package grpc

import (
	"fmt"
	"net"
	"os"
	"os/signal"

	"github.com/go-logr/logr"

	"edge-infra.dev/pkg/lib/fog"

	syscall "golang.org/x/sys/unix"

	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"

	"edge-infra.dev/pkg/edge/datasync/chirp/persister"
	"edge-infra.dev/pkg/edge/datasync/chirp/server/http"
	"edge-infra.dev/pkg/edge/datasync/internal/config"
	protos "edge-infra.dev/pkg/edge/datasync/internal/protos/upload"
)

type Server struct {
	server *grpc.Server
	logger logr.Logger
	config *config.Config
}

func NewServer(msgPersister persister.MessagePersister, cfg *config.Config) *Server {
	server := grpc.NewServer()

	messagingService := NewMessagingService(msgPersister, cfg)
	protos.RegisterMessagingServiceServer(server, messagingService)

	reflection.Register(server)

	return &Server{server: server, logger: fog.New(), config: cfg}
}

func (s *Server) ListenAndServe() {
	port := s.config.GrpcPort

	lis, err := net.Listen("tcp", fmt.Sprintf(":%s", port))
	if err != nil {
		s.logger.Error(err, "failed to listen on tcp address")
	} else {
		http.SetIsGRPCServerReady(true)
	}

	term := make(chan os.Signal, 1)
	signal.Notify(term, syscall.SIGINT, syscall.SIGTERM)

	go func() {
		<-term
		s.logger.Info("got termination signal. attempting graceful shutdown")
		s.server.GracefulStop()
	}()

	s.logger.Info("starting gRPC server")

	err = s.server.Serve(lis)

	if err != nil {
		s.logger.Error(err, "failed to serve gRPC")
	}

	s.logger.Info("gRPC server shutdown completed")
}