Permify / permify

package servers

import (

	"context"

	"errors"

	"fmt"

	"log/slog"

	"net"

	"net/http"

	"net/http/pprof"

	"time"

	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/logging"

	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/ratelimit"

	grpcAuth "github.com/grpc-ecosystem/go-grpc-middleware/auth"

	grpcRecovery "github.com/grpc-ecosystem/go-grpc-middleware/recovery"

	grpcValidator "github.com/grpc-ecosystem/go-grpc-middleware/validator"

	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"

	"github.com/rs/cors"

	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"

	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp" // HTTP telemetry

	"google.golang.org/grpc"

	"google.golang.org/grpc/credentials"

	"google.golang.org/grpc/credentials/insecure"

	"google.golang.org/grpc/reflection"

	"google.golang.org/protobuf/encoding/protojson"

	health "google.golang.org/grpc/health/grpc_health_v1" // gRPC health check

	oidc "github.com/Permify/permify/internal/authn/openid"

	"github.com/Permify/permify/internal/authn/preshared"

	"github.com/Permify/permify/internal/config"

	"github.com/Permify/permify/internal/invoke"

	"github.com/Permify/permify/internal/middleware"

	"github.com/Permify/permify/internal/storage"

	grpcV1 "github.com/Permify/permify/pkg/pb/base/v1"

)

// Container is a struct that holds the invoker and various storage

// for permission-related operations. It serves as a central point of access

// for interacting with the underlying data and services.

type Container struct {

	// Invoker for performing permission-related operations

	Invoker invoke.Invoker

	// DataReader for reading data from storage

	DR storage.DataReader

	// DataWriter for writing data to storage

	DW storage.DataWriter

	// BundleReader for reading bundle from storage

	BR storage.BundleReader

	// BundleWriter for writing bundle to storage

	BW storage.BundleWriter

	// SchemaReader for reading schemas from storage

	SR storage.SchemaReader

	// SchemaWriter for writing schemas to storage

	SW storage.SchemaWriter

	// TenantReader for reading tenant information from storage

	TR storage.TenantReader

	// TenantWriter for writing tenant information to storage

	TW storage.TenantWriter

	W storage.Watcher

}

// NewContainer is a constructor for the Container struct.

// It takes an Invoker, RelationshipReader, RelationshipWriter, SchemaReader, SchemaWriter,

// TenantReader, and TenantWriter as arguments, and returns a pointer to a Container instance.

func NewContainer(

	invoker invoke.Invoker,

	dr storage.DataReader,

	dw storage.DataWriter,

	br storage.BundleReader,

	bw storage.BundleWriter,

	sr storage.SchemaReader,

	sw storage.SchemaWriter,

	tr storage.TenantReader,

	tw storage.TenantWriter,

	w storage.Watcher,

) *Container {

	return &Container{

		Invoker: invoker,

		DR:      dr,

		DW:      dw,

		BR:      br,

		BW:      bw,

		SR:      sr,

		SW:      sw,

		TR:      tr,

		TW:      tw,

		W:       w,

	}

}

// Run is a method that starts the Container and its services, including the gRPC server,

// an optional HTTP server, and an optional profiler server. It also sets up authentication,

// TLS configurations, and interceptors as needed.

func (s *Container) Run(

	ctx context.Context,

	srv *config.Server,

	logger *slog.Logger,

	dst *config.Distributed,

	authentication *config.Authn,

	profiler *config.Profiler,

	localInvoker invoke.Invoker,

) error {

	var err error

	limiter := middleware.NewRateLimiter(srv.RateLimit) // for example 1000 req/sec

	lopts := []logging.Option{

		logging.WithLogOnEvents(logging.StartCall, logging.FinishCall),

	}

	unaryInterceptors := []grpc.UnaryServerInterceptor{

		grpcValidator.UnaryServerInterceptor(),

		grpcRecovery.UnaryServerInterceptor(),

		ratelimit.UnaryServerInterceptor(limiter),

		logging.UnaryServerInterceptor(InterceptorLogger(logger), lopts...),

	}

	streamingInterceptors := []grpc.StreamServerInterceptor{

		grpcValidator.StreamServerInterceptor(),

		grpcRecovery.StreamServerInterceptor(),

		ratelimit.StreamServerInterceptor(limiter),

		logging.StreamServerInterceptor(InterceptorLogger(logger), lopts...),

	}

	// Configure authentication based on the provided method ("preshared" or "oidc").

