilder();

             for (;;) {

                 try {

                     String l = r.readLine();

                     if (l == null) {

                         break;

                     }

                     sb.append(l).append('\n');

                 } catch (IOException ex) {

                     throw new IllegalStateException(ex);

                 }

             }

             exec(sb.toString());

             Object ko = exec("ko");

             assert ko != null : "Knockout library successfully defined 'ko'";

             Console.register();

             KObject = (JSObject) kObj();

         }

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

         private static native Object exec(String s);

         @JavaScriptBody(args = {}, body =

                   "  var k = {};"

                 + "  k.array= function() {"

                 + "    return Array.prototype.slice.call(arguments);"

                 + "  };"

                 + "  return k;"

         )

         private static native Object kObj();

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

                   "    var ret = {};"

                 + "    ret.toString = function() { return 'KObject' + cnt + ' value: ' + value + ' props: ' + Object.keys(this); };"

                 + "    return ret;"

         )

         static native Object create(Object value, int cnt);

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

                 "    bindings[prop] = function(data, ev) {"

               //            + "         console.log(\"  callback on prop: \" + prop);"

               + "      model[sig](data, ev);"

               + "    };"

         )

         static native Object expose(Object bindings, Object model, String prop, String sig);

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

                   "    var bnd = {"

                 + "      read: function() {"

                 + "      try {"

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

         //        + "      console.log(\" getter value \" + v + \" for property \" + prop);"

         //        + "      try { v = v.koData(); } catch (ignore) {"

         //        + "        console.log(\"Cannot convert to koData: \" + ignore);"

         //        + "      };"

         //        + "      console.log(\" getter ret value \" + v);"

         //        + "      for (var pn in v) {"

         //        + "         console.log(\"  prop: \" + pn + \" + in + \" + v + \" = \" + v[pn]);"

         //        + "         if (typeof v[pn] == \"function\") console.log(\"  its function value:\" + v[pn]());"

         //        + "      }"

         //        + "      console.log(\" all props printed for \" + (typeof v));"

                 + "        return v;"

                 + "      } catch (e) {"

                 + "        alert(\"Cannot call \" + getter + \" on \" + model + \" error: \" + e);"

                 + "      }"

                 + "    },"

                 + "    owner: bindings"

         //        + "  ,deferEvaluation: true"

                 + "    };"

                 + "    if (setter != null) {"

                 + "      bnd.write = function(val) {"

                 + "        model[setter](primitive ? new Number(val) : val);"

                 + "      };"

                 + "    };"

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

         )

         static native void bind(Object binding, Object model, String prop, String getter, String setter, boolean primitive, boolean array);

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

         private static native void applyBindings(Object bindings);

     }

 }