use crate::frontend::{CallArgument, Callable, Type};
use crate::rtlil;
use crate::rtlil::SigSpec;

fn instantiate_unop(celltype: &str, id: &str, args: &[SigSpec], ret: &SigSpec) -> rtlil::Cell {
    let a = args
        .get(0)
        .expect("wrong argcount slipped through type check");
    assert_eq!(args.len(), 1);

    let mut cell = rtlil::Cell::new(id, celltype);
    cell.add_param("\\A_SIGNED", "0");
    cell.add_param("\\A_WIDTH", "1");
    cell.add_param("\\Y_WIDTH", "1");
    cell.add_connection("\\A", a);
    cell.add_connection("\\Y", ret);
    cell
}

fn instantiate_binop(celltype: &str, id: &str, args: &[SigSpec], ret: &SigSpec) -> rtlil::Cell {
    let a = args
        .get(0)
        .expect("wrong argcount slipped through type check");
    let b = args
        .get(1)
        .expect("wrong argcount slipped through type check");
    assert_eq!(args.len(), 2);

    let mut cell = rtlil::Cell::new(id, celltype);
    cell.add_param("\\A_SIGNED", "0");
    cell.add_param("\\A_WIDTH", "1");
    cell.add_param("\\B_SIGNED", "0");
    cell.add_param("\\B_WIDTH", "1");
    cell.add_param("\\Y_WIDTH", "1");
    cell.add_connection("\\A", a);
    cell.add_connection("\\B", b);
    cell.add_connection("\\Y", ret);
    cell
}

fn make_binop_callable(name: &str, celltype: &'static str) -> Callable {
    let args = vec![
        CallArgument {
            name: "A".to_owned(),
            atype: Type::wire(),
        },
        CallArgument {
            name: "B".to_owned(),
            atype: Type::wire(),
        },
    ];
    Callable {
        name: name.to_owned(),
        args,
        ret: Type::wire(),
        instantiate: Box::new(move |id, args, ret| instantiate_binop(celltype, id, args, ret)),
    }
}

fn make_unnop_callable(name: &str, celltype: &'static str) -> Callable {
    let args = vec![CallArgument {
        name: "A".to_owned(),
        atype: Type::wire(),
    }];
    Callable {
        name: name.to_owned(),
        args,
        ret: Type::wire(),
        instantiate: Box::new(move |id, args, ret| instantiate_unop(celltype, id, args, ret)),
    }
}

pub fn get_builtins() -> Vec<Callable> {
    vec![
        make_binop_callable("and", "$and"),
        make_binop_callable("or", "$or"),
        make_binop_callable("xor", "$xor"),
        make_binop_callable("xnor", "$xnor"),
        make_unnop_callable("not", "$not"),
    ]
}