/*
 * Copyright 2014 NAVER Corp.
 *
 * 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.navercorp.pinpoint.test.util;

import com.navercorp.pinpoint.common.util.IOUtils;
import com.navercorp.pinpoint.profiler.util.JavaAssistUtils;

import java.io.IOException;
import java.io.InputStream;

// TODO move package
public final class BytecodeUtils {

    private BytecodeUtils() {
    }


    public static byte[] getClassFile(ClassLoader classLoader, String className) {
        if (className == null) {
            throw new NullPointerException("className");
        }
        classLoader = getClassLoader(classLoader);

        final String classInternalName = JavaAssistUtils.javaClassNameToJvmResourceName(className);
        final InputStream is = classLoader.getResourceAsStream(classInternalName);
        if (is == null) {
            throw new RuntimeException("No such class file: " + className);
        }

        try {
            return IOUtils.toByteArray(is);
        } catch (IOException e) {
            throw new RuntimeException("class read fail file: " + className, e);
        }
    }

    private static ClassLoader getClassLoader(ClassLoader classLoader) {
        if (classLoader == null) {
            return ClassLoader.getSystemClassLoader();
        }
        return classLoader;
    }
}
