/*

 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.

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

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

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

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.nashorn.tools.jjs;

import java.util.Collections;

import java.util.HashSet;

import java.util.Set;

import java.util.function.Consumer;

import java.util.ServiceLoader;

import jdk.nashorn.api.scripting.AbstractJSObject;

import jdk.internal.editor.spi.BuildInEditorProvider;

import jdk.nashorn.internal.runtime.JSType;

import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;

/*

 * "edit" top level script function which shows an external Window

 * for editing and evaluating scripts from it.

 */

final class EditObject extends AbstractJSObject {

    private static final Set<String> props;

    static {

        final HashSet<String> s = new HashSet<>();

        s.add("editor");

        props = Collections.unmodifiableSet(s);

    }

    private final Console console;

    private final Consumer<String> errorHandler;

    private final Consumer<String> evaluator;

    private String editor;

    EditObject(final Console console, final Consumer<String> errorHandler,

            final Consumer<String> evaluator) {

        this.console = console;

        this.errorHandler = errorHandler;

        this.evaluator = evaluator;

    }

    @Override

    public Object getDefaultValue(final Class<?> hint) {

        if (hint == String.class) {

            return toString();

        }

        return UNDEFINED;

    }

    @Override

    public String toString() {

        return "function edit() { [native code] }";

    }

    @Override

    public Set<String> keySet() {

        return props;

    }

    @Override

    public Object getMember(final String name) {

        if (name.equals("editor")) {

            return editor;

        }

        return UNDEFINED;

    }

    @Override

    public void setMember(final String name, final Object value) {

        if (name.equals("editor")) {

            this.editor = value != null && value != UNDEFINED? JSType.toString(value) : "";

        }

    }

    // called whenever user 'saves' script in editor

    class SaveHandler implements Consumer<String> {

         private String lastStr; // last seen code

         SaveHandler(final String str) {

             this.lastStr = str;

         }

         @Override

         public void accept(final String str) {

             // ignore repeated save of the same code!

             if (! str.equals(lastStr)) {

                 this.lastStr = str;

                 // evaluate the new code

                 evaluator.accept(str);

             }

         }

    }

    @Override

    public Object call(final Object thiz, final Object... args) {

        final String initText = args.length > 0? JSType.toString(args[0]) : "";

        final SaveHandler saveHandler = new SaveHandler(initText);

        if (editor != null && !editor.isEmpty()) {

            ExternalEditor.edit(editor, errorHandler, initText, saveHandler, console);

        } else {

            try {

                ServiceLoader<BuildInEditorProvider> sl

                        = ServiceLoader.load(BuildInEditorProvider.class);

                //find the highest ranking provider

                BuildInEditorProvider provider = null;

                for (BuildInEditorProvider p : sl){

                    if (provider == null || p.rank() > provider.rank()) {

                        provider = p;

                    }

                }

                if (provider != null) {

                    provider.edit(null, initText, saveHandler, errorHandler);

                } else {

                    errorHandler.accept(Main.getMessage("jjs.err.no.builtin.editor"));

                }

            } catch (RuntimeException ex) {

                errorHandler.accept(Main.getMessage("jjs.err.cant.launch.editor"));

            }

        }

        return UNDEFINED;

    }

    @Override

    public boolean isFunction() {

        return true;

    }

}