/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.epl.expression;
import com.espertech.esper.client.PropertyAccessException;
import com.espertech.esper.collection.Pair;
import com.espertech.esper.epl.core.PropertyResolutionDescriptor;
import com.espertech.esper.epl.core.StreamTypeService;
import com.espertech.esper.epl.core.StreamTypesException;
import com.espertech.esper.util.LevenshteinDistance;
public class ExprIdentNodeUtil
{
/**
* Determine stream id and property type given an unresolved property name and
* a stream name that may also be part of the property name.
* <p>
* For example: select s0.p1 from... p1 is the property name, s0 the stream name, however this could also be a nested property
* @param streamTypeService - service for type infos
* @param unresolvedPropertyName - property name
* @param streamOrPropertyName - stream name, this can also be the first part of the property name
* @return pair of stream number and property type
* @throws ExprValidationPropertyException if no such property exists
*/
protected static Pair<PropertyResolutionDescriptor, String> getTypeFromStream(StreamTypeService streamTypeService, String unresolvedPropertyName, String streamOrPropertyName)
throws ExprValidationPropertyException
{
PropertyResolutionDescriptor propertyInfo;
// no stream/property name supplied
if (streamOrPropertyName == null)
{
try
{
propertyInfo = streamTypeService.resolveByPropertyName(unresolvedPropertyName);
}
catch (StreamTypesException ex)
{
throw getSuggestionException(ex);
}
catch (PropertyAccessException ex)
{
throw new ExprValidationPropertyException(ex.getMessage());
}
// resolves without a stream name, return descriptor and null stream name
return new Pair<PropertyResolutionDescriptor, String>(propertyInfo, propertyInfo.getStreamName());
}
// try to resolve the property name and stream name as it is (ie. stream name as a stream name)
StreamTypesException typeExceptionOne;
try
{
propertyInfo = streamTypeService.resolveByStreamAndPropName(streamOrPropertyName, unresolvedPropertyName);
// resolves with a stream name, return descriptor and stream name
return new Pair<PropertyResolutionDescriptor, String>(propertyInfo, streamOrPropertyName);
}
catch (StreamTypesException ex)
{
typeExceptionOne = ex;
}
// try to resolve the property name to a nested property 's0.p0'
StreamTypesException typeExceptionTwo;
String propertyNameCandidate = streamOrPropertyName + '.' + unresolvedPropertyName;
try
{
propertyInfo = streamTypeService.resolveByPropertyName(propertyNameCandidate);
// resolves without a stream name, return null for stream name
return new Pair<PropertyResolutionDescriptor, String>(propertyInfo, null);
}
catch (StreamTypesException ex)
{
typeExceptionTwo = ex;
}
throw getSuggestionExceptionSecondStep(propertyNameCandidate, typeExceptionOne, typeExceptionTwo);
}
/**
* This method only resolves against explicitly-listed properties (for use with XML or other types that allow any name as a property name).
* @param streamTypeService stream types
* @param unresolvedPropertyName property name
* @param streamOrPropertyName optional stream name
* @return property info
* @throws ExprValidationPropertyException if the property could not be resolved
*/
protected static Pair<PropertyResolutionDescriptor, String> getTypeFromStreamExplicitProperties(StreamTypeService streamTypeService, String unresolvedPropertyName, String streamOrPropertyName)
throws ExprValidationPropertyException
{
PropertyResolutionDescriptor propertyInfo;
// no stream/property name supplied
if (streamOrPropertyName == null)
{
try
{
propertyInfo = streamTypeService.resolveByPropertyNameExplicitProps(unresolvedPropertyName);
}
catch (StreamTypesException ex)
{
throw getSuggestionException(ex);
}
catch (PropertyAccessException ex)
{
throw new ExprValidationPropertyException(ex.getMessage());
}
// resolves without a stream name, return descriptor and null stream name
return new Pair<PropertyResolutionDescriptor, String>(propertyInfo, propertyInfo.getStreamName());
}
// try to resolve the property name and stream name as it is (ie. stream name as a stream name)
StreamTypesException typeExceptionOne;
try
{
propertyInfo = streamTypeService.resolveByStreamAndPropNameExplicitProps(streamOrPropertyName, unresolvedPropertyName);
// resolves with a stream name, return descriptor and stream name
return new Pair<PropertyResolutionDescriptor, String>(propertyInfo, streamOrPropertyName);
}
catch (StreamTypesException ex)
{
typeExceptionOne = ex;
}
// try to resolve the property name to a nested property 's0.p0'
StreamTypesException typeExceptionTwo;
String propertyNameCandidate = streamOrPropertyName + '.' + unresolvedPropertyName;
try
{
propertyInfo = streamTypeService.resolveByPropertyNameExplicitProps(propertyNameCandidate);
// resolves without a stream name, return null for stream name
return new Pair<PropertyResolutionDescriptor, String>(propertyInfo, null);
}
catch (StreamTypesException ex)
{
typeExceptionTwo = ex;
}
throw getSuggestionExceptionSecondStep(propertyNameCandidate, typeExceptionOne, typeExceptionTwo);
}
private static ExprValidationPropertyException getSuggestionExceptionSecondStep(String propertyNameCandidate, StreamTypesException typeExceptionOne, StreamTypesException typeExceptionTwo) {
String suggestionOne = getSuggestion(typeExceptionOne);
String suggestionTwo = getSuggestion(typeExceptionTwo);
if (suggestionOne != null)
{
return new ExprValidationPropertyException(typeExceptionOne.getMessage() + suggestionOne);
}
if (suggestionTwo != null)
{
return new ExprValidationPropertyException(typeExceptionTwo.getMessage() + suggestionTwo);
}
// fail to resolve
return new ExprValidationPropertyException("Failed to resolve property '" + propertyNameCandidate + "' to a stream or nested property in a stream");
}
private static ExprValidationPropertyException getSuggestionException(StreamTypesException ex) {
String suggestion = getSuggestion(ex);
if (suggestion != null)
{
return new ExprValidationPropertyException(ex.getMessage() + suggestion);
}
else
{
return new ExprValidationPropertyException(ex.getMessage());
}
}
private static String getSuggestion(StreamTypesException ex)
{
if (ex == null)
{
return null;
}
if (ex.getOptionalSuggestion() == null)
{
return null;
}
if (ex.getOptionalSuggestion().getFirst() > LevenshteinDistance.ACCEPTABLE_DISTANCE)
{
return null;
}
return " (did you mean '" + ex.getOptionalSuggestion().getSecond() + "'?)";
}
}