feat: add custom username suggestions pool (#1644)

* :sparkles: add custom username suggestions pool

* :children_crossing: add minimum of 10 suggested usernames until custom pool is used

6 files changed, 71 insertions, 11 deletions

diff --git a/controllers/admin/config.go b/controllers/admin/config.go
index 7f4dcae3e..e2fd85a2a 100644
--- a/controllers/admin/config.go
+++ b/controllers/admin/config.go
@@ -603,6 +603,27 @@ func SetForbiddenUsernameList(w http.ResponseWriter, r *http.Request) {
 	controllers.WriteSimpleResponse(w, true, "forbidden username list updated")
 }
 
+// SetSuggestedUsernameList will set the list of suggested usernames that newly registered users are assigned if it isn't inferred otherwise (i.e. through a proxy).
+func SetSuggestedUsernameList(w http.ResponseWriter, r *http.Request) {
+	type suggestedUsernameListRequest struct {
+		Value []string `json:"value"`
+	}
+
+	decoder := json.NewDecoder(r.Body)
+	var request suggestedUsernameListRequest
+
+	if err := decoder.Decode(&request); err != nil {
+		controllers.WriteSimpleResponse(w, false, "unable to update suggested usernames with provided values")
+		return
+	}
+
+	if err := data.SetSuggestedUsernamesList(request.Value); err != nil {
+		controllers.WriteSimpleResponse(w, false, err.Error())
+	}
+
+	controllers.WriteSimpleResponse(w, true, "suggested username list updated")
+}
+
 func requirePOST(w http.ResponseWriter, r *http.Request) bool {
 	if r.Method != controllers.POST {
 		controllers.WriteSimpleResponse(w, false, r.Method+" not supported")
diff --git a/controllers/admin/serverConfig.go b/controllers/admin/serverConfig.go
index 328edf6e5..8270e9622 100644
--- a/controllers/admin/serverConfig.go
+++ b/controllers/admin/serverConfig.go
@@ -17,6 +17,7 @@ import (
 func GetServerConfig(w http.ResponseWriter, r *http.Request) {
 	ffmpeg := utils.ValidatedFfmpegPath(data.GetFfMpegPath())
 	usernameBlocklist := data.GetForbiddenUsernameList()
+	usernameSuggestions := data.GetSuggestedUsernamesList()
 
 	videoQualityVariants := make([]models.StreamOutputVariant, 0)
 	for _, variant := range data.GetStreamOutputVariants() {
@@ -64,6 +65,7 @@ func GetServerConfig(w http.ResponseWriter, r *http.Request) {
 		SupportedCodecs:    transcoder.GetCodecs(ffmpeg),
 		VideoCodec:         data.GetVideoCodec(),
 		ForbiddenUsernames: usernameBlocklist,
+		SuggestedUsernames: usernameSuggestions,
 	}
 
 	w.Header().Set("Content-Type", "application/json")
@@ -89,6 +91,7 @@ type serverConfigAdminResponse struct {
 	SupportedCodecs    []string                `json:"supportedCodecs"`
 	VideoCodec         string                  `json:"videoCodec"`
 	ForbiddenUsernames []string                `json:"forbiddenUsernames"`
+	SuggestedUsernames []string                `json:"suggestedUsernames"`
 }
 
 type videoSettings struct {
diff --git a/core/data/config.go b/core/data/config.go
index c8beb0152..0eaa0f57d 100644
--- a/core/data/config.go
+++ b/core/data/config.go
@@ -42,6 +42,7 @@ const externalActionsKey = "external_actions"
 const customStylesKey = "custom_styles"
 const videoCodecKey = "video_codec"
 const blockedUsernamesKey = "blocked_usernames"
+const suggestedUsernamesKey = "suggested_usernames"
 
 // GetExtraPageBodyContent will return the user-supplied body content.
 func GetExtraPageBodyContent() string {
@@ -601,3 +602,23 @@ func SetForbiddenUsernameList(usernames []string) error {
 	usernameListString := strings.Join(usernames, ",")
 	return _datastore.SetString(blockedUsernamesKey, usernameListString)
 }
+
+// GetSuggestedUsernamesList will return the suggested usernames as a comma separated string.
+// If the number of suggested usernames is smaller than 10, the number pool is not used (see code in the CreateAnonymousUser function).
+func GetSuggestedUsernamesList() []string {
+	usernameString, err := _datastore.GetString(suggestedUsernamesKey)
+
+	if err != nil || usernameString == "" {
+		return []string{}
+	}
+
+	suggestionList := strings.Split(usernameString, ",")
+
+	return suggestionList
+}
+
+// SetSuggestedUsernamesList sets the username suggestion list as a comma separated string.
+func SetSuggestedUsernamesList(usernames []string) error {
+	usernameListString := strings.Join(usernames, ",")
+	return _datastore.SetString(suggestedUsernamesKey, usernameListString)
+}
diff --git a/core/user/user.go b/core/user/user.go
index 3216828ce..218cb3d18 100644
--- a/core/user/user.go
+++ b/core/user/user.go
@@ -17,6 +17,7 @@ import (
 var _datastore *data.Datastore
 
 const moderatorScopeKey = "MODERATOR"
+const minSuggestedUsernamePoolLength = 10
 
 // User represents a single chat user.
 type User struct {
@@ -48,7 +49,7 @@ func SetupUsers() {
 }
 
