package org.drools.lang;
/*
* Author Jayaram C S
*
* 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.
*/
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.drools.lang.descr.AccumulateDescr;
import org.drools.lang.descr.AndDescr;
import org.drools.lang.descr.AttributeDescr;
import org.drools.lang.descr.CollectDescr;
import org.drools.lang.descr.EvalDescr;
import org.drools.lang.descr.ExistsDescr;
import org.drools.lang.descr.FieldBindingDescr;
import org.drools.lang.descr.FieldConstraintDescr;
import org.drools.lang.descr.ForallDescr;
import org.drools.lang.descr.FromDescr;
import org.drools.lang.descr.FunctionDescr;
import org.drools.lang.descr.FunctionImportDescr;
import org.drools.lang.descr.GlobalDescr;
import org.drools.lang.descr.ImportDescr;
import org.drools.lang.descr.LiteralRestrictionDescr;
import org.drools.lang.descr.NotDescr;
import org.drools.lang.descr.OrDescr;
import org.drools.lang.descr.PackageDescr;
import org.drools.lang.descr.PackageDescrDumper;
import org.drools.lang.descr.PatternDescr;
import org.drools.lang.descr.PredicateDescr;
import org.drools.lang.descr.QualifiedIdentifierRestrictionDescr;
import org.drools.lang.descr.QueryDescr;
import org.drools.lang.descr.RestrictionConnectiveDescr;
import org.drools.lang.descr.ReturnValueRestrictionDescr;
import org.drools.lang.descr.RuleDescr;
import org.drools.lang.descr.VariableRestrictionDescr;
import org.drools.util.ReflectiveVisitor;
/**
*
* @author <a href="mailto:jayaramcs@gmail.com">Author Jayaram C S</a>
*
*/
public class DrlDumper extends ReflectiveVisitor
implements
PackageDescrDumper {
private StringBuffer drlDump;
private static final String eol = System.getProperty( "line.separator" );
private String template;
private boolean needsBracket = false;
public synchronized String dump(final PackageDescr packageDescr) {
this.drlDump = new StringBuffer();
visitPackageDescr( packageDescr );
return this.drlDump.toString();
}
public String getTemplate() {
return this.template;
}
public void visitAndDescr(final AndDescr descr) {
this.template = new String();
if ( !descr.getDescrs().isEmpty() ) {
this.template = processDescrList( descr.getDescrs() );
} else {
this.template = "";
}
}
private static Set needsQuotes = new HashSet();
static {
needsQuotes.add( "agenda-group" );
needsQuotes.add( "activation-group" );
needsQuotes.add( "ruleflow-group" );
needsQuotes.add( "date-effective" );
needsQuotes.add( "date-expires" );
needsQuotes.add( "dialect" );
}
public void visitAttributeDescr(final AttributeDescr attributeDescr) {
this.template = new String();
final String name = attributeDescr.getName();
String value = null;
if ( needsQuotes.contains( name) ) {
// These attributes may need quotes around them, if they have spaces, so add anyway
value = "\"" + attributeDescr.getValue() + "\"";
} else {
value = attributeDescr.getValue();
}
this.template = "\t " + name + " " + value + DrlDumper.eol;
}
public void visitFieldConstraintDescr(final FieldConstraintDescr descr) {
if ( !descr.getRestrictions().isEmpty() ) {
this.template = descr.getFieldName() + " " + processFieldConstraint( descr.getRestriction(),
false );
}
}
public void visitVariableRestrictionDescr(final VariableRestrictionDescr descr) {
this.template = new String();
this.template = descr.getEvaluator() + " " + descr.getIdentifier();
}
public void visitPatternDescr(final PatternDescr descr) {
StringBuffer buf = new StringBuffer();
buf.append( "\t\t" );
if ( descr.getIdentifier() != null ) {
buf.append( descr.getIdentifier() );
buf.append( " : " );
}
buf.append( descr.getObjectType() );
buf.append( "( " );
if ( !descr.getConstraint().getDescrs().isEmpty() ) {
buf.append( processColoumnConstraintList( descr.getConstraint().getDescrs() ) );
