// This file is part of gnunet-go, a GNUnet-implementation in Golang.
// Copyright (C) 2019-2022 Bernd Fix  >Y<
//
// gnunet-go is free software: you can redistribute it and/or modify it
// under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// gnunet-go is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
// SPDX-License-Identifier: AGPL3.0-or-later

package service

import (
	"context"
	"net/http"
	"time"

	"github.com/bfix/gospel/logger"
	"github.com/gorilla/mux"
	"github.com/gorilla/rpc/v2"
	"github.com/gorilla/rpc/v2/json2"
)

//----------------------------------------------------------------------
//----------------------------------------------------------------------

// JRPCServer for JSON-RPC handling (wrapper to keep type in our package)
type JRPCServer struct {
	*rpc.Server
}

//----------------------------------------------------------------------
// JSON-RPC interface for services to be used as the primary client API
// for perform, manage and monitor GNUnet activities.
//----------------------------------------------------------------------

// RunRPCServer runs the JSON-RPC server. It can be terminated by context only.
func RunRPCServer(ctx context.Context, endpoint string) (srvRPC *JRPCServer, err error) {
	// instantiate RPC service
	srvRPC = &JRPCServer{rpc.NewServer()}
	srvRPC.RegisterCodec(json2.NewCodec(), "application/json")

	// setup RPC request handler
	router := mux.NewRouter()
	router.HandleFunc("/", srvRPC.ServeHTTP)

	// instantiate a server and run it
	srv := &http.Server{
		Handler:           router,
		Addr:              endpoint,
		WriteTimeout:      5 * time.Second,
		ReadTimeout:       15 * time.Second,
		ReadHeaderTimeout: 5 * time.Second,
	}
	// start listening
	go func() {
		if err := srv.ListenAndServe(); err != http.ErrServerClosed {
			logger.Printf(logger.WARN, "[rpc] server listen failed: %s", err.Error())
		}
	}()
	// wait for shutdown
	go func() {
		<-ctx.Done()
		if err := srv.Shutdown(context.Background()); err != nil {
			logger.Printf(logger.WARN, "[rpc] server shutdownn failed: %s", err.Error())
		}
	}()
	return
}