/*
 * 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.dynamic.scaffold.subclass;

import net.bytebuddy.ClassFileVersion;
import net.bytebuddy.asm.AsmVisitorWrapper;
import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.DynamicType;
import net.bytebuddy.dynamic.TypeResolutionStrategy;
import net.bytebuddy.dynamic.VisibilityBridgeStrategy;
import net.bytebuddy.dynamic.scaffold.*;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.attribute.AnnotationRetention;
import net.bytebuddy.implementation.attribute.AnnotationValueFilter;
import net.bytebuddy.implementation.attribute.TypeAttributeAppender;
import net.bytebuddy.implementation.auxiliary.AuxiliaryType;
import net.bytebuddy.matcher.ElementMatcher;
import net.bytebuddy.matcher.LatentMatcher;
import net.bytebuddy.pool.TypePool;

import java.util.Collections;
import java.util.List;

import static net.bytebuddy.matcher.ElementMatchers.*;

/**
 * A type builder that creates an instrumented type as a subclass, i.e. a type that is not based on an existing class file.
 *
 * @param <T> A loaded type that the dynamic type is guaranteed to be a subtype of.
 */
@HashCodeAndEqualsPlugin.Enhance
public class SubclassDynamicTypeBuilder<T> extends DynamicType.Builder.AbstractBase.Adapter<T> {

    /**
     * The constructor strategy to apply onto the instrumented type.
     */
    private final ConstructorStrategy constructorStrategy;

    /**
     * Creates a new type builder for creating a subclass.
     *
     * @param instrumentedType             An instrumented type representing the subclass.
     * @param classFileVersion             The class file version to use for types that are not based on an existing class file.
     * @param auxiliaryTypeNamingStrategy  The naming strategy to use for naming auxiliary types.
     * @param annotationValueFilterFactory The annotation value filter factory to use.
     * @param annotationRetention          The annotation retention strategy to use.
     * @param implementationContextFactory The implementation context factory to use.
     * @param methodGraphCompiler          The method graph compiler to use.
     * @param typeValidation               Determines if a type should be explicitly validated.
     * @param visibilityBridgeStrategy     The visibility bridge strategy to apply.
     * @param classWriterStrategy          The class writer strategy to use.
     * @param ignoredMethods               A matcher for identifying methods that should be excluded from instrumentation.
     * @param constructorStrategy          The constructor strategy to apply onto the instrumented type.
     */
    public SubclassDynamicTypeBuilder(InstrumentedType.WithFlexibleName instrumentedType,
                                      ClassFileVersion classFileVersion,
                                      AuxiliaryType.NamingStrategy auxiliaryTypeNamingStrategy,
                                      AnnotationValueFilter.Factory annotationValueFilterFactory,
                                      AnnotationRetention annotationRetention,
                                      Implementation.Context.Factory implementationContextFactory,
                                      MethodGraph.Compiler methodGraphCompiler,
                                      TypeValidation typeValidation,
                                      VisibilityBridgeStrategy visibilityBridgeStrategy,
                                      ClassWriterStrategy classWriterStrategy,
                                      LatentMatcher<? super MethodDescription> ignoredMethods,
                                      ConstructorStrategy constructorStrategy) {
        this(instrumentedType,
                new FieldRegistry.Default(),
                new MethodRegistry.Default(),
                new RecordComponentRegistry.Default(),
                TypeAttributeAppender.ForInstrumentedType.INSTANCE,
                AsmVisitorWrapper.NoOp.INSTANCE,
                classFileVersion,
                auxiliaryTypeNamingStrategy,
                annotationValueFilterFactory,
                annotationRetention,
                implementationContextFactory,
                methodGraphCompiler,
                typeValidation,
                visibilityBridgeStrategy,
                classWriterStrategy,
                ignoredMethods,
                Collections.<DynamicType>emptyList(),
                constructorStrategy);
    }