}
buf.append( " )" );
if( descr.getSource() != null ) {
buf.append( " from " );
this.template = buf.toString();
visit( descr.getSource() );
buf.append( this.template );
}
this.template = buf.toString();
}
public void visitEvalDescr(final EvalDescr descr) {
this.template = new String();
this.template = "\t\teval ( " + descr.getContent() + " )" + DrlDumper.eol;
}
public void visitExistsDescr(final ExistsDescr descr) {
this.template = new String();
if ( !descr.getDescrs().isEmpty() ) {
this.template = "\t\texists " + processDescrList( descr.getDescrs() ) + ";";
} else {
this.template = "";
}
}
public void visitCollectDescr(final CollectDescr descr) {
String tmpstr = new String();
tmpstr += " collect (";
visitPatternDescr( descr.getInputPattern() );
tmpstr += this.template.substring( 2 );
this.template = tmpstr + ");";
}
public void visitAccumulateDescr(final AccumulateDescr descr) {
String tmpstr = new String();
tmpstr += " accumulate (";
if ( descr.isSinglePattern() ) {
visitPatternDescr( descr.getInputPattern() );
} else {
visit(descr.getInput());
}
tmpstr += this.template.substring( 2 );
if ( descr.isExternalFunction() ) {
tmpstr += "," + descr.getFunctionIdentifier() + "(" + descr.getExpression() + ")";
} else {
tmpstr += ", init(" + descr.getInitCode() + "), ";
tmpstr += "action(" + descr.getActionCode() + "), ";
if( descr.getReverseCode() != null ) {
tmpstr += " reverse(" + descr.getReverseCode() +"), ";
}
tmpstr += "result(" + descr.getResultCode() + ")";
}
this.template = tmpstr + ");";
}
public void visitFromDescr(final FromDescr descr) {
this.template = descr.getDataSource().toString();
}
public void visitForallDescr(final ForallDescr descr) {
String localstr = new String();
localstr += "\t\tforall ( ";
localstr += DrlDumper.eol;
for ( final Iterator ite = descr.getDescrs().iterator(); ite.hasNext(); ) {
Object obj = ite.next();
visit( obj );
localstr += this.template + DrlDumper.eol;
}
this.template = localstr;
this.template += "\t\t)";
this.template += DrlDumper.eol;
}
public void visitFieldBindingDescr(final FieldBindingDescr descr) {
this.template = new String();
this.template = descr.getIdentifier() + " : " + descr.getFieldName();
}
public void visitFunctionDescr(final FunctionDescr functionDescr) {
this.template = new String();
final String parameterTemplate = processParameters( functionDescr.getParameterNames(),
functionDescr.getParameterTypes() );
this.template = "function " + functionDescr.getReturnType() + " " + functionDescr.getName() + "(" + parameterTemplate + "){" +
functionDescr.getText() + DrlDumper.eol + "}" + DrlDumper.eol;
}
public void visitLiteralRestrictionDescr(final LiteralRestrictionDescr descr) {
this.template = "";
String text = descr.getText();
if ( text == null || descr.getType() == LiteralRestrictionDescr.TYPE_NULL ) {
text = "null";
} else if( descr.getType() == LiteralRestrictionDescr.TYPE_NUMBER ) {
try {
Integer.parseInt( text );
} catch ( final NumberFormatException e ) {
text = "\"" + text + "\"";
}
} else if( descr.getType() == LiteralRestrictionDescr.TYPE_STRING ) {
text = "\"" + text + "\"";
}
this.template = descr.getEvaluator() + " " + text;
}
public void visitQualifiedIdentifierRestrictionDescr(final QualifiedIdentifierRestrictionDescr descr) {
this.template = descr.getEvaluator() + " " + descr.getText();
}
public void visitRestrictionConnectiveDescr(final RestrictionConnectiveDescr descr) {
String tmp = this.processFieldConstraint( descr,
true );
this.template = tmp;
}
public void visitNotDescr(final NotDescr descr) {
this.template = new String();
if ( !descr.getDescrs().isEmpty() ) {
this.template = "\t not ( " + processDescrList( descr.getDescrs() ) +")";
} else {
this.template = "";
}
}
public void visitOrDescr(final OrDescr descr) {