	// Add the appropriate interceptors to the unary and streaming interceptors.

	if authentication != nil && authentication.Enabled {

		switch authentication.Method {

		case "preshared":

			var authenticator *preshared.KeyAuthn

			authenticator, err = preshared.NewKeyAuthn(ctx, authentication.Preshared)

			if err != nil {

				return err

			}

			unaryInterceptors = append(unaryInterceptors, grpcAuth.UnaryServerInterceptor(middleware.AuthFunc(authenticator)))

			streamingInterceptors = append(streamingInterceptors, grpcAuth.StreamServerInterceptor(middleware.AuthFunc(authenticator)))

		case "oidc": // OpenID Connect authentication

			var authenticator *oidc.Authn                                    // OIDC authenticator

			authenticator, err = oidc.NewOidcAuthn(ctx, authentication.Oidc) // Create OIDC authenticator

			if err != nil {                                                  // Check for errors

				return err // Return error

			} // OIDC authenticator created

			unaryInterceptors = append(unaryInterceptors, grpcAuth.UnaryServerInterceptor(middleware.AuthFunc(authenticator)))

			streamingInterceptors = append(streamingInterceptors, grpcAuth.StreamServerInterceptor(middleware.AuthFunc(authenticator)))

		default: // Unknown authentication method

			return fmt.Errorf("unknown authentication method: '%s'", authentication.Method) // Return error

		}

	}

	opts := []grpc.ServerOption{

		grpc.ChainUnaryInterceptor(unaryInterceptors...),

		grpc.ChainStreamInterceptor(streamingInterceptors...),

		grpc.StatsHandler(otelgrpc.NewServerHandler()),

	}

	if srv.GRPC.TLSConfig.Enabled {

		var c credentials.TransportCredentials

		c, err = credentials.NewServerTLSFromFile(srv.GRPC.TLSConfig.CertPath, srv.GRPC.TLSConfig.KeyPath)

		if err != nil {

			return err

		}

		opts = append(opts, grpc.Creds(c))

	}

	// Create a new gRPC server instance with the provided options.

	grpcServer := grpc.NewServer(opts...)

	// Register various gRPC services to the server.

	grpcV1.RegisterPermissionServer(grpcServer, NewPermissionServer(s.Invoker))

	grpcV1.RegisterSchemaServer(grpcServer, NewSchemaServer(s.SW, s.SR))

	grpcV1.RegisterDataServer(grpcServer, NewDataServer(s.DR, s.DW, s.BR, s.SR))

	grpcV1.RegisterBundleServer(grpcServer, NewBundleServer(s.BR, s.BW))

	grpcV1.RegisterTenancyServer(grpcServer, NewTenancyServer(s.TR, s.TW))

	grpcV1.RegisterWatchServer(grpcServer, NewWatchServer(s.W, s.DR))

	// Register health check and reflection services for gRPC.

	health.RegisterHealthServer(grpcServer, NewHealthServer()) // Register health server

	reflection.Register(grpcServer)

	// Create another gRPC server, presumably for invoking permissions.

	invokeServer := grpc.NewServer(opts...)

	grpcV1.RegisterPermissionServer(invokeServer, NewPermissionServer(localInvoker))

	// Register health check and reflection services for the invokeServer.

	health.RegisterHealthServer(invokeServer, NewHealthServer()) // Register health server for invoker

	reflection.Register(invokeServer)

	// If profiling is enabled, set up the profiler using the net/http package.

	if profiler.Enabled {

		// Create a new HTTP ServeMux to register pprof routes.

