handler.go

// MIT License
//
// Copyright (c) 2020 Lack
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

package grpc

import (
	"reflect"

	regpb "github.com/lack-io/vine/proto/apis/registry"
	"github.com/lack-io/vine/service/server"
)

type rpcHandler struct {
	name      string
	handler   interface{}
	endpoints []*regpb.Endpoint
	opts      server.HandlerOptions
}

func newRpcHandler(handler interface{}, opts ...server.HandlerOption) server.Handler {
	options := server.HandlerOptions{
		Metadata: make(map[string]map[string]string),
	}

	for _, o := range opts {
		o(&options)
	}

	typ := reflect.TypeOf(handler)
	hdlr := reflect.ValueOf(handler)
	name := reflect.Indirect(hdlr).Type().Name()

	var endpoints []*regpb.Endpoint

	for m := 0; m < typ.NumMethod(); m++ {
		if e := extractEndpoint(typ.Method(m)); e != nil {
			e.Name = name + "." + e.Name

			for k, v := range options.Metadata[e.Name] {
				e.Metadata[k] = v
			}

			endpoints = append(endpoints, e)
		}
	}

	return &rpcHandler{
		name:      name,
		handler:   handler,
		endpoints: endpoints,
		opts:      options,
	}
}

func (r *rpcHandler) Name() string {
	return r.name
}

func (r *rpcHandler) Handler() interface{} {
	return r.handler
}

func (r *rpcHandler) Endpoints() []*regpb.Endpoint {
	return r.endpoints
}

func (r *rpcHandler) Options() server.HandlerOptions {
	return r.opts
}