package main

import (
	"context"
	"flag"
	"fmt"
	"log/slog"
	"net"
	"net/http"
	"os"

	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
	"github.com/tidbcloud/config-center/internal/config"
	"github.com/tidbcloud/config-center/internal/db"
	"github.com/tidbcloud/config-center/internal/grpc_service"
	"github.com/tidbcloud/config-center/internal/middleware"
	cc "github.com/tidbcloud/config-center/proto/config_center"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/grpc/reflection"
)

func main() {
	configPath := flag.String("config", "config.toml", "path to config file")
	grpcPort := flag.Int("grpc-port", 8080, "gRPC server port")
	httpPort := flag.Int("http-port", 8081, "HTTP server port")
	flag.Parse()

	config := config.Init(*configPath)
	configService, err := newConfigCenterService(config)
	if err != nil {
		panic(err)
	}

	// Start gRPC server
	go func() {
		l, err := net.Listen("tcp", fmt.Sprintf(":%d", *grpcPort))
		if err != nil {
			panic(err)
		}

		s := grpc.NewServer(middleware.NewGRPCServerOptions()...)

		cc.RegisterConfigCenterServiceServer(s, configService)
		reflection.Register(s)

		slog.Info("Starting gRPC server", "port", *grpcPort)
		if err := s.Serve(l); err != nil {
			panic(err)
		}
	}()

	// Start HTTP gateway server
	ctx := context.Background()
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	// Register gRPC server endpoint
	mux := runtime.NewServeMux()
	opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}

	err = cc.RegisterConfigCenterServiceHandlerFromEndpoint(ctx, mux, fmt.Sprintf("localhost:%d", *grpcPort), opts)
	if err != nil {
		panic(err)
	}

	// Start HTTP server
	slog.Info("Starting HTTP gateway server", "port", *httpPort)
	if err := http.ListenAndServe(fmt.Sprintf(":%d", *httpPort), mux); err != nil {
		panic(err)
	}
}

func newConfigCenterService(config *config.RootConfig) (*grpc_service.ConfigCenterService, error) {
	logLevel := slog.LevelInfo
	switch config.Log.Level {
	case "debug":
		logLevel = slog.LevelDebug
	case "warn":
		logLevel = slog.LevelWarn
	case "error":
		logLevel = slog.LevelError
	}
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: logLevel}))
	slog.SetDefault(logger)

	db.Migrate(config.Database)
	db.Init(config.Database)
	storage := db.NewRealDB(config.Database)

	if config.ServiceMode == string(grpc_service.ModeRegional) {
		return grpc_service.NewRegionalConfigCenterService(storage, config), nil
	}

	return grpc_service.NewGlobalConfigCenterService(storage)
}