/*
 * 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.drools.eclipse.core;

import org.eclipse.core.resources.IFile;

/**
 * This represents a drools model element.  It is linked to its direct
 * parents and its children. If relevant, Drools model elements refer
 * to the file they are defined in and the offset and length of that
 * element in the file. 
 */
public abstract class DroolsElement {

    public static final int RULESET = 0;
    public static final int PACKAGE = 1;
    public static final int RULE = 2;
    public static final int QUERY = 3;
    public static final int FUNCTION = 4;
    public static final int TEMPLATE = 5;
    public static final int EXPANDER = 6;
    public static final int GLOBAL = 7;
    public static final int IMPORT = 8;
    public static final int RULE_ATTRIBUTE = 9;
    public static final int PROCESS = 10;
    
    public static final int DEFAULT_RULE_GROUP = 11;
    public static final int ACTIVATION_GROUP = 12;
    public static final int AGENDA_GROUP = 13;
    public static final int RULEFLOW_GROUP = 14;

    protected static final DroolsElement[] NO_ELEMENTS = new DroolsElement[0];

    private DroolsElement parent;
    private IFile file;
    private int offset;
    private int length;

    protected DroolsElement(DroolsElement parent) {
        this.parent = parent;
    }

    public abstract int getType();

    public DroolsElement getParent() {
        return parent;
    }

    public abstract DroolsElement[] getChildren();

    public IFile getFile() {
        return file;
    }

    public int getOffset() {
        return offset;
    }

    public int getLength() {
        return length;
    }

    // These are helper methods for creating the model and should not
    // be used directly.  Use DroolsModelBuilder instead.

    void setFile(IFile file, int offset, int length) {
        this.file = file;
        this.offset = offset;
        this.length = length;
    }

}