use nom::{
    branch::alt,
    combinator::map,
    multi::{many1, separated_list0},
};

use crate::parser::{
    adt::{state, StateBlock},
    comb::{comb_block, CombBlock},
    declaration,
    proc::ProcBlock,
    tokens::{token, TokenKind as tk, TokenSpan},
    IResult, NetDecl, Span,
};

#[derive(Debug)]
pub enum PortDirection {
    Input,
    Output,
}

#[derive(Debug)]
pub struct PortDecl<'a> {
    pub direction: PortDirection,
    pub net: NetDecl<'a>,
}

#[derive(Debug)]
pub struct Module<'a> {
    pub items: Vec<ModuleItem<'a>>,
}

#[derive(Debug)]
pub enum ModuleItem<'a> {
    Comb(CombBlock<'a>),
    Proc(ProcBlock<'a>),
    State(StateBlock<'a>),
}

fn port_decl(i: TokenSpan) -> IResult<TokenSpan, PortDecl> {
    map(declaration, |net| PortDecl {
        direction: PortDirection::Input,
        net,
    })(i)
}

pub fn inputs_list(input: TokenSpan) -> IResult<TokenSpan, Vec<PortDecl>> {
    separated_list0(token(tk::Comma), port_decl)(input)
}

pub fn module(input: TokenSpan) -> IResult<TokenSpan, Module> {
    map(
        many1(alt((
            map(state, ModuleItem::State),
            map(comb_block, ModuleItem::Comb),
        ))),
        |items| Module { items },
    )(input)
}