this.template = new String();
if ( !descr.getDescrs().isEmpty() ) {
this.template = processOrDescrList( descr.getDescrs() );
} else {
this.template = " ";
}
}
public void visitPackageDescr(final PackageDescr packageDescr) {
final String packageName = packageDescr.getName();
final String xmlString = "package " + packageName + ";" + DrlDumper.eol + DrlDumper.eol;
appendDrlDump( xmlString );
if ( packageDescr.getImports() != null ) {
appendDrlDump( processImportsList( packageDescr.getImports() ) );
}
if ( packageDescr.getGlobals() != null ) {
appendDrlDump( processGlobalsList( packageDescr.getGlobals() ) );
}
if ( packageDescr.getFunctionImports() != null ) {
appendDrlDump( processFunctionImportsList( packageDescr.getFunctionImports() ) );
}
if ( packageDescr.getFunctions() != null ) {
appendDrlDump( processFunctionsList( packageDescr.getFunctions() ) );
}
if ( packageDescr.getRules() != null ) {
appendDrlDump( processRules( packageDescr.getRules() ) );
}
}
public void visitPredicateDescr(final PredicateDescr descr) {
this.template = new String();
this.template = "eval( " + descr.getContent() + " )";
}
public void visitReturnValueRestrictionDescr(final ReturnValueRestrictionDescr descr) {
this.template = new String();
this.template = descr.getEvaluator() + " ( " + descr.getContent() + ")";
}
public void visitQueryDescr(final QueryDescr descr) {
this.template = new String();
this.template = "query \"" + descr.getName() + "\"" + processDescrList( descr.getLhs().getDescrs() ) + "end";
}
private String processRules(final List rules) {
String ruleList = "";
Object ruleobj;
for ( final Iterator iterator = rules.iterator(); iterator.hasNext(); ) {
ruleobj = iterator.next();
if ( ruleobj instanceof QueryDescr ) {
visitQueryDescr((QueryDescr) ruleobj);
ruleList += this.template;
break;
}
final RuleDescr ruleDescr = (RuleDescr) ruleobj;
String rule = "rule \"" + ruleDescr.getName() + "\" " + DrlDumper.eol;
final String attribute = processAttribute( ruleDescr.getAttributes() );
String lhs = "";
if ( !ruleDescr.getLhs().getDescrs().isEmpty() ) {
lhs = "\t when" + DrlDumper.eol + processDescrList( ruleDescr.getLhs().getDescrs() ) + DrlDumper.eol;
} else {
lhs = "\t when";
}
String rhs = (String) ruleDescr.getConsequence();
if ( rhs == null ) {
rhs = "\t then" + DrlDumper.eol + "\t";
} else {
rhs = "\t then" + DrlDumper.eol + ruleDescr.getConsequence();
}
rule += attribute;
rule += lhs;
rule += rhs;
rule += "end" + DrlDumper.eol;
ruleList += rule;
}
return ruleList + DrlDumper.eol;
}
private String processOrDescrList(final List descr) {
String descrString = "";
for ( final Iterator iterator = descr.iterator(); iterator.hasNext(); ) {
visit( iterator.next() );
descrString += this.template;
if ( descrString.endsWith( DrlDumper.eol ) ) {
descrString = descrString.substring( 0,
descrString.indexOf( DrlDumper.eol ) );
}
descrString += " || ";
}
return descrString.substring( 0,
descrString.length() - 4 );
}
private String processColoumnConstraintList(final List descr) {
String descrString = "";
Object previous = null;
for ( final Iterator iterator = descr.iterator(); iterator.hasNext(); ) {
final Object temp = iterator.next();
visit( temp );
if ( previous == null ) {
descrString += this.template;
} else if ( previous instanceof FieldBindingDescr && !(temp instanceof FieldBindingDescr) && !(temp instanceof PredicateDescr) ) {
final FieldConstraintDescr tempDescr = (FieldConstraintDescr) temp;
final FieldBindingDescr previousDescr = (FieldBindingDescr) previous;
if ( tempDescr.getFieldName().equals( previousDescr.getFieldName() ) ) {
// as its a binding followed by a field constraint we need to remove
// the extra field name
descrString += this.template.substring( tempDescr.getFieldName().length() + 1 );
