/*
 * Copyright 2002-2019 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.springframework.expression.spel.ast;

import org.springframework.asm.MethodVisitor;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.CodeFlow;
import org.springframework.util.Assert;

/**
 * Expression language AST node that represents an integer literal.
 *
 * @author Andy Clement
 * @since 3.0
 */
public class IntLiteral extends Literal {

	private final TypedValue value;


	public IntLiteral(String payload, int startPos, int endPos, int value) {
		super(payload, startPos, endPos);
		this.value = new TypedValue(value);
		this.exitTypeDescriptor = "I";
	}


	@Override
	public TypedValue getLiteralValue() {
		return this.value;
	}

	@Override
	public boolean isCompilable() {
		return true;
	}

	@Override
	public void generateCode(MethodVisitor mv, CodeFlow cf) {
		Integer intValue = (Integer) this.value.getValue();
		Assert.state(intValue != null, "No int value");
		if (intValue == -1) {
			// Not sure we can get here because -1 is OpMinus
			mv.visitInsn(ICONST_M1);
		}
		else if (intValue >= 0 && intValue < 6) {
			mv.visitInsn(ICONST_0 + intValue);
		}
		else {
			mv.visitLdcInsn(intValue);
		}
		cf.pushDescriptor(this.exitTypeDescriptor);
	}

}
