/*
 * 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.facebook.presto.bytecode.debug;

import com.facebook.presto.bytecode.BytecodeNode;
import com.facebook.presto.bytecode.BytecodeVisitor;
import com.facebook.presto.bytecode.MethodGenerationContext;
import com.facebook.presto.bytecode.instruction.LabelNode;
import com.google.common.collect.ImmutableList;
import org.objectweb.asm.MethodVisitor;

import java.util.List;

import static com.google.common.base.MoreObjects.toStringHelper;

public class LineNumberNode
        implements DebugNode
{
    private final int lineNumber;
    private final LabelNode label = new LabelNode();

    public LineNumberNode(int lineNumber)
    {
        this.lineNumber = lineNumber;
    }

    @Override
    public void accept(MethodVisitor visitor, MethodGenerationContext generationContext)
    {
        if (generationContext.updateLineNumber(lineNumber)) {
            label.accept(visitor, generationContext);
            visitor.visitLineNumber(lineNumber, label.getLabel());
        }
    }

    public int getLineNumber()
    {
        return lineNumber;
    }

    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("line", lineNumber)
                .toString();
    }

    @Override
    public List<BytecodeNode> getChildNodes()
    {
        return ImmutableList.of();
    }

    @Override
    public <T> T accept(BytecodeNode parent, BytecodeVisitor<T> visitor)
    {
        return visitor.visitLineNumber(parent, this);
    }
}