/*
 * $Id: RegexpCondition.java,v 1.1 2008/02/06 10:43:25 linkconsulting Exp $
 *
 *  Copyright (c) 2001-2005 The Open For Business Project - www.ofbiz.org
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a
 *  copy of this software and associated documentation files (the "Software"),
 *  to deal in the Software without restriction, including without limitation
 *  the rights to use, copy, modify, merge, publish, distribute, sublicense,
 *  and/or sell copies of the Software, and to permit persons to whom the
 *  Software is furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included
 *  in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 *  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 *  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 *  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
 *  OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
 *  THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
package org.ofbiz.minilang.method.conditional;

import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.PatternCompiler;
import org.apache.oro.text.regex.PatternMatcher;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;
import org.ofbiz.base.util.Debug;
import org.ofbiz.base.util.GeneralException;
import org.ofbiz.base.util.ObjectType;
import org.ofbiz.base.util.string.FlexibleStringExpander;
import org.ofbiz.minilang.SimpleMethod;
import org.ofbiz.minilang.method.ContextAccessor;
import org.ofbiz.minilang.method.MethodContext;
import org.w3c.dom.Element;

/**
 * Implements compare to a constant condition.
 *
 * @author     <a href="mailto:jonesde@ofbiz.org">David E. Jones</a>
 * @version    $Rev: 6237 $
 * @since      2.1
 */
public class RegexpCondition implements Conditional {
    
    public static final String module = RegexpCondition.class.getName();
    
    SimpleMethod simpleMethod;
    
    static PatternMatcher matcher = new Perl5Matcher();
    static PatternCompiler compiler = new Perl5Compiler();

    List subOps = new LinkedList();
    List elseSubOps = null;

    ContextAccessor mapAcsr;
    ContextAccessor fieldAcsr;

    FlexibleStringExpander exprExdr;
    
    public RegexpCondition(Element element, SimpleMethod simpleMethod) {
        this.simpleMethod = simpleMethod;
        
        this.mapAcsr = new ContextAccessor(element.getAttribute("map-name"));
        this.fieldAcsr = new ContextAccessor(element.getAttribute("field-name"));

        this.exprExdr = new FlexibleStringExpander(element.getAttribute("expr"));
    }

    public boolean checkCondition(MethodContext methodContext) {
        String fieldString = getFieldString(methodContext);

        Pattern pattern = null;
        try {
            pattern = compiler.compile(methodContext.expandString(this.exprExdr));
        } catch (MalformedPatternException e) {
            Debug.logError(e, "Regular Expression [" + this.exprExdr + "] is mal-formed: " + e.toString(), module);
        }

        if (matcher.matches(fieldString, pattern)) {
            //Debug.logInfo("The string [" + fieldString + "] matched the pattern expr [" + pattern.getPattern() + "]", module);
            return true;
        } else {
            //Debug.logInfo("The string [" + fieldString + "] did NOT match the pattern expr [" + pattern.getPattern() + "]", module);
            return false;
        }
    }
    
    protected String getFieldString(MethodContext methodContext) {
        String fieldString = null;
        Object fieldVal = null;

        if (!mapAcsr.isEmpty()) {
            Map fromMap = (Map) mapAcsr.get(methodContext);
            if (fromMap == null) {
                if (Debug.infoOn()) Debug.logInfo("Map not found with name " + mapAcsr + ", using empty string for comparison", module);
            } else {
                fieldVal = fieldAcsr.get(fromMap, methodContext);
            }
        } else {
            // no map name, try the env
            fieldVal = fieldAcsr.get(methodContext);
        }

        if (fieldVal != null) {
            try {
                fieldString = (String) ObjectType.simpleTypeConvert(fieldVal, "String", null, null);
            } catch (GeneralException e) {
                Debug.logError(e, "Could not convert object to String, using empty String", module);
            }
        }
        // always use an empty string by default
        if (fieldString == null) fieldString = "";
        
        return fieldString;
    }

    public void prettyPrint(StringBuffer messageBuffer, MethodContext methodContext) {
        messageBuffer.append("regexp[");
        messageBuffer.append("[");
        if (!this.mapAcsr.isEmpty()) {
            messageBuffer.append(this.mapAcsr);
            messageBuffer.append(".");
        }
        messageBuffer.append(this.fieldAcsr);
        messageBuffer.append("=");
        messageBuffer.append(getFieldString(methodContext));
        messageBuffer.append("] matches ");
        messageBuffer.append(methodContext.expandString(this.exprExdr));
        messageBuffer.append("]");
    }
}
