/*
 * Hibernate Validator, declare and validate application constraints
 *
 * License: Apache License, Version 2.0
 * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
 */
package org.hibernate.validator.internal.metadata.location;

import java.lang.reflect.Executable;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;

import org.hibernate.validator.internal.engine.path.PathImpl;
import org.hibernate.validator.internal.util.ExecutableParameterNameProvider;

Represents the location (e.g. a bean, field or method parameter) of a constraint and provides logic related to it,
e.g. for appending the location to a given property path.

Note that while the validation engine works on the aggregated meta-model (which e.g. provides a unified view for
properties, be them represented via fields or getter methods) most of the time, in some situations the physical
element which hosts a constraint is relevant. This includes

retrieval of property values to be validated (either field or getter access)
constraint validator resolution; a field and the corresponding getter method may have different types, causing
potentially different validators to kick in for the constraints declared on either element
determination of a constraint's scope (locally defined or up in the hierarchy)

Author:
Hardy Ferentschik, Gunnar Morling/**
 * Represents the location (e.g. a bean, field or method parameter) of a constraint and provides logic related to it,
 * e.g. for appending the location to a given property path.
 * <p>
 * Note that while the validation engine works on the aggregated meta-model (which e.g. provides a unified view for
 * properties, be them represented via fields or getter methods) most of the time, in some situations the physical
 * element which hosts a constraint is relevant. This includes
 * <ul>
 * <li>retrieval of property values to be validated (either field or getter access)</li>
 * <li>constraint validator resolution; a field and the corresponding getter method may have different types, causing
 * potentially different validators to kick in for the constraints declared on either element</li>
 * <li>determination of a constraint's scope (locally defined or up in the hierarchy)</li>
 * </ul>
 *
 * @author Hardy Ferentschik
 * @author Gunnar Morling
 */
public interface ConstraintLocation {

	static ConstraintLocation forClass(Class<?> declaringClass) {
		return new BeanConstraintLocation( declaringClass );
	}

	static ConstraintLocation forField(Field field) {
		return new FieldConstraintLocation( field );
	}

	
Create a new GetterConstraintLocation for the given getter method. 
Params:
getter – The getter method being constrained
Returns:
A new GetterConstraintLocation/**
	 * Create a new {@link GetterConstraintLocation} for the given getter method.
	 *
	 * @param getter The getter method being constrained
	 * @return A new GetterConstraintLocation
	 */
	static ConstraintLocation forGetter(Method getter) {
		return new GetterConstraintLocation( getter.getDeclaringClass(), getter );
	}

	
Create a new GetterConstraintLocation for the given declaring class and getter method. 
 This provides an alternative to forGetter(Method) where the given declaring class is usually a sub-class of the actual class on which the getter method is declared. This is provided to support XML mapping configurations used to specify constraints on subclasses for inherited getter methods. 
Params:
declaringClass – The class on which the constraint is defined.
getter – The getter method being constrained.
Returns:
A new GetterConstraintLocation/**
	 * Create a new {@link GetterConstraintLocation} for the given declaring class and getter method.
	 * <p>
	 * This provides an alternative to {@link ConstraintLocation#forGetter(Method)} where the given declaring class is usually a sub-class of the
	 * actual class on which the getter method is declared. This is provided to support XML mapping configurations used to specify constraints on
	 * subclasses for inherited getter methods.
	 *
	 * @param declaringClass The class on which the constraint is defined.
	 * @param getter The getter method being constrained.
	 * @return A new GetterConstraintLocation
	 */
	static ConstraintLocation forGetter(Class<?> declaringClass, Method getter ) {
		return new GetterConstraintLocation( declaringClass, getter );
	}

	static ConstraintLocation forTypeArgument(ConstraintLocation delegate, TypeVariable<?> typeParameter, Type typeOfAnnotatedElement) {
		return new TypeArgumentConstraintLocation( delegate, typeParameter, typeOfAnnotatedElement );
	}

	static ConstraintLocation forReturnValue(Executable executable) {
		return new ReturnValueConstraintLocation( executable );
	}

	static ConstraintLocation forCrossParameter(Executable executable) {
		return new CrossParameterConstraintLocation( executable );
	}

	static ConstraintLocation forParameter(Executable executable, int index) {
		return new ParameterConstraintLocation( executable, index );
	}

	
Returns the class hosting this location.
/**
	 * Returns the class hosting this location.
	 */
	Class<?> getDeclaringClass();

	
Returns the member represented by this location.
Returns:
the member represented by this location. Will be null when this location represents a type./**
	 * Returns the member represented by this location.
	 *
	 * @return the member represented by this location. Will be {@code null} when this location represents a type.
	 */
	Member getMember();

	
Returns the type to be used when resolving constraint validators for constraints at this location. Note that this
is not always the same type as the type of the element described by this location; E.g. the wrapper type will is
used for constraint validator resolution, if a constraint is declared in an element with a primitive type.
Returns:
The type to be used when resolving constraint validators for constraints at this location/**
	 * Returns the type to be used when resolving constraint validators for constraints at this location. Note that this
	 * is not always the same type as the type of the element described by this location; E.g. the wrapper type will is
	 * used for constraint validator resolution, if a constraint is declared in an element with a primitive type.
	 *
	 * @return The type to be used when resolving constraint validators for constraints at this location
	 */
	Type getTypeForValidatorResolution();

	
Appends a node representing this location to the given property path.
/**
	 * Appends a node representing this location to the given property path.
	 */
	void appendTo(ExecutableParameterNameProvider parameterNameProvider, PathImpl path);

	
Obtains the value of this location from the parent. The type of the passed parent depends on the location type, e.g. a bean would be passed for a FieldConstraintLocation or GetterConstraintLocation but an object array for a ParameterConstraintLocation. /**
	 * Obtains the value of this location from the parent. The type of the passed parent depends on the location type,
	 * e.g. a bean would be passed for a {@link FieldConstraintLocation} or {@link GetterConstraintLocation} but an
	 * object array for a {@link ParameterConstraintLocation}.
	 */
	Object getValue(Object parent);
}