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, Sexp, Atom};

use crate::defs::{BufOps, BufValue};
use crsn::asm::data::Rd;
use crsn::sexp;
use crsn::asm::parse::parse_data::parse_rd;

pub(crate) fn parse<'a>(_pos: &SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
    Ok(ParseRes::ext(match keyword {
        "mkbf" => {
            let dst = args.next_wr()?;
            let len = if args.have_more() {
                args.next_rd()?
            } else {
                Rd::immediate(0)
            };
            BufOps::New { dst, value: BufValue::Zeros(len) }
        }

        "mkbfv" => {
            let dst = args.next_wr()?;

            let next = args.next_or_err()?;

            match next {
                Sexp::Atom(Atom::QS(s), _) => {
                    BufOps::New {
                        dst,
                        value: BufValue::Chars(s),
                    }
                }
                Sexp::List(list, _) => {
                    let mut vals = vec![];
                    for v in list {
                        vals.push(parse_rd(v, args.pcx)?);
                    }
                    BufOps::New {
                        dst,
                        value: BufValue::Values(vals),
                    }
                }
                other => {
                    return Err(CrsnError::Parse("Expected quoted string or a tuple of values".into(), other.pos().clone()));
                }
            }
        }

        "bfrd" => {
            let dst = args.next_wr()?;
            let obj = args.next_rdobj()?;
            let idx = args.next_rd()?;
            BufOps::Read { dst, obj, idx }
        }

        "bfwr" => {
            let obj = args.next_rdobj()?;
            let idx = args.next_rd()?;
            let value = args.next_rd()?;
            BufOps::Write { obj, idx, value }
        }

        "bfsz" => {
            let dst = args.next_wr()?;
            let obj = args.next_rdobj()?;
            BufOps::GetLen { dst, obj }
        }

        "bfins" => {
            let obj = args.next_rdobj()?;
            let idx = args.next_rd()?;
            let value = args.next_rd()?;
            BufOps::Insert { obj, idx, value }
        }

        "bfrm" => {
            let dst = args.next_wr()?;
            let obj = args.next_rdobj()?;
            let idx = args.next_rd()?;
            BufOps::Remove { dst, obj, idx }
        }

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

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

        "bfrpush" => {
            BufOps::Insert {
                obj: args.next_rdobj()?,
                idx: Rd::immediate(0),
                value: args.next_rd()?,
            }
        }

        "bfrpop" => {
            BufOps::Remove {
                dst: args.next_wr()?,
                obj: args.next_rdobj()?,
                idx: Rd::immediate(0),
            }
        }

        "bfrsz" => {
            BufOps::Resize {
                obj: args.next_rdobj()?,
                len: args.next_rd()?,
            }
        }

        "bfrev" => {
            BufOps::Reverse {
                obj: args.next_rdobj()?,
            }
        }

        "bfapp" => {
            BufOps::AppendBuf {
                obj: args.next_rdobj()?,
                obj2: args.next_rdobj()?,
            }
        }

        "bfprep" => {
            BufOps::PrependBuf {
                obj: args.next_rdobj()?,
                obj2: args.next_rdobj()?,
            }
        }

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