/*
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jbpm.compiler.xml.compiler.rules;

import org.drools.drl.ast.descr.FunctionImportDescr;
import org.drools.drl.ast.descr.GlobalDescr;
import org.drools.drl.ast.descr.ImportDescr;
import org.drools.drl.ast.descr.PackageDescr;
import org.jbpm.compiler.xml.Handler;
import org.jbpm.compiler.xml.Parser;
import org.jbpm.compiler.xml.core.BaseAbstractHandler;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 *
 * TODO To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
public class PackageHandler extends BaseAbstractHandler
        implements
        Handler {
    public PackageHandler() {
    }

    public Object start(final String uri,
            final String localName,
            final Attributes attrs,
            final Parser parser) throws SAXException {
        parser.startElementBuilder(localName,
                attrs);

        final String ruleSetName = attrs.getValue("name");

        if (ruleSetName == null || ruleSetName.trim().equals("")) {
            throw new SAXParseException("<package> requires a 'name' attribute",
                    parser.getLocator());
        }

        final PackageDescr packageDescr = new PackageDescr(ruleSetName.trim());

        parser.setData(packageDescr);
        return packageDescr;
    }

    public Object end(final String uri,
            final String localName,
            final Parser parser) throws SAXException {
        final PackageDescr packageDescr = (PackageDescr) parser.getData();
        final Element element = parser.endElementBuilder();

        NodeList imports = element.getElementsByTagName("import");

        for (int i = 0, length = imports.getLength(); i < length; i++) {
            final String importEntry = ((Element) imports.item(i)).getAttribute("name");

            if (importEntry == null || importEntry.trim().equals("")) {
                throw new SAXParseException("<import> cannot be blank",
                        parser.getLocator());
            }
            packageDescr.addImport(new ImportDescr(importEntry));
        }

        NodeList importfunctions = element.getElementsByTagName("importfunction");

        for (int i = 0, length = importfunctions.getLength(); i < length; i++) {
            final String importfunctionEntry = ((Element) importfunctions.item(i)).getAttribute("name");

            if (importfunctionEntry == null || importfunctionEntry.trim().equals("")) {
                throw new SAXParseException("<importfunction> cannot be blank",
                        parser.getLocator());
            }

            FunctionImportDescr funcdescr = new FunctionImportDescr();
            funcdescr.setTarget(importfunctionEntry);

            packageDescr.addFunctionImport(funcdescr);
        }

        NodeList globals = element.getElementsByTagName("global");

        for (int i = 0, length = globals.getLength(); i < length; i++) {
            final String identifier = ((Element) globals.item(i)).getAttribute("identifier");

            if (identifier == null || identifier.trim().equals("")) {
                throw new SAXParseException("<global> must have an identifier",
                        parser.getLocator());
            }

            final String type = ((Element) globals.item(i)).getAttribute("type");
            if (type == null || type.trim().equals("")) {
                throw new SAXParseException("<global> must have specify a type",
                        parser.getLocator());
            }
            final GlobalDescr global = new GlobalDescr(identifier,
                    type);
            packageDescr.addGlobal(global);
        }

        return packageDescr;
    }

    public Class generateNodeFor() {
        return PackageDescr.class;
    }
}