    /**
     * Creates a new type builder for creating a subclass.
     *
     * @param instrumentedType             An instrumented type representing the subclass.
     * @param fieldRegistry                The field registry to use.
     * @param methodRegistry               The method registry to use.
     * @param recordComponentRegistry      The record component registry to use.
     * @param typeAttributeAppender        The type attribute appender to apply onto the instrumented type.
     * @param asmVisitorWrapper            The ASM visitor wrapper to apply onto the class writer.
     * @param classFileVersion             The class file version to use for types that are not based on an existing class file.
     * @param auxiliaryTypeNamingStrategy  The naming strategy to use for naming auxiliary types.
     * @param annotationValueFilterFactory The annotation value filter factory to use.
     * @param annotationRetention          The annotation retention strategy to use.
     * @param implementationContextFactory The implementation context factory to use.
     * @param methodGraphCompiler          The method graph compiler to use.
     * @param typeValidation               Determines if a type should be explicitly validated.
     * @param visibilityBridgeStrategy     The visibility bridge strategy to apply.
     * @param classWriterStrategy          The class writer strategy to use.
     * @param ignoredMethods               A matcher for identifying methods that should be excluded from instrumentation.
     * @param constructorStrategy          The constructor strategy to apply onto the instrumented type.
     * @param auxiliaryTypes               A list of explicitly required auxiliary types.
     */
    protected SubclassDynamicTypeBuilder(InstrumentedType.WithFlexibleName instrumentedType,
                                         FieldRegistry fieldRegistry,
                                         MethodRegistry methodRegistry,
                                         RecordComponentRegistry recordComponentRegistry,
                                         TypeAttributeAppender typeAttributeAppender,
                                         AsmVisitorWrapper asmVisitorWrapper,
                                         ClassFileVersion classFileVersion,
                                         AuxiliaryType.NamingStrategy auxiliaryTypeNamingStrategy,
                                         AnnotationValueFilter.Factory annotationValueFilterFactory,
                                         AnnotationRetention annotationRetention,
                                         Implementation.Context.Factory implementationContextFactory,
                                         MethodGraph.Compiler methodGraphCompiler,
                                         TypeValidation typeValidation,
                                         VisibilityBridgeStrategy visibilityBridgeStrategy,
                                         ClassWriterStrategy classWriterStrategy,
                                         LatentMatcher<? super MethodDescription> ignoredMethods,
                                         List<? extends DynamicType> auxiliaryTypes,
                                         ConstructorStrategy constructorStrategy) {
        super(instrumentedType,
                fieldRegistry,
                methodRegistry,
                recordComponentRegistry,
                typeAttributeAppender,
                asmVisitorWrapper,
                classFileVersion,
                auxiliaryTypeNamingStrategy,
                annotationValueFilterFactory,
                annotationRetention,
                implementationContextFactory,
                methodGraphCompiler,
                typeValidation,
                visibilityBridgeStrategy,
                classWriterStrategy,
                ignoredMethods,
                auxiliaryTypes);
        this.constructorStrategy = constructorStrategy;
    }

    @Override
    protected DynamicType.Builder<T> materialize(InstrumentedType.WithFlexibleName instrumentedType,
                                                 FieldRegistry fieldRegistry,
                                                 MethodRegistry methodRegistry,
                                                 RecordComponentRegistry recordComponentRegistry,
                                                 TypeAttributeAppender typeAttributeAppender,
                                                 AsmVisitorWrapper asmVisitorWrapper,
                                                 ClassFileVersion classFileVersion,
                                                 AuxiliaryType.NamingStrategy auxiliaryTypeNamingStrategy,
                                                 AnnotationValueFilter.Factory annotationValueFilterFactory,
                                                 AnnotationRetention annotationRetention,
                                                 Implementation.Context.Factory implementationContextFactory,
                                                 MethodGraph.Compiler methodGraphCompiler,
                                                 TypeValidation typeValidation,
                                                 VisibilityBridgeStrategy visibilityBridgeStrategy,
                                                 ClassWriterStrategy classWriterStrategy,
                                                 LatentMatcher<? super MethodDescription> ignoredMethods,
                                                 List<? extends DynamicType> auxiliaryTypes) {
        return new SubclassDynamicTypeBuilder<T>(instrumentedType,
                fieldRegistry,
                methodRegistry,
                recordComponentRegistry,
                typeAttributeAppender,
                asmVisitorWrapper,
                classFileVersion,
                auxiliaryTypeNamingStrategy,
                annotationValueFilterFactory,
                annotationRetention,
                implementationContextFactory,
                methodGraphCompiler,
                typeValidation,
                visibilityBridgeStrategy,
                classWriterStrategy,
                ignoredMethods,
                auxiliaryTypes,
                constructorStrategy);
    }

