/*
 * Copyright 2010 JBoss Inc
 *
 * 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.ide.common.client.modeldriven.brl;

/**
 * Represents first order logic like Or, Not, Exists.
 */
public class CompositeFactPattern
    implements
    IPattern {
    public static final String COMPOSITE_TYPE_NOT    = "not";
    public static final String COMPOSITE_TYPE_EXISTS = "exists";
    public static final String COMPOSITE_TYPE_OR     = "or";

    /**
     * this will one of: [Not, Exist, Or]
     */
    public String              type;

    /**
     * The patterns.
     */
    private IFactPattern[]     patterns;

    /**
     * This type should be from the contants in this class of course.
     */
    public CompositeFactPattern(final String type) {
        this.type = type;
    }

    public CompositeFactPattern() {
    }

    public void clearFactPatterns() {
        this.patterns = new FactPattern[0];
    }

    public void addFactPatterns(IFactPattern[] patterns) {
        for ( int i = 0; i < patterns.length; i++ ) {
            IFactPattern iFactPattern = patterns[i];
            this.addFactPattern( iFactPattern );
        }
    }

    public void addFactPattern(final IFactPattern pat) {
        if ( this.patterns == null ) {
            this.patterns = new FactPattern[0];
        }

        final IFactPattern[] list = this.patterns;
        final IFactPattern[] newList = new IFactPattern[list.length + 1];
        System.arraycopy( list,
                          0,
                          newList,
                          0,
                          list.length );
        newList[list.length] = pat;

        this.patterns = newList;
    }

    public IFactPattern[] getPatterns() {
        return patterns;
    }

    /**
     * Remove a FactPattern at the provided index. If index is less than zero or
     * greater than or equal to the number of patterns the effect of this method
     * is "no operation".
     * 
     * @param index
     * @return true if the deletion was successful, i.e. within range
     */
    public boolean removeFactPattern(int index) {
        final int newSize = ((index >= 0 && index < this.patterns.length) ? this.patterns.length - 1 : this.patterns.length);
        final IFactPattern[] newList = new IFactPattern[newSize];
        boolean deleted = false;
        int newIdx = 0;
        for ( int i = 0; i < this.patterns.length; i++ ) {
            if ( i != index ) {
                newList[newIdx] = this.patterns[i];
                newIdx++;
            } else {
                deleted = true;
            }
        }
        this.patterns = newList;
        return deleted;
    }

}
