use std::cell::RefCell;
use std::collections::HashMap;
use std::sync::atomic::AtomicU32;

pub use parse_instr::parse_instructions;

use crate::asm::data::literal::{ConstantName, RegisterAlias, Value};
use crate::asm::data::Register;
use crate::asm::error::CrsnError;
use crate::asm::instr::Op;
use crate::asm::parse::sexp_expect::expect_list;
use crate::module::CrsnExtension;

pub mod parse_cond;
pub mod parse_instr;
pub mod parse_data;
pub mod sexp_expect;
pub mod parse_op;
pub mod arg_parser;
pub mod parse_routine;

pub struct ParserContext<'a> {
    /// Extension modules
    pub parsers: &'a [Box<dyn CrsnExtension>],
    /// Mutable state
    pub state: RefCell<ParserState>,
}

pub struct ParserState {
    /// Register aliases within the routine
    pub reg_aliases: HashMap<RegisterAlias, Register>,

    /// The old reg aliases map is pushed here when entering a routine definition
    pub reg_alias_stack: Vec<HashMap<RegisterAlias, Register>>,

    /// Global constants
    pub constants: HashMap<ConstantName, Value>,
}

pub fn parse(source: &str, parsers: &ParserContext) -> Result<Vec<Op>, CrsnError> {
    let items = expect_list(Some(sexp::parse(source)?), true)?;

    let label_num = AtomicU32::new(0);
    parse_instructions(items.into_iter(), parsers)?
        .flatten(&label_num)
}