use crate::function::FunctionMap;

use super::Value;

fn type_name_of_val<T: ?Sized>(_val: &T) -> &'static str {
    std::any::type_name::<T>()
}

pub trait CustomValue: std::fmt::Debug + BoxClone {
    /// Cursed workaround. Since every type has to implement this
    /// method, we can get a handle back to the type.
    fn as_any(&self) -> &dyn std::any::Any;

    fn value_kind(&self) -> &'static str {
        type_name_of_val(self)
    }

    fn format(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", self)
    }

    fn eq(&self, _: &Value) -> bool {
        false
    }

    fn partial_cmp(&self, _: &Value) -> Option<std::cmp::Ordering> {
        None
    }

    fn functions(&self) -> Option<FunctionMap> {
        None
    }

    fn to_bool(&self) -> bool {
        true
    }

    fn add(&self, _: &Value) -> Value {
        Value::default()
    }

    fn sub(&self, _: &Value) -> Value {
        Value::default()
    }

    fn mul(&self, _: &Value) -> Value {
        Value::default()
    }

    fn div(&self, _: &Value) -> Value {
        Value::default()
    }

    fn rem(&self, _: &Value) -> Value {
        Value::default()
    }

}

impl PartialEq<Value> for dyn CustomValue {
    fn eq(&self, other: &Value) -> bool {
        self.eq(other)
    }
}

impl PartialOrd<Value> for dyn CustomValue {
    fn partial_cmp(&self, other: &Value) -> Option<std::cmp::Ordering> {
        self.partial_cmp(other)
    }
}

pub trait BoxClone {
    fn clone_box(&self) -> Box<dyn CustomValue>;
}

impl<T> BoxClone for T
where
    T: 'static + CustomValue + Clone,
{
    fn clone_box(&self) -> Box<dyn CustomValue> {
        Box::new(self.clone())
    }
}

impl Clone for Box<dyn CustomValue> {
    fn clone(&self) -> Self {
        self.clone_box()
    }
}