package abstractSyntaxTree.Expression;

import TypeCheck.AbstractType;
import TypeCheck.TypeCheckHelper;
import TypeCheck.TypeCheckResult;
import abstractSyntaxTree.Datatype.IDatatype;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

import java.util.Objects;

public class UnaryExpression extends AbstractType implements IExpression{
    public String operator;
    public IDatatype operand;
    @Override
    public TypeCheckResult typeCheck() throws Exception {
        TypeCheckResult result = new TypeCheckResult();

        TypeCheckResult operandTypeCheckResult = operand.typeCheck();
        String operandType = operandTypeCheckResult.type;

        switch (operator) {

            case "!" :{
                if (Objects.equals(operandType, "bool")){
                    result.type = "bool";
                }
                break;
            }

            case "-":
            case "+":
                if (Objects.equals(operandType, "int")){
                    result.type = "int";
                }
                break;

        }

        setTypeCheckResult(result);
        return result;
    }

    @Override
    public void codeGen(MethodVisitor mv) throws Exception {

        operand.codeGen(mv);

        switch (operator) {
            case "!":
                //XOR with 1 to get the negation
                mv.visitInsn(Opcodes.ICONST_1);
                mv.visitInsn(Opcodes.IXOR);
                break;
            case "-":
                mv.visitInsn(Opcodes.INEG);
                break;
            case "+":
                break;

            default: throw new Exception("Unknown operator :" + operator);
        }

    }
}