import { rpc_client } from './rpc_client.jsy'
import { RPC } from './rpc_api.jsy'

export function rpc_plugin(rpc_attr_name='rpc') ::
  let wm = new WeakMap()
  return hub => ::
    hub.rpc_from = rpc_from

    Object.defineProperty @
      hub.router.router_ctx, rpc_attr_name,
      @{} get(...args) ::
        return rpc_from(this.tgt_router)

    return hub[rpc_attr_name] = rpc_from(hub.local)

  function rpc_from(tgt_router) ::
    let rpc = wm.get(tgt_router)
    if undefined === rpc && tgt_router ::
      wm.set @ tgt_router,
        rpc = _rpc_route(tgt_router)
    return rpc

  function _rpc_route(tgt_router) ::
    let client = rpc_client.with @: tgt_router
    let rpc = @{}
      from: rpc_from

      client, to: (...args) => client.to(...args)

      RPC, api(rpc_api, ns) ::
        return Object.assign(this.RPC.create(rpc_api), ns)

      stream(xtgt, rpc_api) ::
        return this.api(rpc_api)
          .rpc_stream(xtgt)

      ep_stateful(...args) ::
        let xrpc = this.api(args.pop())
        return tgt_router.addStream @
          args[0], xtgt => xrpc.rpc_stream(xtgt), args[1]

      ep_idempotent(...args) ::
        let xrpc = this.api(args.pop())
        return tgt_router.addTarget @
          args[0], xrpc.rpc_target(), args[1]

    // aliases
    rpc.endpoint = rpc.ep_stateful

    return tgt_router[rpc_attr_name] = {__proto__: rpc}