package rpc

import (
	"io"

	"git.loafle.net/commons_go/rpc/protocol"
)

type Invoker func(codecReq protocol.ServerCodecRequest) (result interface{}, err error)

func Handle(sh ServerHandler, codec protocol.ServerCodec, r io.Reader, w io.Writer, invoker Invoker) error {
	sh.OnPreRead(r)
	// Create a new codec request.
	codecReq, errNew := codec.NewRequest(r)
	defer func() {
		if nil != codecReq {
			codecReq.Complete()
		}
	}()

	if nil != errNew {
		return errNew
	}
	sh.OnPostRead(r)

	result, err := invoker(codecReq)

	if nil != err {
		sh.OnPreWriteError(w, err)
		codecReq.WriteError(w, 400, err)
		sh.OnPostWriteError(w, err)
	} else {
		sh.OnPreWriteResult(w, result)
		codecReq.WriteResponse(w, result)
		sh.OnPostWriteResult(w, result)
	}

	return nil
}