use crate::obj::prelude::*;
use std::{any::Any, sync::LazyLock};

pub type IntValue = i64;

static INT_ATTRS: LazyLock<AttrsPtr> = LazyLock::new(|| {
    attrs_ptr! {
        //
        "__str__" => builtin_fun_ptr!("__str__", |_vm, args, _state| {
            if args.len() != 1 {
                todo!("Throw exception: arity error");
            }
            let arg_any = &args[0].as_any();
            let obj = arg_any.downcast_ref::<Int>().expect("Int.__str__ did not receive Int?");

            BuiltinFunResult::Return(Some(ObjPtr::new(Str::new(obj.value().to_string()))))
        }),
    }
});

#[derive(Debug, Clone)]
pub struct Int {
    attrs: AttrsPtr,
    value: IntValue,
}

impl Int {
    pub fn new(value: IntValue) -> Self {
        let attrs = AttrsPtr::clone(&INT_ATTRS);
        // TODO intern
        Int { attrs, value }
    }

    pub fn value(&self) -> IntValue {
        self.value
    }
}

impl Obj for Int {
    fn attrs(&self) -> AttrsPtr {
        AttrsPtr::clone(&self.attrs)
    }

    fn as_any(&self) -> &(dyn Any + 'static) {
        self
    }
}

impl ToString for Int {
    fn to_string(&self) -> String {
        format!("{}", self.value())
    }
}