    /**
     * {@inheritDoc}
     */
    public DynamicType.Unloaded<T> make(TypeResolutionStrategy typeResolutionStrategy) {
        return make(typeResolutionStrategy, TypePool.ClassLoading.ofSystemLoader()); // Mimics the default behavior of ASM for least surprise.
    }

    /**
     * {@inheritDoc}
     */
    public DynamicType.Unloaded<T> make(TypeResolutionStrategy typeResolutionStrategy, TypePool typePool) {
        MethodRegistry.Compiled methodRegistry = constructorStrategy
                .inject(instrumentedType, this.methodRegistry)
                .prepare(applyConstructorStrategy(instrumentedType),
                    methodGraphCompiler,
                    typeValidation,
                    visibilityBridgeStrategy,
                    new InstrumentableMatcher(ignoredMethods))
                .compile(SubclassImplementationTarget.Factory.SUPER_CLASS, classFileVersion);
        return TypeWriter.Default.<T>forCreation(methodRegistry,
                auxiliaryTypes,
                fieldRegistry.compile(methodRegistry.getInstrumentedType()),
                recordComponentRegistry.compile(methodRegistry.getInstrumentedType()),
                typeAttributeAppender,
                asmVisitorWrapper,
                classFileVersion,
                annotationValueFilterFactory,
                annotationRetention,
                auxiliaryTypeNamingStrategy,
                implementationContextFactory,
                typeValidation,
                classWriterStrategy,
                typePool).make(typeResolutionStrategy.resolve());
    }

    /**
     * Applies this builder's constructor strategy to the given instrumented type.
     *
     * @param instrumentedType The instrumented type to apply the constructor onto.
     * @return The instrumented type with the constructor strategy applied onto.
     */
    private InstrumentedType applyConstructorStrategy(InstrumentedType instrumentedType) {
        if (!instrumentedType.isInterface()) {
            for (MethodDescription.Token token : constructorStrategy.extractConstructors(instrumentedType)) {
                instrumentedType = instrumentedType.withMethod(token);
            }
        }
        return instrumentedType;
    }

    /**
     * A matcher that locates all methods that are overridable and not ignored or that are directly defined on the instrumented type.
     */
    @HashCodeAndEqualsPlugin.Enhance
    protected static class InstrumentableMatcher implements LatentMatcher<MethodDescription> {

        /**
         * A matcher for the ignored methods.
         */
        private final LatentMatcher<? super MethodDescription> ignoredMethods;

        /**
         * Creates a latent method matcher that matches all methods that are to be instrumented by a {@link SubclassDynamicTypeBuilder}.
         *
         * @param ignoredMethods A matcher for the ignored methods.
         */
        protected InstrumentableMatcher(LatentMatcher<? super MethodDescription> ignoredMethods) {
            this.ignoredMethods = ignoredMethods;
        }

        /**
         * {@inheritDoc}
         */
        public ElementMatcher<? super MethodDescription> resolve(TypeDescription typeDescription) {
            // Casting is required by JDK 6.
            return (ElementMatcher<? super MethodDescription>) isVirtual().and(not(isFinal()))
                    .and(isVisibleTo(typeDescription))
                    .and(not(ignoredMethods.resolve(typeDescription)))
                    .or(isDeclaredBy(typeDescription));
        }
    }
}