/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * 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 com.android.build.gradle.shrinker;

import com.android.annotations.NonNull;
import com.android.annotations.Nullable;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

import java.io.File;

/**
 * {@link ClassVisitor} that adds visited classes, methods and fields to a {@link ShrinkerGraph}.
 */
public class ClassStructureVisitor<T> extends ClassVisitor {

    @Nullable
    private final File mClassFile;
    private final ShrinkerGraph<T> mGraph;

    private T mClass;

    public ClassStructureVisitor(
            @NonNull ShrinkerGraph<T> graph,
            @Nullable File classFile,
            @Nullable ClassVisitor cv) {
        super(Opcodes.ASM5, cv);
        mClassFile = classFile;
        mGraph = graph;
    }

    @Override
    public void visit(int version, int access, String name, String signature, String superName,
            String[] interfaces) {
        mClass = mGraph.addClass(name, superName, interfaces, access, mClassFile);
        super.visit(version, access, name, signature, superName, interfaces);
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc, String signature,
            String[] exceptions) {
        final T method = mGraph.addMember(mClass, name, desc, access);

        MethodVisitor superVisitor = super.visitMethod(access, name, desc, signature, exceptions);
        return new MethodVisitor(Opcodes.ASM5, superVisitor) {
            @Override
            public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                mGraph.addAnnotation(method, Type.getType(desc).getInternalName());
                return super.visitAnnotation(desc, visible);
            }
        };
    }

    @Override
    public FieldVisitor visitField(int access, String name, String desc, String signature,
            Object value) {
        final T field = mGraph.addMember(mClass, name, desc, access);

        FieldVisitor superVisitor = super.visitField(access, name, desc, signature, value);
        return new FieldVisitor(Opcodes.ASM5, superVisitor) {
            @Override
            public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                mGraph.addAnnotation(field, Type.getType(desc).getInternalName());
                return super.visitAnnotation(desc, visible);
            }
        };
    }

    @Override
    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
        mGraph.addAnnotation(mClass, Type.getType(desc).getInternalName());
        return super.visitAnnotation(desc, visible);
    }
}
