/*
 * 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.bytecode.assign.primitive;

import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.type.TypeDefinition;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.StackSize;
import net.bytebuddy.implementation.bytecode.assign.Assigner;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

This delegate is responsible for unboxing a wrapper type to their primitive equivalents.
/**
 * This delegate is responsible for unboxing a wrapper type to their primitive equivalents.
 */
public enum PrimitiveUnboxingDelegate implements StackManipulation {

    
The unboxing delegate for Boolean types. /**
     * The unboxing delegate for {@code Boolean} types.
     */
    BOOLEAN(Boolean.class, boolean.class, StackSize.ZERO, "booleanValue", "()Z"),

    
The unboxing delegate for Byte types. /**
     * The unboxing delegate for {@code Byte} types.
     */
    BYTE(Byte.class, byte.class, StackSize.ZERO, "byteValue", "()B"),

    
The unboxing delegate for Short types. /**
     * The unboxing delegate for {@code Short} types.
     */
    SHORT(Short.class, short.class, StackSize.ZERO, "shortValue", "()S"),

    
The unboxing delegate for Character types. /**
     * The unboxing delegate for {@code Character} types.
     */
    CHARACTER(Character.class, char.class, StackSize.ZERO, "charValue", "()C"),

    
The unboxing delegate for Integer types. /**
     * The unboxing delegate for {@code Integer} types.
     */
    INTEGER(Integer.class, int.class, StackSize.ZERO, "intValue", "()I"),

    
The unboxing delegate for Long types. /**
     * The unboxing delegate for {@code Long} types.
     */
    LONG(Long.class, long.class, StackSize.SINGLE, "longValue", "()J"),

    
The unboxing delegate for Float types. /**
     * The unboxing delegate for {@code Float} types.
     */
    FLOAT(Float.class, float.class, StackSize.ZERO, "floatValue", "()F"),

    
The unboxing delegate for Double types. /**
     * The unboxing delegate for {@code Double} types.
     */
    DOUBLE(Double.class, double.class, StackSize.SINGLE, "doubleValue", "()D");

    
The wrapper type of the represented primitive type.
/**
     * The wrapper type of the represented primitive type.
     */
    private final TypeDescription wrapperType;

    
The represented primitive type.
/**
     * The represented primitive type.
     */
    private final TypeDescription primitiveType;

    
The size increase after a wrapper type was unwrapped.
/**
     * The size increase after a wrapper type was unwrapped.
     */
    private final Size size;

    
The name of the method for unboxing a wrapper value to its primitive value.
/**
     * The name of the method for unboxing a wrapper value to its primitive value.
     */
    private final String unboxingMethodName;

    
The descriptor of the method for unboxing a wrapper value to its primitive value.
/**
     * The descriptor of the method for unboxing a wrapper value to its primitive value.
     */
    private final String unboxingMethodDescriptor;

    
Creates a new primitive unboxing delegate.
Params:
wrapperType –              The wrapper type of the represented primitive type.
primitiveType –            The represented primitive type.
sizeDifference –           The size difference between the wrapper type and its primitive value.
unboxingMethodName –       The name of the method for unboxing a wrapper value to its primitive value.
unboxingMethodDescriptor – The descriptor of the method for unboxing a wrapper value to its primitive value./**
     * Creates a new primitive unboxing delegate.
     *
     * @param wrapperType              The wrapper type of the represented primitive type.
     * @param primitiveType            The represented primitive type.
     * @param sizeDifference           The size difference between the wrapper type and its primitive value.
     * @param unboxingMethodName       The name of the method for unboxing a wrapper value to its primitive value.
     * @param unboxingMethodDescriptor The descriptor of the method for unboxing a wrapper value to its primitive value.
     */
    PrimitiveUnboxingDelegate(Class<?> wrapperType,
                              Class<?> primitiveType,
                              StackSize sizeDifference,
                              String unboxingMethodName,
                              String unboxingMethodDescriptor) {
        this.size = sizeDifference.toIncreasingSize();
        this.wrapperType = TypeDescription.ForLoadedType.of(wrapperType);
        this.primitiveType = TypeDescription.ForLoadedType.of(primitiveType);
        this.unboxingMethodName = unboxingMethodName;
        this.unboxingMethodDescriptor = unboxingMethodDescriptor;
    }

