use crate::ir::ir_parameter_or_variable::IrParameterOrVariable;
use crate::ir::ir_variable::IrVrVariableDescriptor;
use crate::ir::register_allocation::VrUser;
use std::collections::HashSet;
use std::fmt::{Display, Formatter};

pub struct IrGetFieldRef {
    self_parameter_or_variable: IrParameterOrVariable,
    field_index: usize,
}

impl IrGetFieldRef {
    pub fn new(self_parameter_or_variable: IrParameterOrVariable, field_index: usize) -> Self {
        Self {
            self_parameter_or_variable,
            field_index,
        }
    }

    pub fn self_parameter_or_variable(&self) -> &IrParameterOrVariable {
        &self.self_parameter_or_variable
    }

    pub fn field_index(&self) -> usize {
        self.field_index
    }
}

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

impl VrUser for IrGetFieldRef {
    fn vr_uses(&self) -> HashSet<IrVrVariableDescriptor> {
        self.self_parameter_or_variable().vr_uses()
    }
}