		mux := http.NewServeMux()

		mux.HandleFunc("/debug/pprof/", pprof.Index)

		mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)

		mux.HandleFunc("/debug/pprof/profile", pprof.Profile)

		mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)

		mux.HandleFunc("/debug/pprof/trace", pprof.Trace)

		// Run the profiler server in a separate goroutine.

		go func() {

			// Log a message indicating the profiler server's start status and port.

			slog.Info(fmt.Sprintf("🚀 profiler server successfully started: %s", profiler.Port))

			// Define the HTTP server with timeouts and the mux handler for pprof routes.

			pprofserver := &http.Server{

				Addr:         ":" + profiler.Port,

				Handler:      mux,

				ReadTimeout:  20 * time.Second,

				WriteTimeout: 20 * time.Second,

				IdleTimeout:  15 * time.Second,

			}

			// Start the profiler server.

			if err := pprofserver.ListenAndServe(); err != nil {

				// Check if the error was due to the server being closed, and log it.

				if errors.Is(err, http.ErrServerClosed) { // Server closed error

					slog.Error("failed to start profiler", slog.Any("error", err)) // Log profiler error

				}

			}

		}()

	}

	var lis net.Listener

	lis, err = net.Listen("tcp", ":"+srv.GRPC.Port)

	if err != nil {

		return err

	}

	var invokeLis net.Listener

	invokeLis, err = net.Listen("tcp", ":"+dst.Port)

	if err != nil {

		return err

	}

	// Start the gRPC server.

	go func() {

		if err := grpcServer.Serve(lis); err != nil { // gRPC server error

			slog.Error("failed to start grpc server", slog.Any("error", err)) // Log gRPC error

		}

	}()

	go func() {

		if err := invokeServer.Serve(invokeLis); err != nil { // Invoker server error

			slog.Error("failed to start invoke grpc server", slog.Any("error", err)) // Log invoker error

		}

	}()

	slog.Info(fmt.Sprintf("🚀 grpc server successfully started: %s", srv.GRPC.Port))

	slog.Info(fmt.Sprintf("🚀 invoker grpc server successfully started: %s", dst.Port))

	var httpServer *http.Server

	// Start the optional HTTP server with CORS and optional TLS configurations.

	// Connect to the gRPC server and register the HTTP handlers for each service.

	if srv.HTTP.Enabled {

		options := []grpc.DialOption{

			grpc.WithBlock(),

		}

		if srv.GRPC.TLSConfig.Enabled {

			c, err := credentials.NewClientTLSFromFile(srv.GRPC.TLSConfig.CertPath, srv.NameOverride)

			if err != nil {

				return err

			}

			options = append(options, grpc.WithTransportCredentials(c))

		} else {

			options = append(options, grpc.WithTransportCredentials(insecure.NewCredentials()))

		}

		timeoutCtx, cancel := context.WithTimeout(ctx, 3*time.Second)

		defer cancel()

		conn, err := grpc.DialContext(timeoutCtx, ":"+srv.GRPC.Port, options...)

		if err != nil {

			return err

		}

		defer func() {

			if err = conn.Close(); err != nil { // Connection close error

				slog.Error("Failed to close gRPC connection", slog.Any("error", err)) // Log close error

			}

		}()

		healthClient := health.NewHealthClient(conn) // Create health client

		muxOpts := []runtime.ServeMuxOption{

			runtime.WithHealthzEndpoint(healthClient), // Add health endpoint

			runtime.WithMarshalerOption(runtime.MIMEWildcard, &runtime.HTTPBodyMarshaler{

				Marshaler: &runtime.JSONPb{

					MarshalOptions: protojson.MarshalOptions{

						UseProtoNames:   true,

						EmitUnpopulated: true,

					},

					UnmarshalOptions: protojson.UnmarshalOptions{

						DiscardUnknown: true,

					},

				},

			}),

			runtime.WithMiddlewares(func(next runtime.HandlerFunc) runtime.HandlerFunc { // OpenTelemetry middleware

				type key struct{} // Context key type

				otelHandler := otelhttp.NewHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { // HTTP handler with telemetry

					pathParams := r.Context().Value(key{}).(map[string]string) // Get path params

					next(w, r, pathParams)                                     // Call next handler

				}), "server", // Server name

					otelhttp.WithServerName("permify"),                // Set server name

					otelhttp.WithSpanNameFormatter(httpNameFormatter), // Format span name

				) // OpenTelemetry handler created

				return func(w http.ResponseWriter, r *http.Request, pathParams map[string]string) { // Middleware handler

					r = r.WithContext(context.WithValue(r.Context(), key{}, pathParams)) // Add path params to context

					otelHandler.ServeHTTP(w, r)                                          // Serve with telemetry

