RuleModelPeerVariableVisitor.java

/*
 * Copyright 2012 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.workbench.screens.guided.template.client.editor;

import java.util.ArrayList;
import java.util.List;

import org.drools.workbench.models.datamodel.rule.ActionFieldList;
import org.drools.workbench.models.datamodel.rule.ActionFieldValue;
import org.drools.workbench.models.datamodel.rule.BaseSingleFieldConstraint;
import org.drools.workbench.models.datamodel.rule.CompositeFactPattern;
import org.drools.workbench.models.datamodel.rule.CompositeFieldConstraint;
import org.drools.workbench.models.datamodel.rule.FactPattern;
import org.drools.workbench.models.datamodel.rule.FieldConstraint;
import org.drools.workbench.models.datamodel.rule.FieldNatureType;
import org.drools.workbench.models.datamodel.rule.FromAccumulateCompositeFactPattern;
import org.drools.workbench.models.datamodel.rule.FromCollectCompositeFactPattern;
import org.drools.workbench.models.datamodel.rule.FromCompositeFactPattern;
import org.drools.workbench.models.datamodel.rule.IAction;
import org.drools.workbench.models.datamodel.rule.IPattern;
import org.drools.workbench.models.datamodel.rule.RuleModel;
import org.drools.workbench.models.datamodel.rule.SingleFieldConstraint;
import org.drools.workbench.models.datamodel.rule.SingleFieldConstraintEBLeftSide;

/**
 * A Rule Model Visitor to extract InterpolationVariables that are defined on
 * the same Pattern or Action as the provided base variable. This is used to get
 * a list of InterpolationVariables (or literal values) used to drive dependent
 * enumerations.
 */
public class RuleModelPeerVariableVisitor {

    private final RuleModel model;
    private final String    baseVariableName;
    private final List<ValueHolder> peerVariables = new ArrayList<ValueHolder>();

    //Container for extracted InterpolationVariable or literal value
    public static class ValueHolder {

        private final String fieldName;
        private final String value;
        private final Type   type;

        public enum Type {
            VALUE,
            TEMPLATE_KEY
        }

        ValueHolder( String fieldName,
                     String value,
                     Type type ) {
            this.fieldName = fieldName;
            this.value = value;
            this.type = type;
        }

        public String getFieldName() {
            return this.fieldName;
        }

        public String getValue() {
            return this.value;
        }

        public Type getType() {
            return this.type;
        }
    }

    public RuleModelPeerVariableVisitor( final RuleModel model,
                                         final String baseVariableName ) {
        this.model = model;
        this.baseVariableName = baseVariableName;
    }

    public List<ValueHolder> getPeerVariables() {
        visit( this.model );
        return this.peerVariables;
    }

    private void visit( Object o ) {
        if ( o == null ) {
            return;
        }
        if ( o instanceof RuleModel ) {
            visitRuleModel( (RuleModel) o );
        } else if ( o instanceof FactPattern ) {
            visitFactPattern( (FactPattern) o );
        } else if ( o instanceof CompositeFieldConstraint ) {
            visitCompositeFieldConstraint( (CompositeFieldConstraint) o );
        } else if ( o instanceof SingleFieldConstraintEBLeftSide ) {
            visitSingleFieldConstraint( (SingleFieldConstraintEBLeftSide) o );
        } else if ( o instanceof SingleFieldConstraint ) {
            visitSingleFieldConstraint( (SingleFieldConstraint) o );
        } else if ( o instanceof CompositeFactPattern ) {
            visitCompositeFactPattern( (CompositeFactPattern) o );
        } else if ( o instanceof FromAccumulateCompositeFactPattern ) {
            visitFromAccumulateCompositeFactPattern( (FromAccumulateCompositeFactPattern) o );
        } else if ( o instanceof FromCollectCompositeFactPattern ) {
            visitFromCollectCompositeFactPattern( (FromCollectCompositeFactPattern) o );
        } else if ( o instanceof FromCompositeFactPattern ) {
            visitFromCompositeFactPattern( (FromCompositeFactPattern) o );
        } else if ( o instanceof ActionFieldList ) {
            visitActionFieldList( (ActionFieldList) o );
        }
    }

    private void visitRuleModel( final RuleModel rm ) {
        for ( IPattern p : rm.lhs ) {
            visit( p );
        }
        for ( IAction a : rm.rhs ) {
            visit( a );
        }
    }

    private void visitFactPattern( final FactPattern fp ) {
        if ( isParentFactPattern( fp ) ) {
            for ( FieldConstraint fc : fp.getFieldConstraints() ) {
                visit( fc );
            }
        }
    }