    
Locates a primitive unboxing delegate for a given primitive type.
Params:
typeDefinition – A description of the primitive type.
Returns:
A corresponding primitive unboxing delegate./**
     * Locates a primitive unboxing delegate for a given primitive type.
     *
     * @param typeDefinition A description of the primitive type.
     * @return A corresponding primitive unboxing delegate.
     */
    public static PrimitiveUnboxingDelegate forPrimitive(TypeDefinition typeDefinition) {
        if (typeDefinition.represents(boolean.class)) {
            return BOOLEAN;
        } else if (typeDefinition.represents(byte.class)) {
            return BYTE;
        } else if (typeDefinition.represents(short.class)) {
            return SHORT;
        } else if (typeDefinition.represents(char.class)) {
            return CHARACTER;
        } else if (typeDefinition.represents(int.class)) {
            return INTEGER;
        } else if (typeDefinition.represents(long.class)) {
            return LONG;
        } else if (typeDefinition.represents(float.class)) {
            return FLOAT;
        } else if (typeDefinition.represents(double.class)) {
            return DOUBLE;
        } else {
            throw new IllegalArgumentException("Expected non-void primitive type instead of " + typeDefinition);
        }
    }

    
Creates an unboxing responsible that is capable of unboxing a wrapper type.

If the reference type represents a wrapper type, the wrapper type will simply be unboxed.
If the reference type does not represent a wrapper type, the wrapper type will be inferred by the primitive target type that is later given to the UnboxingResponsible in order to then check if the given type is assignable to the inferred wrapper type.

Params:
typeDefinition – A non-primitive type.
Returns:
An unboxing responsible capable of performing an unboxing operation while considering a further assignment
of the unboxed value./**
     * Creates an unboxing responsible that is capable of unboxing a wrapper type.
     * <ol>
     * <li>If the reference type represents a wrapper type, the wrapper type will simply be unboxed.</li>
     * <li>If the reference type does not represent a wrapper type, the wrapper type will be inferred by the primitive target
     * type that is later given to the
     * {@link net.bytebuddy.implementation.bytecode.assign.primitive.PrimitiveUnboxingDelegate.UnboxingResponsible}
     * in order to then check if the given type is assignable to the inferred wrapper type.</li>
     * </ol>
     *
     * @param typeDefinition A non-primitive type.
     * @return An unboxing responsible capable of performing an unboxing operation while considering a further assignment
     * of the unboxed value.
     */
    public static UnboxingResponsible forReferenceType(TypeDefinition typeDefinition) {
        if (typeDefinition.isPrimitive()) {
            throw new IllegalArgumentException("Expected reference type instead of " + typeDefinition);
        } else if (typeDefinition.represents(Boolean.class)) {
            return ExplicitlyTypedUnboxingResponsible.BOOLEAN;
        } else if (typeDefinition.represents(Byte.class)) {
            return ExplicitlyTypedUnboxingResponsible.BYTE;
        } else if (typeDefinition.represents(Short.class)) {
            return ExplicitlyTypedUnboxingResponsible.SHORT;
        } else if (typeDefinition.represents(Character.class)) {
            return ExplicitlyTypedUnboxingResponsible.CHARACTER;
        } else if (typeDefinition.represents(Integer.class)) {
            return ExplicitlyTypedUnboxingResponsible.INTEGER;
        } else if (typeDefinition.represents(Long.class)) {
            return ExplicitlyTypedUnboxingResponsible.LONG;
        } else if (typeDefinition.represents(Float.class)) {
            return ExplicitlyTypedUnboxingResponsible.FLOAT;
        } else if (typeDefinition.represents(Double.class)) {
            return ExplicitlyTypedUnboxingResponsible.DOUBLE;
        } else {
            return new ImplicitlyTypedUnboxingResponsible(typeDefinition.asGenericType());
        }
    }

    
Returns the wrapper type that this unboxing delegate represents.
Returns:
A generic version of this delegate's wrapper type./**
     * Returns the wrapper type that this unboxing delegate represents.
     *
     * @return A generic version of this delegate's wrapper type.
     */
    protected TypeDescription.Generic getWrapperType() {
        return wrapperType.asGenericType();
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public boolean isValid() {
        return true;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
        methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                wrapperType.asErasure().getInternalName(),
                unboxingMethodName,
                unboxingMethodDescriptor,
                false);
        return size;
    }

    
An explicitly types unboxing responsible is applied for directly unboxing a wrapper type.
/**
     * An explicitly types unboxing responsible is applied for directly unboxing a wrapper type.
     */
    protected enum ExplicitlyTypedUnboxingResponsible implements UnboxingResponsible {

        
An unboxing responsible for unboxing a Boolean type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Boolean} type.
         */
        BOOLEAN(PrimitiveUnboxingDelegate.BOOLEAN),

        
An unboxing responsible for unboxing a Byte type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Byte} type.
         */
        BYTE(PrimitiveUnboxingDelegate.BYTE),

        
An unboxing responsible for unboxing a Short type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Short} type.
         */
        SHORT(PrimitiveUnboxingDelegate.SHORT),

        
An unboxing responsible for unboxing a Character type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Character} type.
         */
        CHARACTER(PrimitiveUnboxingDelegate.CHARACTER),

