use crate::ir::ir_variable::{IrVariable, IrVariableDescriptor, IrVrVariableDescriptor};
use crate::ir::register_allocation::{OffsetCounter, VrUser};
use std::cell::RefCell;
use std::collections::{HashMap, HashSet};
use std::fmt::{Display, Formatter};
use std::rc::Rc;

pub struct IrReadField {
    field_ref_variable: Rc<RefCell<IrVariable>>,
}

impl IrReadField {
    pub fn new(field_ref_variable: Rc<RefCell<IrVariable>>) -> Self {
        Self { field_ref_variable }
    }

    pub fn field_ref_variable(&self) -> &Rc<RefCell<IrVariable>> {
        &self.field_ref_variable
    }
}

impl Display for IrReadField {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.field_ref_variable.borrow(),)
    }
}

impl VrUser for IrReadField {
    fn vr_definitions(&self) -> HashSet<IrVrVariableDescriptor> {
        HashSet::new()
    }

    fn vr_uses(&self) -> HashSet<IrVrVariableDescriptor> {
        let mut set = HashSet::new();
        if let IrVariableDescriptor::VirtualRegister(vr_variable) =
            self.field_ref_variable.borrow().descriptor()
        {
            set.insert(vr_variable.clone());
        }
        set
    }

    fn propagate_spills(&mut self, spills: &HashSet<IrVrVariableDescriptor>) {}

    fn propagate_register_assignments(
        &mut self,
        assignments: &HashMap<IrVrVariableDescriptor, usize>,
    ) {
    }

    fn propagate_stack_offsets(&mut self, counter: &mut OffsetCounter) {}
}