/*
 * $Id$
 *
 * License Agreement.
 *
 * Rich Faces - Natural Ajax for Java Server Faces (JSF)
 *
 * Copyright (C) 2007 Exadel, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */
package org.richfaces.cdk.generate.freemarker;

import java.util.List;

import org.richfaces.cdk.util.Strings;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;

import freemarker.template.SimpleScalar;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateHashModel;
import freemarker.template.TemplateMethodModel;
import freemarker.template.TemplateMethodModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

/**
 * <p class="changed_added_4_0">
 * This class implements different utility functions used by generator.
 * </p>
 *
 * @author asmirnov@exadel.com
 *
 */
public class FreeMakerUtils implements TemplateHashModel {
    private static final ImmutableSet<String> KEYWORDS = ImmutableSet.of("abstract", "continue", "for", "new", "switch",
            "assert", "default", "goto", "package", "synchronized", "boolean", "do", "if", "private", "this", "break",
            "double", "implements", "protected", "throw", "byte", "else", "import", "public", "throws", "case", "enum",
            "instanceof", "return", "transient", "catch", "extends", "int", "short", "try", "char", "final", "interface",
            "static", "void", "class", "finally", "long", "strictfp", "volatile", "const", "float", "native", "super", "while");
    private static final ImmutableMap<String, ? extends TemplateMethodModel> FUNCTIONS = ImmutableMap
            .<String, TemplateMethodModel>builder().put("version", new TemplateMethodModelEx() {
                @SuppressWarnings("unchecked")
                @Override
                public Object exec(List arguments) throws TemplateModelException {
                    return new SimpleScalar("4.0.0");
                }
            }).put("capitaliyze", new TemplateMethodModel() {
                @SuppressWarnings("unchecked")
                @Override
                public Object exec(List arguments) throws TemplateModelException {
                    if (arguments.size() == 1) {
                        return new SimpleScalar(Strings.firstToUpperCase(arguments.get(0).toString()));
                    } else {
                        return null;
                    }
                }
            }).put("isKeyword", new TemplateMethodModel() {
                @SuppressWarnings("unchecked")
                @Override
                public Object exec(List arguments) throws TemplateModelException {
                    if (arguments.size() == 1) {
                        return KEYWORDS.contains(arguments.get(0).toString()) ? TemplateBooleanModel.TRUE
                                : TemplateBooleanModel.FALSE;
                    } else {
                        return null;
                    }
                }
            }).build();

    /*
     * (non-Javadoc)
     *
     * @see freemarker.template.TemplateHashModel#get(java.lang.String)
     */
    @Override
    public TemplateModel get(String key) throws TemplateModelException {
        return FUNCTIONS.get(key);
    }

    /*
     * (non-Javadoc)
     *
     * @see freemarker.template.TemplateHashModel#isEmpty()
     */
    @Override
    public boolean isEmpty() throws TemplateModelException {
        return false;
    }
}