 // CreateAnonymousUser will create a new anonymous user with the provided display name.
-func CreateAnonymousUser(username string) (*User, error) {
+func CreateAnonymousUser(displayName string) (*User, error) {
 	id := shortid.MustGenerate()
 	accessToken, err := utils.GenerateAccessToken()
 	if err != nil {
@@ -56,9 +57,15 @@ func CreateAnonymousUser(username string) (*User, error) {
 		return nil, err
 	}
 
-	displayName := username
 	if displayName == "" {
-		displayName = utils.GeneratePhrase()
+		suggestedUsernamesList := data.GetSuggestedUsernamesList()
+
+		if len(suggestedUsernamesList) >= minSuggestedUsernamePoolLength {
+			index := utils.RandomIndex(len(suggestedUsernamesList))
+			displayName = suggestedUsernamesList[index]
+		} else {
+			displayName = utils.GeneratePhrase()
+		}
 	}
 
 	displayColor := utils.GenerateRandomDisplayColor()
@@ -287,8 +294,8 @@ func GetModeratorUsers() []*User {
 				 substr(rest, instr(rest, ',')+1)
 			FROM split
 		   WHERE rest <> '')
-		SELECT id, display_name, scopes, display_color, created_at, disabled_at, previous_names, namechanged_at, scope 
-		  FROM split 
+		SELECT id, display_name, scopes, display_color, created_at, disabled_at, previous_names, namechanged_at, scope
+		  FROM split
 		 WHERE scope <> ''
 		 ORDER BY created_at
 	  ) AS token WHERE token.scope = ?`
diff --git a/router/router.go b/router/router.go
index 686104c42..23e46b7d8 100644
--- a/router/router.go
+++ b/router/router.go
@@ -142,6 +142,9 @@ func Start() error {
 	// Set chat usernames that are not allowed
 	http.HandleFunc("/api/admin/config/chat/forbiddenusernames", middleware.RequireAdminAuth(admin.SetForbiddenUsernameList))
 
+	// Set the suggested chat usernames that will be assigned automatically
+	http.HandleFunc("/api/admin/config/chat/suggestedusernames", middleware.RequireAdminAuth(admin.SetSuggestedUsernameList))
+
 	// Set video codec
 	http.HandleFunc("/api/admin/config/video/codec", middleware.RequireAdminAuth(admin.SetVideoCodec))
 
diff --git a/utils/phraseGenerator.go b/utils/phraseGenerator.go
index 7776b169a..104f86c88 100644
--- a/utils/phraseGenerator.go
+++ b/utils/phraseGenerator.go
@@ -10,7 +10,7 @@ import (
 
 var (
 	// taken from https://github.com/docker/docker/blob/master/pkg/namesgenerator/names-generator.go
-	left = [...]string{
+	left = []string{
 		"admiring",
 		"adoring",
 		"affectionate",
@@ -115,7 +115,7 @@ var (
 
 	// Docker, starting from 0.7.x, generates names from notable scientists and hackers.
 	// Please, for any amazing man that you add to the list, consider adding an equally amazing woman to it, and vice versa.
-	right = [...]string{
+	right = []string{
 		// Muhammad ibn Jābir al-Ḥarrānī al-Battānī was a founding father of astronomy. https://en.wikipedia.org/wiki/Mu%E1%B8%A5ammad_ibn_J%C4%81bir_al-%E1%B8%A4arr%C4%81n%C4%AB_al-Batt%C4%81n%C4%AB
 		"albattani",
 
@@ -628,10 +628,15 @@ var (
 
 // GeneratePhrase will generate and return a random string consisting of our word list.
 func GeneratePhrase() string {
-	r := rand.New(rand.NewSource(time.Now().UnixNano())) //nolint
-
-	leftIndex := int(r.Float32() * float32(len(left)))
-	rightIndex := int(r.Float32() * float32(len(right)))
+	leftIndex := RandomIndex(len(left))
+	rightIndex := RandomIndex(len(right))
 
 	return fmt.Sprintf("%s-%s", left[leftIndex], right[rightIndex])
 }
+
+// RandomIndex returns a random integer that is at most the `max` parameter.
+func RandomIndex(max int) int {
+	r := rand.New(rand.NewSource(time.Now().UnixNano())) //nolint
+
+	return int(r.Float32() * float32(max))
+}