HSEARCH-4574 Move projection constructor binding to dedicated classes

To prepare for the introduction of projection binders.

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/search/definition/binding/impl/ProjectionConstructorBinder.java

@@ -0,0 +1,108 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.mapper.pojo.search.definition.binding.impl;
+
+import java.lang.invoke.MethodHandles;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hibernate.search.engine.backend.common.spi.FieldPaths;
+import org.hibernate.search.mapper.pojo.logging.impl.Log;
+import org.hibernate.search.mapper.pojo.mapping.building.impl.PojoMappingHelper;
+import org.hibernate.search.mapper.pojo.model.spi.PojoConstructorModel;
+import org.hibernate.search.mapper.pojo.model.spi.PojoMethodParameterModel;
+import org.hibernate.search.mapper.pojo.reporting.spi.PojoEventContexts;
+import org.hibernate.search.mapper.pojo.search.definition.impl.InnerProjectionDefinition;
+import org.hibernate.search.mapper.pojo.search.definition.impl.NullInnerProjectionDefinition;
+import org.hibernate.search.mapper.pojo.search.definition.impl.PojoConstructorProjectionDefinition;
+import org.hibernate.search.util.common.logging.impl.LoggerFactory;
+import org.hibernate.search.util.common.reporting.EventContext;
+import org.hibernate.search.util.common.reporting.spi.EventContextProvider;
+
+public class ProjectionConstructorBinder<T> implements EventContextProvider {
+
+	private static final Log log = LoggerFactory.make( Log.class, MethodHandles.lookup() );
+	private final PojoMappingHelper mappingHelper;
+	private final ProjectionConstructorParameterBinder<?> parent;
+	private final String relativeFieldPath;
+	final String absoluteFieldPath;
+	final PojoConstructorModel<T> constructor;
+
+	public ProjectionConstructorBinder(PojoMappingHelper mappingHelper, PojoConstructorModel<T> constructor) {
+		this( mappingHelper, constructor, null, null );
+	}
+
+	ProjectionConstructorBinder(PojoMappingHelper mappingHelper, PojoConstructorModel<T> constructor,
+			ProjectionConstructorParameterBinder<?> parent, String relativeFieldPath) {
+		this.mappingHelper = mappingHelper;
+		this.parent = parent;
+		this.relativeFieldPath = relativeFieldPath;
+		this.absoluteFieldPath = FieldPaths.compose( parent == null ? null : parent.parent.absoluteFieldPath,
+				relativeFieldPath );
+		this.constructor = constructor;
+	}
+
+	@Override
+	public EventContext eventContext() {
+		return EventContext.concat(
+				parent == null ? null : parent.eventContext(),
+				PojoEventContexts.fromType( constructor.typeModel() ),
+				PojoEventContexts.fromConstructor( constructor )
+		);
+	}
+
+	public PojoConstructorProjectionDefinition<T> bind() {
+		if ( constructor.typeModel().isAbstract() ) {
+			throw log.invalidAbstractTypeForProjectionConstructor(
+					constructor.typeModel() );
+		}
+		if ( parent != null ) {
+			String path = parent.parent.getPathFromSameProjectionConstructor( constructor );
+			if ( path != null ) {
+				throw log.infiniteRecursionForProjectionConstructor(
+						constructor,
+						FieldPaths.compose( path, relativeFieldPath )
+				);
+			}
+		}
+		List<InnerProjectionDefinition> innerDefinitions = new ArrayList<>();
+		for ( PojoMethodParameterModel<?> parameter : constructor.declaredParameters() ) {
+			ProjectionConstructorParameterBinder<?> parameterNode =
+					new ProjectionConstructorParameterBinder<>(
+							mappingHelper, this, parameter );
+			InnerProjectionDefinition innerProjection;
+			try {
+				innerProjection = parameterNode.bind();
+			}
+			catch (RuntimeException e) {
+				mappingHelper.failureCollector()
+						.withContext( parameterNode.eventContext() )
+						.add( e );
+				// Here the result no longer matters, bootstrap will fail anyway.
+				// We just pick a neutral value that won't trigger cascading failures.
+				innerProjection = NullInnerProjectionDefinition.INSTANCE;
+			}
+			innerDefinitions.add( innerProjection );
+		}
+		return new PojoConstructorProjectionDefinition<>( constructor, innerDefinitions );
+	}
+
+	private String getPathFromSameProjectionConstructor(PojoConstructorModel<?> constructorToMatch) {
+		if ( this.constructor.equals( constructorToMatch ) ) {
+			return "";
+		}
+		else if ( parent != null ) {
+			String path = parent.parent.getPathFromSameProjectionConstructor( constructorToMatch );
+			return path == null ? null : FieldPaths.compose( path, relativeFieldPath );
+		}
+		else {
+			// This is the root.
+			// If we reach this point, no definition involving the given projection constructor was found.
+			return null;
+		}
+	}
+}

