/*
 * Copyright 2014 - 2020 Rafael Winterhalter
 *
 * 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 net.bytebuddy.implementation;

import net.bytebuddy.description.field.FieldDescription;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.modifier.Visibility;

A factory for creating method proxies for an auxiliary type. Such proxies are required to allow a type to
call methods of a second type that are usually not accessible for the first type. This strategy is also adapted
by the Java compiler that creates accessor methods for example to implement inner classes.
/**
 * A factory for creating method proxies for an auxiliary type. Such proxies are required to allow a type to
 * call methods of a second type that are usually not accessible for the first type. This strategy is also adapted
 * by the Java compiler that creates accessor methods for example to implement inner classes.
 */
public interface MethodAccessorFactory {

    
Registers an accessor method for a SpecialMethodInvocation which cannot itself be triggered invoked directly from outside a type. The method is registered on the instrumented type with package-private visibility, similarly to a Java compiler's accessor methods. 
Params:
specialMethodInvocation – The special method invocation.
accessType –              The required access type.
Returns:
The accessor method for invoking the special method invocation./**
     * Registers an accessor method for a
     * {@link Implementation.SpecialMethodInvocation} which cannot itself be
     * triggered invoked directly from outside a type. The method is registered on the instrumented type
     * with package-private visibility, similarly to a Java compiler's accessor methods.
     *
     * @param specialMethodInvocation The special method invocation.
     * @param accessType              The required access type.
     * @return The accessor method for invoking the special method invocation.
     */
    MethodDescription.InDefinedShape registerAccessorFor(Implementation.SpecialMethodInvocation specialMethodInvocation, AccessType accessType);

    
Registers a getter for the given FieldDescription which might itself not be accessible from outside the class. The returned getter method defines the field type as its return type, does not take any arguments and is of package-private visibility, similarly to the Java compiler's accessor methods. If the field is static, this accessor method is also static. 
Params:
fieldDescription – The field which is to be accessed.
accessType –       The required access type.
Returns:
A getter method for the given field./**
     * Registers a getter for the given {@link net.bytebuddy.description.field.FieldDescription} which might
     * itself not be accessible from outside the class. The returned getter method defines the field type as
     * its return type, does not take any arguments and is of package-private visibility, similarly to the Java
     * compiler's accessor methods. If the field is {@code static}, this accessor method is also {@code static}.
     *
     * @param fieldDescription The field which is to be accessed.
     * @param accessType       The required access type.
     * @return A getter method for the given field.
     */
    MethodDescription.InDefinedShape registerGetterFor(FieldDescription fieldDescription, AccessType accessType);

    
Registers a setter for the given FieldDescription which might itself not be accessible from outside the class. The returned setter method defines the field type as its only argument type, returns void and is of package-private visibility, similarly to the Java compiler's accessor methods. If the field is static, this accessor method is also static. 
Params:
fieldDescription – The field which is to be accessed.
accessType –       The required access type.
Returns:
A setter method for the given field./**
     * Registers a setter for the given {@link FieldDescription} which might
     * itself not be accessible from outside the class. The returned setter method defines the field type as
     * its only argument type, returns {@code void} and is of package-private visibility, similarly to the Java
     * compiler's accessor methods. If the field is {@code static}, this accessor method is also {@code static}.
     *
     * @param fieldDescription The field which is to be accessed.
     * @param accessType       The required access type.
     * @return A setter method for the given field.
     */
    MethodDescription.InDefinedShape registerSetterFor(FieldDescription fieldDescription, AccessType accessType);

    
Indicates the type of access to an accessor method.
/**
     * Indicates the type of access to an accessor method.
     */
    enum AccessType {

        
An access with public visibility. /**
         * An access with {@code public visibility}.
         */
        PUBLIC(Visibility.PUBLIC),

        
An access with default visibility.
/**
         * An access with default visibility.
         */
        DEFAULT(Visibility.PACKAGE_PRIVATE);

        
The implied visibility.
/**
         * The implied visibility.
         */
        private final Visibility visibility;

        
Creates a new access type.
Params:
visibility – The implied visibility./**
         * Creates a new access type.
         *
         * @param visibility The implied visibility.
         */
        AccessType(Visibility visibility) {
            this.visibility = visibility;
        }

        
Returns the implied visibility.
Returns:
The implied visibility./**
         * Returns the implied visibility.
         *
         * @return The implied visibility.
         */
        public Visibility getVisibility() {
            return visibility;
        }
    }

    
A method accessor factory that forbids any accessor registration.
/**
     * A method accessor factory that forbids any accessor registration.
     */
    enum Illegal implements MethodAccessorFactory {

        
The singleton instance.
/**
         * The singleton instance.
         */
        INSTANCE;

        
{@inheritDoc}
/**
         * {@inheritDoc}
         */
        public MethodDescription.InDefinedShape registerAccessorFor(Implementation.SpecialMethodInvocation specialMethodInvocation, AccessType accessType) {
            throw new IllegalStateException("It is illegal to register an accessor for this type");
        }

        
{@inheritDoc}
/**
         * {@inheritDoc}
         */
        public MethodDescription.InDefinedShape registerGetterFor(FieldDescription fieldDescription, AccessType accessType) {
            throw new IllegalStateException("It is illegal to register a field getter for this type");
        }

        
{@inheritDoc}
/**
         * {@inheritDoc}
         */
        public MethodDescription.InDefinedShape registerSetterFor(FieldDescription fieldDescription, AccessType accessType) {
            throw new IllegalStateException("It is illegal to register a field setter for this type");
        }
    }
}