/*
 * Copyright 2018 the original author or authors.
 *
 * 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 org.gradle.api.internal.tasks.properties.bean;

import com.google.common.annotations.VisibleForTesting;
import org.codehaus.groovy.runtime.ConvertedClosure;
import org.gradle.api.Task;
import org.gradle.api.internal.tasks.properties.PropertyValue;
import org.gradle.api.internal.tasks.properties.PropertyVisitor;
import org.gradle.api.internal.tasks.properties.TypeMetadata;
import org.gradle.internal.reflect.ParameterValidationContext;
import org.gradle.util.ClosureBackedAction;
import org.gradle.util.ConfigureUtil;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
import java.util.Queue;

class NestedRuntimeBeanNode extends AbstractNestedRuntimeBeanNode {
    public NestedRuntimeBeanNode(RuntimeBeanNode<?> parentNode, String propertyName, Object bean, TypeMetadata typeMetadata) {
        super(parentNode, propertyName, bean, typeMetadata);
    }

    @Override
    public void visitNode(PropertyVisitor visitor, Queue<RuntimeBeanNode<?>> queue, RuntimeBeanNodeFactory nodeFactory, ParameterValidationContext validationContext) {
        visitImplementation(visitor);
        visitProperties(visitor, queue, nodeFactory, validationContext);
    }

    private void visitImplementation(PropertyVisitor visitor) {
        visitor.visitInputProperty(getPropertyName(), new ImplementationPropertyValue(getImplementationClass(getBean())), false);
    }

    @VisibleForTesting
    static Class<?> getImplementationClass(Object bean) {
        // When Groovy coerces a Closure into an SAM type, then it creates a Proxy which is backed by the Closure.
        // We want to track the implementation of the Closure, since the class name and classloader of the proxy will not change.
        // Java and Kotlin Lambdas are coerced to SAM types at compile time, so no unpacking is necessary there.
        if (Proxy.isProxyClass(bean.getClass())) {
            InvocationHandler invocationHandler = Proxy.getInvocationHandler(bean);
            if (invocationHandler instanceof ConvertedClosure) {
                Object delegate = ((ConvertedClosure) invocationHandler).getDelegate();
                return delegate.getClass();
            }
            return invocationHandler.getClass();
        }

        // Same as above, if we have wrapped a closure in a WrappedConfigureAction or a ClosureBackedAction, we want to
        // track the closure itself, not the action class.
        if (bean instanceof ConfigureUtil.WrappedConfigureAction) {
            return ((ConfigureUtil.WrappedConfigureAction)bean).getConfigureClosure().getClass();
        }

        if (bean instanceof ClosureBackedAction) {
            return ((ClosureBackedAction)bean).getClosure().getClass();
        }

        return bean.getClass();
    }

    private static class ImplementationPropertyValue implements PropertyValue {

        private final Class<?> beanClass;

        public ImplementationPropertyValue(Class<?> beanClass) {
            this.beanClass = beanClass;
        }

        @Override
        public Object call() {
            return getUnprocessedValue();
        }

        @Override
        public Object getUnprocessedValue() {
            return beanClass;
        }

        @Override
        public void attachProducer(Task producer) {
            // Ignore
        }

        @Override
        public void maybeFinalizeValue() {
            // Ignore
        }
    }
}
