/*
 * Copyright 2013 Guidewire Software, Inc.
 */

package gw.internal.gosu.ir.compiler.bytecode.statement;

import gw.internal.gosu.ir.compiler.bytecode.AbstractBytecodeCompiler;
import gw.internal.gosu.ir.compiler.bytecode.IRBytecodeContext;
import gw.internal.gosu.ir.compiler.bytecode.IRBytecodeCompiler;
import gw.lang.ir.statement.IRDoWhileStatement;
import gw.internal.ext.org.objectweb.asm.Opcodes;
import gw.internal.ext.org.objectweb.asm.Label;
import gw.lang.ir.statement.IRReturnStatement;

public class IRDoWhileStatementCompiler extends AbstractBytecodeCompiler
{
  public static void compile( IRDoWhileStatement doWhileStatement, IRBytecodeContext context )
  {
    Label breakLabel = new Label();
    Label conditionLabel = new Label();
    Label loopBodyStart = new Label();

    context.pushBreakLabel( breakLabel);
    context.pushContinueLabel( conditionLabel );
    context.pushScope();
    try
    {
      if( doWhileStatement.getLeastSignificantTerminalStatement() != null )
      {
        context.visitLabel( conditionLabel );
        IRBytecodeCompiler.compileIRStatement( doWhileStatement.getBody(), context );
        context.visitLabel( breakLabel );
      }
      else
      {
        context.visitLabel( loopBodyStart ); // body start
        IRBytecodeCompiler.compileIRStatement( doWhileStatement.getBody(), context );

        context.visitLabel( conditionLabel );
        context.setLineNumber( doWhileStatement.getLoopTest().getLineNumber() );
        IRBytecodeCompiler.compileIRExpression( doWhileStatement.getLoopTest(), context );
        context.getMv().visitJumpInsn( Opcodes.IFNE, loopBodyStart );

        context.getMv().visitLabel( breakLabel );

        IRReturnStatement implicitReturn = doWhileStatement.getImplicitReturnStatement();
        if( implicitReturn != null )
        {
          IRBytecodeCompiler.compileIRStatement( implicitReturn, context );
        }
      }
    }
    finally
    {
      context.popScope();
      context.popBreakLabel();
      context.popContinueLabel();
    }
  }
}