use super::frame;
use super::ir;
use super::temp;

#[derive(Debug)]
pub enum Expression {
    Exp(ir::Expression),
    Void(ir::Statement),
}

pub struct Translate<F> {
    level_counter: usize,
    _frametype: ::std::marker::PhantomData<F>,
}

pub enum Level<'a, F>
    where F: 'a + frame::Frame {
    Top,
    Level {
        parent: &'a Level<'a, F>,
        frame: F,
        unique_id: usize,
    },
}

impl<F: frame::Frame> Translate<F> {
    pub fn new() -> Translate<F> {
        Translate {
            level_counter: 0,
            _frametype: ::std::marker::PhantomData,
        }
    }

    pub fn make_level<'a>(
        &mut self,
        parent: &'a Level<F>,
        name: temp::TempLabel,
        formals: Vec<frame::Escape>) -> Level<'a, F> {
        let id = self.level_counter;
        self.level_counter += 1;
        Level::Level {
            parent: parent,
            frame: F::new(name, formals),
            unique_id: id,
        }
    }

    pub fn make_num(&mut self, num: u64) -> Expression {
        Expression::Exp(ir::Expression::Const(num))
    }
}