package abstractSyntaxTree.StatementExpression;

import TypeCheck.AbstractType;
import TypeCheck.TypeCheckHelper;
import TypeCheck.TypeCheckResult;
import abstractSyntaxTree.Expression.IExpression;
import abstractSyntaxTree.Expression.InstVarExpression;
import abstractSyntaxTree.Expression.VarRefExpression;
import abstractSyntaxTree.Statement.IStatement;
import org.objectweb.asm.*;

import java.util.Objects;

public class AssignStatementExpression extends AbstractType implements IExpression, IStatement {
    public String operator;
    public IExpression left;
    public IExpression right;

    @Override
    public TypeCheckResult typeCheck() throws Exception {
        TypeCheckHelper helper = new TypeCheckHelper();
        TypeCheckResult result = new TypeCheckResult();

        TypeCheckResult leftType = left.typeCheck();
        TypeCheckResult rightType = right.typeCheck();

        String upperbound = helper.upperBound(leftType.type, rightType.type);
        if (Objects.equals(upperbound, leftType.type)) {
            result.type = leftType.type;
        }
        setTypeCheckResult(result);
        return result;
    }

    @Override
    public void codeGen(MethodVisitor mv) throws Exception {
        left.codeGen(mv);
        right.codeGen(mv);

        if (left instanceof VarRefExpression varRef) {
            //TODO: Implement the handling of a variable reference --> I need a list of local variables
            //      for that to determine if the variable is a local or field variable
        } else if (left instanceof InstVarExpression instVar) {
            mv.visitInsn(Opcodes.DUP_X1);

            // We now again need the owner (class reference), name (of the Field in the owner) and type of the field
            //mv.visitFieldInsn(Opcodes.PUTFIELD, instVar.className, instVar.varName, instVar.type);
        }
    }
}