    private boolean isParentFactPattern( final FactPattern fp ) {
        for ( FieldConstraint fc : fp.getFieldConstraints() ) {
            if ( isParentFactPattern( fc ) ) {
                return true;
            }
        }
        return false;
    }

    private boolean isParentFactPattern( FieldConstraint fc ) {
        if ( fc instanceof SingleFieldConstraint ) {
            final SingleFieldConstraint sfc = (SingleFieldConstraint) fc;
            return isParentFactPattern( sfc );
        } else if ( fc instanceof CompositeFieldConstraint ) {
            final CompositeFieldConstraint cfc = (CompositeFieldConstraint) fc;
            return isParentFactPattern( cfc );
        }
        return false;
    }

    private boolean isParentFactPattern( final SingleFieldConstraint sfc ) {
        if ( sfc.getConstraintValueType() == BaseSingleFieldConstraint.TYPE_TEMPLATE ) {
            if ( sfc.getValue().equals( this.baseVariableName ) ) {
                return true;
            }
        }
        return false;
    }

    private boolean isParentFactPattern( final CompositeFieldConstraint cfc ) {
        if ( cfc.getCompositeJunctionType().equals( CompositeFieldConstraint.COMPOSITE_TYPE_AND ) ) {
            for ( FieldConstraint fc : cfc.getConstraints() ) {
                if ( isParentFactPattern( fc ) ) {
                    return true;
                }
            }
        }
        return false;
    }

    private void visitCompositeFactPattern( final CompositeFactPattern cfp ) {
        for ( IPattern p : cfp.getPatterns() ) {
            visit( p );
        }
    }

    private void visitCompositeFieldConstraint( final CompositeFieldConstraint cfc ) {
        for ( FieldConstraint fc : cfc.getConstraints() ) {
            visit( fc );
        }
    }

    private void visitFromAccumulateCompositeFactPattern( final FromAccumulateCompositeFactPattern pattern ) {
        if ( pattern.getFactPattern() != null ) {
            visit( pattern.getFactPattern() );
        }
    }

    private void visitFromCollectCompositeFactPattern( final FromCollectCompositeFactPattern pattern ) {
        if ( pattern.getFactPattern() != null ) {
            visit( pattern.getFactPattern() );
        }
    }

    private void visitFromCompositeFactPattern( final FromCompositeFactPattern pattern ) {
        if ( pattern.getFactPattern() != null ) {
            visit( pattern.getFactPattern() );
        }
    }

    private void visitSingleFieldConstraint( final SingleFieldConstraint sfc ) {
        if ( sfc.getConstraintValueType() == BaseSingleFieldConstraint.TYPE_TEMPLATE ) {
            this.peerVariables.add( new ValueHolder( sfc.getFieldName(),
                                                     sfc.getValue(),
                                                     ValueHolder.Type.TEMPLATE_KEY ) );
        } else {
            this.peerVariables.add( new ValueHolder( sfc.getFieldName(),
                                                     sfc.getValue(),
                                                     ValueHolder.Type.VALUE ) );
        }
    }

    private void visitSingleFieldConstraint( final SingleFieldConstraintEBLeftSide sfexp ) {
        if ( sfexp.getConstraintValueType() == BaseSingleFieldConstraint.TYPE_TEMPLATE ) {
            this.peerVariables.add( new ValueHolder( sfexp.getFieldName(),
                                                     sfexp.getValue(),
                                                     ValueHolder.Type.TEMPLATE_KEY ) );
        } else {
            this.peerVariables.add( new ValueHolder( sfexp.getFieldName(),
                                                     sfexp.getValue(),
                                                     ValueHolder.Type.VALUE ) );
        }
    }

    private void visitActionFieldList( final ActionFieldList afl ) {
        boolean addVariables = false;
        List<ValueHolder> variables = new ArrayList<ValueHolder>();
        for ( ActionFieldValue afv : afl.getFieldValues() ) {
            if ( afv.getNature() == FieldNatureType.TYPE_TEMPLATE ) {
                if ( afv.getValue().equals( this.baseVariableName ) ) {
                    addVariables = true;
                }
                ValueHolder vh = new ValueHolder( afv.getField(),
                                                  afv.getValue(),
                                                  ValueHolder.Type.TEMPLATE_KEY );
                variables.add( vh );
            } else {
                ValueHolder vh = new ValueHolder( afv.getField(),
                                                  afv.getValue(),
                                                  ValueHolder.Type.VALUE );
                variables.add( vh );
            }
        }
        if ( addVariables ) {
            this.peerVariables.addAll( variables );
        }

    }

}