pub mod eds;
pub use eds::EDSContactResolverBackend;

pub trait ContactResolverBackend {
    type ContactID;

    fn resolve_contact_id(&self, address: &str) -> Option<Self::ContactID>;
    fn get_contact_display_name(&self, contact_id: &Self::ContactID) -> Option<String>;
}

pub type AnyContactID = String;

pub struct ContactResolver<T: ContactResolverBackend> {
    backend: T,
}

impl<T: ContactResolverBackend> ContactResolver<T>
where
    T::ContactID: From<AnyContactID>,
    T::ContactID: Into<AnyContactID>,
    T: Default,
{
    pub fn new(backend: T) -> Self {
        Self { backend }
    }

    pub fn resolve_contact_id(&self, address: &str) -> Option<AnyContactID> {
        self.backend.resolve_contact_id(address).map(|id| id.into())
    }

    pub fn get_contact_display_name(&self, contact_id: &AnyContactID) -> Option<String> {
        let backend_contact_id: T::ContactID = T::ContactID::from((*contact_id).clone());
        self.backend.get_contact_display_name(&backend_contact_id)
    }
}

impl<T: ContactResolverBackend> Default for ContactResolver<T>
where
    T::ContactID: From<AnyContactID>,
    T::ContactID: Into<AnyContactID>,
    T: Default,
{
    fn default() -> Self {
        Self::new(T::default())
    }
}