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/search/definition/binding/impl/ProjectionConstructorParameterBinder.java

@@ -0,0 +1,126 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.mapper.pojo.search.definition.binding.impl;
+
+import java.lang.invoke.MethodHandles;
+import java.util.List;
+import java.util.Optional;
+
+import org.hibernate.search.engine.backend.common.spi.FieldPaths;
+import org.hibernate.search.mapper.pojo.extractor.builtin.BuiltinContainerExtractors;
+import org.hibernate.search.mapper.pojo.extractor.impl.BoundContainerExtractorPath;
+import org.hibernate.search.mapper.pojo.extractor.mapping.programmatic.ContainerExtractorPath;
+import org.hibernate.search.mapper.pojo.logging.impl.Log;
+import org.hibernate.search.mapper.pojo.mapping.building.impl.PojoMappingHelper;
+import org.hibernate.search.mapper.pojo.mapping.building.spi.PojoSearchMappingConstructorNode;
+import org.hibernate.search.mapper.pojo.mapping.building.spi.PojoTypeMetadataContributor;
+import org.hibernate.search.mapper.pojo.model.spi.PojoConstructorModel;
+import org.hibernate.search.mapper.pojo.model.spi.PojoMethodParameterModel;
+import org.hibernate.search.mapper.pojo.model.spi.PojoRawTypeModel;
+import org.hibernate.search.mapper.pojo.model.spi.PojoTypeModel;
+import org.hibernate.search.mapper.pojo.reporting.spi.PojoEventContexts;
+import org.hibernate.search.mapper.pojo.search.definition.impl.InnerProjectionDefinition;
+import org.hibernate.search.mapper.pojo.search.definition.impl.NullInnerProjectionDefinition;
+import org.hibernate.search.mapper.pojo.search.definition.impl.ObjectInnerProjectionDefinition;
+import org.hibernate.search.mapper.pojo.search.definition.impl.PojoConstructorProjectionDefinition;
+import org.hibernate.search.mapper.pojo.search.definition.impl.ValueInnerProjectionDefinition;
+import org.hibernate.search.util.common.logging.impl.LoggerFactory;
+import org.hibernate.search.util.common.reporting.EventContext;
+import org.hibernate.search.util.common.reporting.spi.EventContextProvider;
+
+class ProjectionConstructorParameterBinder<P> implements EventContextProvider {
+
+	private static final Log log = LoggerFactory.make( Log.class, MethodHandles.lookup() );
+	private final PojoMappingHelper mappingHelper;
+	final ProjectionConstructorBinder<?> parent;
+	private final PojoMethodParameterModel<P> parameter;
+
+	ProjectionConstructorParameterBinder(PojoMappingHelper mappingHelper, ProjectionConstructorBinder<?> parent,
+			PojoMethodParameterModel<P> parameter) {
+		this.mappingHelper = mappingHelper;
+		this.parent = parent;
+		this.parameter = parameter;
+	}
+
+	@Override
+	public EventContext eventContext() {
+		return parent.eventContext().append( PojoEventContexts.fromMethodParameter( parameter ) );
+	}
+
+	InnerProjectionDefinition bind() {
+		if ( parameter.isEnclosingInstance() ) {
+			// Let's ignore this parameter, because we are not able to provide a surrounding instance,
+			// and it's often useful to be able to declare a method-local type for projections
+			// (those types have a "surrounding instance" parameter in their constructor
+			// even if they don't use it).
+			return NullInnerProjectionDefinition.INSTANCE;
+		}
+		PojoTypeModel<P> parameterType = parameter.typeModel();
+		BoundContainerExtractorPath<?, ?> boundParameterElementPath = mappingHelper.indexModelBinder()
+				.bindExtractorPath( parameter.typeModel(), ContainerExtractorPath.defaultExtractors() );
+		List<String> boundParameterElementExtractorNames =
+				boundParameterElementPath.getExtractorPath().explicitExtractorNames();
+
+		boolean multi;
+		if ( boundParameterElementExtractorNames.isEmpty() ) {
+			multi = false;
+		}
+		else {
+			if ( boundParameterElementExtractorNames.size() > 1
+					|| !( BuiltinContainerExtractors.COLLECTION.equals( boundParameterElementExtractorNames.get( 0 ) )
+					|| BuiltinContainerExtractors.ITERABLE.equals( boundParameterElementExtractorNames.get( 0 ) ) )
+					|| !mappingHelper.introspector().typeModel( List.class ).isSubTypeOf(
+					parameterType.rawType().rawType() ) ) {
+				throw log.invalidMultiValuedParameterTypeForProjectionConstructor(
+						parameterType );
+			}
+			multi = true;
+		}
+
+		PojoRawTypeModel<?> boundParameterElementRawType = boundParameterElementPath.getExtractedType().rawType();
+		Optional<String> paramName = parameter.name();
+		if ( !paramName.isPresent() ) {
+			throw log.missingParameterNameForProjectionConstructor();
+		}
+		String innerRelativeFieldPath = paramName.get();
+		String innerAbsoluteFieldPath = FieldPaths.compose( parent.absoluteFieldPath, innerRelativeFieldPath );
+		PojoConstructorProjectionDefinition<?> definition = createConstructorProjectionDefinitionOrNull(
+				boundParameterElementRawType, innerRelativeFieldPath );
+		if ( definition != null ) {
+			return new ObjectInnerProjectionDefinition( innerAbsoluteFieldPath, multi, definition );
+		}
+		else {
+			// No projection constructor for this type; assume it's a projection on value field
+			return new ValueInnerProjectionDefinition( innerAbsoluteFieldPath, multi,
+					boundParameterElementRawType.typeIdentifier().javaClass()
+			);
+		}
+	}
+
+	<T> PojoConstructorProjectionDefinition<T> createConstructorProjectionDefinitionOrNull(
+			PojoRawTypeModel<T> parameterType,
+			String relativeFieldPath) {
+		PojoConstructorProjectionDefinition<T> result = null;
+		for ( PojoTypeMetadataContributor contributor : mappingHelper.contributorProvider()
+				// Constructor mapping is not inherited
+				.getIgnoringInheritance( parameterType ) ) {
+			for ( PojoSearchMappingConstructorNode constructorMapping : contributor.constructors().values() ) {
+				if ( constructorMapping.isProjectionConstructor() ) {
+					if ( result != null ) {
+						throw log.multipleProjectionConstructorsForType(
+								parameterType.typeIdentifier().javaClass() );
+					}
+					PojoConstructorModel<T> constructor = parameterType.constructor(
+							constructorMapping.parametersJavaTypes() );
+					result = new ProjectionConstructorBinder<>( mappingHelper, constructor, this, relativeFieldPath )
+							.bind();
+				}
+			}
+		}
+		return result;
+	}
+}

