Add authentication server, dev CLI, Docker multi-service setup, and cross-platform improvements

server/internal/interceptor/diff.go

@@ -0,0 +1,130 @@
+package interceptor
+
+import (
+	"context"
+	"log"
+	"reflect"
+	"sort"
+	"strings"
+	"sync"
+
+	pb "lunar-tear/server/gen/proto"
+	"lunar-tear/server/internal/service"
+	"lunar-tear/server/internal/store"
+	"lunar-tear/server/internal/userdata"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+type diffUserDataGetter interface {
+	GetDiffUserData() map[string]*pb.DiffData
+}
+
+var (
+	diffFieldCache sync.Map // map[reflect.Type]bool
+	diffDataMapTyp = reflect.TypeFor[map[string]*pb.DiffData]()
+)
+
+func hasDiffField(resp any) bool {
+	t := reflect.TypeOf(resp)
+	if cached, ok := diffFieldCache.Load(t); ok {
+		return cached.(bool)
+	}
+	elem := t
+	if elem.Kind() == reflect.Pointer {
+		elem = elem.Elem()
+	}
+	f, ok := elem.FieldByName("DiffUserData")
+	result := ok && f.Type == diffDataMapTyp
+	diffFieldCache.Store(t, result)
+	return result
+}
+
+func NewDiffInterceptor(
+	users store.UserRepository,
+	sessions store.SessionRepository,
+) grpc.UnaryServerInterceptor {
+	return func(
+		ctx context.Context,
+		req any,
+		info *grpc.UnaryServerInfo,
+		handler grpc.UnaryHandler,
+	) (any, error) {
+		if skipDiffForMethod(info.FullMethod) {
+			return handler(ctx, req)
+		}
+
+		userId := service.CurrentUserId(ctx, users, sessions)
+		if userId == 0 {
+			return handler(ctx, req)
+		}
+
+		before, err := users.LoadUser(userId)
+		if err != nil {
+			return handler(ctx, req)
+		}
+
+		resp, handlerErr := handler(ctx, req)
+		if handlerErr != nil || resp == nil {
+			return resp, handlerErr
+		}
+
+		if !hasDiffField(resp) {
+			return resp, nil
+		}
+
+		if getter, ok := resp.(diffUserDataGetter); ok {
+			if existing := getter.GetDiffUserData(); len(existing) > 0 {
+				setUpdateNamesTrailer(ctx, existing)
+				return resp, nil
+			}
+		}
+
+		after, err := users.LoadUser(userId)
+		if err != nil {
+			return resp, nil
+		}
+
+		changed := userdata.ChangedTables(&before, &after)
+		if len(changed) == 0 {
+			return resp, nil
+		}
+
+		diff := userdata.ComputeDelta(&before, &after, changed)
+		reflect.ValueOf(resp).Elem().FieldByName("DiffUserData").Set(reflect.ValueOf(diff))
+		setUpdateNamesTrailer(ctx, diff)
+
+		return resp, nil
+	}
+}
+
+func skipDiffForMethod(method string) bool {
+	switch method {
+	case "/apb.api.user.UserService/Auth",
+		"/apb.api.user.UserService/RegisterUser",
+		"/apb.api.user.UserService/TransferUser",
+		"/apb.api.user.UserService/TransferUserByFacebook",
+		"/apb.api.config.ConfigService/GetConfig",
+		"/apb.api.data.DataService/GetLatestMasterDataVersion",
+		"/apb.api.data.DataService/GetUserDataNameV2",
+		"/apb.api.data.DataService/GetUserData":
+		return true
+	}
+	return false
+}
+
+func setUpdateNamesTrailer(ctx context.Context, diff map[string]*pb.DiffData) {
+	if len(diff) == 0 {
+		return
+	}
+	keys := make([]string, 0, len(diff))
+	for key := range diff {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	value := strings.Join(keys, ",")
+	if err := grpc.SetTrailer(ctx, metadata.Pairs("x-apb-update-user-data-names", value)); err != nil {
+		log.Printf("[DiffInterceptor] failed to set trailer: %v", err)
+	}
+}