} else {
descrString += " , " + this.template;
}
} else {
descrString += " , " + this.template;
}
previous = temp;
}
return descrString.substring( 0,
descrString.length() );
}
private String processFieldConstraint(final RestrictionConnectiveDescr restriction,
boolean addBrackets) {
String descrString = "";
String connective = "";
boolean bracketTmp = this.needsBracket;
this.needsBracket = restriction.getRestrictions().size() > 1;
if ( restriction.getConnective() == RestrictionConnectiveDescr.OR ) {
connective = " || ";
} else {
connective = " && ";
}
if ( addBrackets && bracketTmp ) {
descrString += "( ";
}
for ( final Iterator it = restriction.getRestrictions().iterator(); it.hasNext(); ) {
final Object temp = it.next();
visit( temp );
descrString += this.template;
if ( it.hasNext() ) {
descrString += connective;
}
}
if ( addBrackets && bracketTmp ) {
descrString += " )";
}
this.needsBracket = bracketTmp;
return descrString;
}
private String processDescrList(final List descr) {
String descrString = "";
for ( final Iterator ite = descr.iterator(); ite.hasNext(); ) {
Object obj = ite.next();
visit( obj );
descrString += this.template;
if ( obj.getClass().equals( PatternDescr.class ) || obj.getClass().equals( CollectDescr.class ) ) {
descrString += DrlDumper.eol;
} else if ( ite.hasNext() ) {
descrString += " && ";
}
}
return descrString;
}
private String processFunctionsList(final List functions) {
String functionList = "";
for ( final Iterator it = functions.iterator(); it.hasNext(); ) {
visit( it.next() );
functionList += this.template;
}
return functionList + DrlDumper.eol;
}
private String processAttribute(final List attributes) {
String attributeList = "";
for ( final Iterator it = attributes.iterator(); it.hasNext(); ) {
final AttributeDescr attributeDescr = (AttributeDescr) it.next();
visit( attributeDescr );
attributeList += this.template;
}
return attributeList;
}
private String processParameters(final List parameterNames,
final List parameterTypes) {
if ( parameterNames.isEmpty() ) {
return "";
}
String paramList = "";
int i = 0;
for ( final Iterator it = parameterNames.iterator(); it.hasNext(); i++ ) {
final String paramName = (String) it.next();
final String paramType = (String) parameterTypes.get( i );
final String paramTemplate = paramType + " " + paramName + ",";
paramList += paramTemplate;
}
paramList = paramList.substring( 0,
paramList.length() - 1 );
return paramList;
}
private String processGlobalsList(final List globals) {
String globalList = "";
for ( final Iterator it = globals.iterator(); it.hasNext(); ) {
final GlobalDescr global = (GlobalDescr) it.next();
final String identifier = global.getIdentifier();
final String type = global.getType();
final String globalTemplate = "global " + type + " " + identifier + ";" + DrlDumper.eol;
globalList += globalTemplate;
}
return globalList + DrlDumper.eol;
}
private String processFunctionImportsList(final List imports) {
String importList = "";
for ( final Iterator it = imports.iterator(); it.hasNext(); ) {
final String importString = ((FunctionImportDescr) it.next()).getTarget();
final String importTemplate = "import function " + importString + ";" + DrlDumper.eol;
importList += importTemplate;
}
return importList + DrlDumper.eol;
}
private String processImportsList(final List imports) {
String importList = "";
for ( final Iterator it = imports.iterator(); it.hasNext(); ) {
final ImportDescr importDescr = (ImportDescr) it.next();
final String importTemplate = "import " + importDescr.getTarget() + ";" + DrlDumper.eol;
importList += importTemplate;
}
return importList + DrlDumper.eol;
}
private void appendDrlDump(final String temp) {
this.drlDump.append( temp );
}
}