        
An unboxing responsible for unboxing a Integer type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Integer} type.
         */
        INTEGER(PrimitiveUnboxingDelegate.INTEGER),

        
An unboxing responsible for unboxing a Long type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Long} type.
         */
        LONG(PrimitiveUnboxingDelegate.LONG),

        
An unboxing responsible for unboxing a Float type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Float} type.
         */
        FLOAT(PrimitiveUnboxingDelegate.FLOAT),

        
An unboxing responsible for unboxing a Double type. /**
         * An unboxing responsible for unboxing a {@link java.lang.Double} type.
         */
        DOUBLE(PrimitiveUnboxingDelegate.DOUBLE);

        
The primitive unboxing delegate for handling the given wrapper type.
/**
         * The primitive unboxing delegate for handling the given wrapper type.
         */
        private final PrimitiveUnboxingDelegate primitiveUnboxingDelegate;

        
Creates a new explicitly typed unboxing responsible.
Params:
primitiveUnboxingDelegate – The primitive unboxing delegate for handling the given wrapper type./**
         * Creates a new explicitly typed unboxing responsible.
         *
         * @param primitiveUnboxingDelegate The primitive unboxing delegate for handling the given wrapper type.
         */
        ExplicitlyTypedUnboxingResponsible(PrimitiveUnboxingDelegate primitiveUnboxingDelegate) {
            this.primitiveUnboxingDelegate = primitiveUnboxingDelegate;
        }

        
{@inheritDoc}
/**
         * {@inheritDoc}
         */
        public StackManipulation assignUnboxedTo(TypeDescription.Generic targetType, Assigner assigner, Assigner.Typing typing) {
            return new Compound(
                    primitiveUnboxingDelegate,
                    PrimitiveWideningDelegate.forPrimitive(primitiveUnboxingDelegate.primitiveType).widenTo(targetType));
        }
    }

    
Implementations represent an unboxing delegate that is able to perform the unboxing operation.
/**
     * Implementations represent an unboxing delegate that is able to perform the unboxing operation.
     */
    public interface UnboxingResponsible {

        
Attempts to unbox the represented type in order to assign the unboxed value to the given target type
while using the assigner that is provided by the method call.
Params:
target –   The type that is the desired outcome of the assignment.
assigner – The assigner used to assign the unboxed type to the target type.
typing –   Determines if a type-casting should be attempted for incompatible types.
Returns:
A stack manipulation representing this assignment if such an assignment is possible. An illegal
assignment otherwise./**
         * Attempts to unbox the represented type in order to assign the unboxed value to the given target type
         * while using the assigner that is provided by the method call.
         *
         * @param target   The type that is the desired outcome of the assignment.
         * @param assigner The assigner used to assign the unboxed type to the target type.
         * @param typing   Determines if a type-casting should be attempted for incompatible types.
         * @return A stack manipulation representing this assignment if such an assignment is possible. An illegal
         * assignment otherwise.
         */
        StackManipulation assignUnboxedTo(TypeDescription.Generic target, Assigner assigner, Assigner.Typing typing);
    }

    
An unboxing responsible for an implicitly typed value. This implementation is applied for source types that
were not found to be of a given wrapper type. Instead, this unboxing responsible tries to assign the
source type to the primitive target type's wrapper type before performing an unboxing operation.
/**
     * An unboxing responsible for an implicitly typed value. This implementation is applied for source types that
     * were not found to be of a given wrapper type. Instead, this unboxing responsible tries to assign the
     * source type to the primitive target type's wrapper type before performing an unboxing operation.
     */
    @HashCodeAndEqualsPlugin.Enhance
    protected static class ImplicitlyTypedUnboxingResponsible implements UnboxingResponsible {

        
The original type which should be unboxed but is not of any known wrapper type.
/**
         * The original type which should be unboxed but is not of any known wrapper type.
         */
        private final TypeDescription.Generic originalType;

        
Creates a new implicitly typed unboxing responsible.
Params:
originalType – The original type which should be unboxed but is not of any known wrapper type./**
         * Creates a new implicitly typed unboxing responsible.
         *
         * @param originalType The original type which should be unboxed but is not of any known wrapper type.
         */
        protected ImplicitlyTypedUnboxingResponsible(TypeDescription.Generic originalType) {
            this.originalType = originalType;
        }

        
{@inheritDoc}
/**
         * {@inheritDoc}
         */
        public StackManipulation assignUnboxedTo(TypeDescription.Generic target, Assigner assigner, Assigner.Typing typing) {
            PrimitiveUnboxingDelegate primitiveUnboxingDelegate = PrimitiveUnboxingDelegate.forPrimitive(target);
            return new Compound(
                    assigner.assign(originalType, primitiveUnboxingDelegate.getWrapperType(), typing),
                    primitiveUnboxingDelegate);
        }
    }
}