pub mod export_import;
pub mod handle;
pub mod id;
mod null;
pub mod serde_support;

use crate::forwarder::ServiceObjectId;
use crate::port::Port;
use std::sync::Weak;

pub use handle::Handle;
pub use null::{create_null_service, NullService};
pub type MethodId = u32;

/// Exporter sides's interface to the service object. This will be implemented
/// by each service trait's unique wrapper in the macro
pub trait Dispatch: Send + Sync {
    fn dispatch_and_call(&self, method: MethodId, args: &[u8]) -> Vec<u8>;
}

impl<F> Dispatch for F
where
    F: Fn(MethodId, &[u8]) -> Vec<u8> + Send + Sync,
{
    fn dispatch_and_call(&self, method: MethodId, args: &[u8]) -> Vec<u8> {
        self(method, args)
    }
}

/// The `Service` trait is a marker that is used as a supertrait for a service trait,
/// indicating that the trait is for a service.
///
/// It is bound to `Send` and `Sync`, and that's all.
/// Please put this as a supertrait for every service trait, and implement it
/// for all concrete service implementers.
///
/**
## Example
```
use remote_trait_object::*;

#[service]
pub trait Piano: Service {
    fn play(&mut self);
}

struct Steinway;
impl Service for Steinway {}
impl Piano for Steinway {
    fn play(&mut self) {
        println!("Do Re Mi");
    }
}
```
**/
pub trait Service: Send + Sync {}

/// A serde de/serialization format that will be used for a service.
pub trait SerdeFormat {
    fn to_vec<S: serde::Serialize>(s: &S) -> Result<Vec<u8>, ()>;
    fn from_slice<D: serde::de::DeserializeOwned>(data: &[u8]) -> Result<D, ()>;
}

/// In most case the format isn't important because the users won't see the raw data directly anyway.
/// Thus we provide a default format for the macro.
pub struct Cbor;

impl SerdeFormat for Cbor {
    fn to_vec<S: serde::Serialize>(s: &S) -> Result<Vec<u8>, ()> {
        serde_cbor::to_vec(s).map_err(|_| ())
    }

    fn from_slice<D: serde::de::DeserializeOwned>(data: &[u8]) -> Result<D, ()> {
        serde_cbor::from_slice(data).map_err(|_| ())
    }
}