				} // Return middleware handler

			}), // Middleware registered

		}

		mux := runtime.NewServeMux(muxOpts...)

		if err = grpcV1.RegisterPermissionHandler(ctx, mux, conn); err != nil {

			return err

		}

		if err = grpcV1.RegisterSchemaHandler(ctx, mux, conn); err != nil {

			return err

		}

		if err = grpcV1.RegisterDataHandler(ctx, mux, conn); err != nil {

			return err

		}

		if err = grpcV1.RegisterBundleHandler(ctx, mux, conn); err != nil {

			return err

		}

		if err = grpcV1.RegisterTenancyHandler(ctx, mux, conn); err != nil {

			return err

		}

		corsHandler := cors.New(cors.Options{ // CORS configuration

			AllowCredentials: true,                        // Allow credentials

			AllowedOrigins:   srv.HTTP.CORSAllowedOrigins, // Allowed origins

			AllowedHeaders:   srv.HTTP.CORSAllowedHeaders, // Allowed headers

			AllowedMethods: []string{ // Allowed HTTP methods

				http.MethodGet, http.MethodPost, // GET and POST

				http.MethodHead, http.MethodPatch, http.MethodDelete, http.MethodPut, // Other methods

			}, // Methods configured

		}).Handler(mux) // CORS handler created

		httpServer = &http.Server{ // HTTP server configuration

			Addr:              ":" + srv.HTTP.Port, // Server address

			Handler:           corsHandler,         // CORS handler

			ReadHeaderTimeout: 5 * time.Second,

		}

		// Start the HTTP server with TLS if enabled, otherwise without TLS.

		go func() {

			var err error

			if srv.HTTP.TLSConfig.Enabled {

				err = httpServer.ListenAndServeTLS(srv.HTTP.TLSConfig.CertPath, srv.HTTP.TLSConfig.KeyPath)

			} else {

				err = httpServer.ListenAndServe()

			}

			if !errors.Is(err, http.ErrServerClosed) {

				slog.Error(err.Error())

			}

		}()

		slog.Info(fmt.Sprintf("🚀 http server successfully started: %s", srv.HTTP.Port))

	}

	// Wait for the context to be canceled (e.g., due to a signal).

	<-ctx.Done()

	// Shutdown the servers gracefully.

	ctxShutdown, cancel := context.WithTimeout(ctx, 5*time.Second)

	defer cancel()

	if httpServer != nil {

		if err := httpServer.Shutdown(ctxShutdown); err != nil {

			slog.Error(err.Error())

			return err

		}

	}

	// Gracefully stop the gRPC server.

	grpcServer.GracefulStop()

	// Gracefully stop the invoke server.

	invokeServer.GracefulStop()

	slog.Info("gracefully shutting down")

	return nil

}

// InterceptorLogger adapts slog logger to interceptor logger.

func InterceptorLogger(l *slog.Logger) logging.Logger {

	return logging.LoggerFunc(func(ctx context.Context, lvl logging.Level, msg string, fields ...any) {

		l.Log(ctx, slog.Level(lvl), msg, fields...)

	})

} // End of InterceptorLogger

func httpNameFormatter(_ string, req *http.Request) string { // Format HTTP span name

	pp, ok := runtime.HTTPPattern(req.Context()) // Get HTTP pattern

	path := "<not found>"                        // Default path

	if ok {                                      // Pattern found

		path = pp.String() // Get path string

	} // Path determined

	return req.Method + " " + path // Return formatted name

} // End of httpNameFormatter