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/search/definition/impl/InnerProjectionDefinition.java

@@ -10,7 +10,7 @@
 import org.hibernate.search.engine.search.projection.dsl.SearchProjectionFactory;
 import org.hibernate.search.util.common.spi.ToStringTreeAppendable;
 
-interface InnerProjectionDefinition extends ToStringTreeAppendable {
+public interface InnerProjectionDefinition extends ToStringTreeAppendable {
 
 	SearchProjection<?> create(SearchProjectionFactory<?, ?> f);
 

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/search/definition/impl/NullInnerProjectionDefinition.java

@@ -10,9 +10,9 @@
 import org.hibernate.search.engine.search.projection.dsl.SearchProjectionFactory;
 import org.hibernate.search.util.common.spi.ToStringTreeAppender;
 
-final class NullInnerProjectionDefinition
+public final class NullInnerProjectionDefinition
 		implements InnerProjectionDefinition {
-	static final NullInnerProjectionDefinition INSTANCE = new NullInnerProjectionDefinition();
+	public static final NullInnerProjectionDefinition INSTANCE = new NullInnerProjectionDefinition();
 
 	private NullInnerProjectionDefinition() {
 	}

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/search/definition/impl/ObjectInnerProjectionDefinition.java

@@ -11,12 +11,12 @@
 import org.hibernate.search.engine.search.projection.dsl.SearchProjectionFactory;
 import org.hibernate.search.util.common.spi.ToStringTreeAppender;
 
-final class ObjectInnerProjectionDefinition implements InnerProjectionDefinition {
+public final class ObjectInnerProjectionDefinition implements InnerProjectionDefinition {
 	final String path;
 	final boolean multi;
 	final CompositeProjectionDefinition<?> composite;
 
-	ObjectInnerProjectionDefinition(String path, boolean multi, CompositeProjectionDefinition<?> composite) {
+	public ObjectInnerProjectionDefinition(String path, boolean multi, CompositeProjectionDefinition<?> composite) {
 		this.path = path;
 		this.multi = multi;
 		this.composite = composite;