package org.drools.compiler.rule.builder;
import org.drools.compiler.compiler.DroolsError;
import org.drools.compiler.compiler.RuleBuildError;
import org.drools.compiler.lang.descr.BaseDescr;
import org.drools.compiler.lang.descr.ConditionalBranchDescr;
import org.drools.compiler.lang.descr.EvalDescr;
import org.drools.compiler.lang.descr.NamedConsequenceDescr;
import org.drools.core.definitions.rule.impl.RuleImpl;
import org.drools.core.rule.ConditionalBranch;
import org.drools.core.rule.EvalCondition;
import org.drools.core.rule.GroupElement;
import org.drools.core.rule.NamedConsequence;
import org.drools.core.rule.Pattern;
import org.drools.core.rule.RuleConditionElement;
import java.util.List;
public class ConditionalBranchBuilder implements RuleConditionBuilder {
public ConditionalBranch build(RuleBuildContext context, BaseDescr descr) {
return build( context, descr, null );
}
public ConditionalBranch build(RuleBuildContext context, BaseDescr descr, Pattern prefixPattern) {
ConditionalBranchDescr conditionalBranch = (ConditionalBranchDescr) descr;
String consequenceName = conditionalBranch.getConsequence().getName();
if ( !context.getRuleDescr().getNamedConsequences().keySet().contains( consequenceName ) ) {
DroolsError err = new RuleBuildError( context.getRule(), context.getParentDescr(), null,
"Unknown consequence name: " + consequenceName );
context.addError( err );
return null;
}
RuleConditionBuilder evalBuilder = (RuleConditionBuilder) context.getDialect().getBuilder( EvalDescr.class );
EvalCondition condition = (EvalCondition) evalBuilder.build(context, conditionalBranch.getCondition(), getLastPattern(context));
NamedConsequenceBuilder namedConsequenceBuilder = (NamedConsequenceBuilder) context.getDialect().getBuilder( NamedConsequenceDescr.class );
NamedConsequence consequence = namedConsequenceBuilder.build(context, conditionalBranch.getConsequence());
ConditionalBranchDescr elseBranchDescr = conditionalBranch.getElseBranch();
return new ConditionalBranch( condition, consequence, elseBranchDescr != null ? build(context, elseBranchDescr, prefixPattern) : null );
}
private Pattern getLastPattern(RuleBuildContext context) {
GroupElement ge = (GroupElement)context.getBuildStack().peek();
Pattern lastPattern = getLastPattern(ge.getChildren());
if (lastPattern == null) {
RuleImpl parent = context.getRule().getParent();
if (parent != null) {
lastPattern = getLastPattern(parent.getLhs().getChildren());
}
}
return lastPattern;
}
private Pattern getLastPattern(List<RuleConditionElement> siblings) {
for (int i = siblings.size()-1; i >= 0; i--) {
RuleConditionElement element = siblings.get(i);
if (element instanceof Pattern) {
return (Pattern) element;
}
}
return null;
}
}