use crsn::asm::error::CrsnError;
use crsn::asm::instr::op::OpKind;
use crsn::asm::parse::arg_parser::TokenParser;
use crsn::module::ParseRes;
use crsn::sexp::SourcePosition;

use crate::defs::StackOp;

pub(crate) fn parse<'a>(_pos: &SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
    Ok(ParseRes::ext(match keyword {
        "stack" => {
            StackOp::NewStack {
                dst: args.next_wr()?,
            }
        }

        "push" => {
            StackOp::Push {
                obj: args.next_rdobj()?,
                src: args.next_rd()?,
            }
        }

        "pop" => {
            StackOp::Pop {
                dst: args.next_wr()?,
                obj: args.next_rdobj()?,
            }
        }

        "rpush" => {
            StackOp::ReversePush {
                obj: args.next_rdobj()?,
                src: args.next_rd()?,
            }
        }

        "rpop" => {
            StackOp::ReversePop {
                dst: args.next_wr()?,
                obj: args.next_rdobj()?,
            }
        }

        _other => {
            return Ok(ParseRes::Unknown(args));
        }
    }))
}