[PLT-5864] Move teammate name display setting to the System Console (#6681)

* move teammate name display setting to the system console

* update all the likes of TeammateNameDisplay names

* fix gofmt error

* rebase and fix conflict

4 files changed, 40 insertions, 24 deletions

diff --git a/model/config.go b/model/config.go
index 6d62aab91..5662ee9c0 100644
--- a/model/config.go
+++ b/model/config.go
@@ -39,6 +39,10 @@ const (
 	DIRECT_MESSAGE_ANY  = "any"
 	DIRECT_MESSAGE_TEAM = "team"
 
+	SHOW_USERNAME          = "username"
+	SHOW_NICKNAME_FULLNAME = "nickname_full_name"
+	SHOW_FULLNAME          = "full_name"
+
 	PERMISSIONS_ALL           = "all"
 	PERMISSIONS_CHANNEL_ADMIN = "channel_admin"
 	PERMISSIONS_TEAM_ADMIN    = "team_admin"
@@ -322,6 +326,7 @@ type TeamSettings struct {
 	UserStatusAwayTimeout               *int64
 	MaxChannelsPerTeam                  *int64
 	MaxNotificationsPerChannel          *int64
+	TeammateNameDisplay                 *string
 }
 
 type LdapSettings struct {
@@ -702,6 +707,11 @@ func (o *Config) SetDefaults() {
 		*o.TeamSettings.MaxNotificationsPerChannel = 1000
 	}
 
+	if o.TeamSettings.TeammateNameDisplay == nil {
+		o.TeamSettings.TeammateNameDisplay = new(string)
+		*o.TeamSettings.TeammateNameDisplay = SHOW_FULLNAME
+	}
+
 	if o.EmailSettings.EnableSignInWithEmail == nil {
 		o.EmailSettings.EnableSignInWithEmail = new(bool)
 
@@ -1394,6 +1404,10 @@ func (o *Config) IsValid() *AppError {
 		return NewLocAppError("Config.IsValid", "model.config.is_valid.restrict_direct_message.app_error", nil, "")
 	}
 
+	if !(*o.TeamSettings.TeammateNameDisplay == SHOW_FULLNAME || *o.TeamSettings.TeammateNameDisplay == SHOW_NICKNAME_FULLNAME || *o.TeamSettings.TeammateNameDisplay == SHOW_USERNAME) {
+		return NewLocAppError("Config.IsValid", "model.config.is_valid.teammate_name_display.app_error", nil, "")
+	}
+
 	if len(o.SqlSettings.AtRestEncryptKey) < 32 {
 		return NewLocAppError("Config.IsValid", "model.config.is_valid.encrypt_sql.app_error", nil, "")
 	}
diff --git a/model/preference.go b/model/preference.go
index 4d534b17b..589f8b5a9 100644
--- a/model/preference.go
+++ b/model/preference.go
@@ -17,13 +17,8 @@ const (
 	PREFERENCE_CATEGORY_ADVANCED_SETTINGS   = "advanced_settings"
 	PREFERENCE_CATEGORY_FLAGGED_POST        = "flagged_post"
 
-	PREFERENCE_CATEGORY_DISPLAY_SETTINGS   = "display_settings"
-	PREFERENCE_NAME_COLLAPSE_SETTING       = "collapse_previews"
-	PREFERENCE_NAME_DISPLAY_NAME_FORMAT    = "name_format"
-	PREFERENCE_VALUE_DISPLAY_NAME_NICKNAME = "nickname_full_name"
-	PREFERENCE_VALUE_DISPLAY_NAME_FULL     = "full_name"
-	PREFERENCE_VALUE_DISPLAY_NAME_USERNAME = "username"
-	PREFERENCE_DEFAULT_DISPLAY_NAME_FORMAT = PREFERENCE_VALUE_DISPLAY_NAME_USERNAME
+	PREFERENCE_CATEGORY_DISPLAY_SETTINGS = "display_settings"
+	PREFERENCE_NAME_COLLAPSE_SETTING     = "collapse_previews"
 
 	PREFERENCE_CATEGORY_THEME = "theme"
 	// the name for theme props is the team id
diff --git a/model/user.go b/model/user.go
index 970e777fc..8e5c8fcc1 100644
--- a/model/user.go
+++ b/model/user.go
@@ -383,26 +383,16 @@ func (u *User) GetFullName() string {
 	}
 }
 
-func (u *User) GetDisplayName() string {
-	if u.Nickname != "" {
-		return u.Nickname
-	} else if fullName := u.GetFullName(); fullName != "" {
-		return fullName
-	} else {
-		return u.Username
-	}
-}
-
-func (u *User) GetDisplayNameForPreference(nameFormat string) string {
+func (u *User) GetDisplayName(nameFormat string) string {
 	displayName := u.Username
 
-	if nameFormat == PREFERENCE_VALUE_DISPLAY_NAME_NICKNAME {
+	if nameFormat == SHOW_NICKNAME_FULLNAME {
 		if u.Nickname != "" {
 			displayName = u.Nickname
 		} else if fullName := u.GetFullName(); fullName != "" {
 			displayName = fullName
 		}
-	} else if nameFormat == PREFERENCE_VALUE_DISPLAY_NAME_FULL {
+	} else if nameFormat == SHOW_FULLNAME {
 		if fullName := u.GetFullName(); fullName != "" {
 			displayName = fullName
 		}
diff --git a/model/user_test.go b/model/user_test.go
index fc153248f..4502263c3 100644
--- a/model/user_test.go
+++ b/model/user_test.go
@@ -179,20 +179,37 @@ func TestUserGetFullName(t *testing.T) {
 }
 
 func TestUserGetDisplayName(t *testing.T) {
-	user := User{Username: "user"}
+	user := User{Username: "username"}
+
+	if displayName := user.GetDisplayName(SHOW_FULLNAME); displayName != "username" {
+		t.Fatal("Display name should be username")
+	}
+
+	if displayName := user.GetDisplayName(SHOW_NICKNAME_FULLNAME); displayName != "username" {
+		t.Fatal("Display name should be username")
+	}
 
-	if displayName := user.GetDisplayName(); displayName != "user" {
+	if displayName := user.GetDisplayName(SHOW_USERNAME); displayName != "username" {
 		t.Fatal("Display name should be username")
 	}
 
 	user.FirstName = "first"
 	user.LastName = "last"
-	if displayName := user.GetDisplayName(); displayName != "first last" {
+
+	if displayName := user.GetDisplayName(SHOW_FULLNAME); displayName != "first last" {
 		t.Fatal("Display name should be full name")
 	}
 
+	if displayName := user.GetDisplayName(SHOW_NICKNAME_FULLNAME); displayName != "first last" {
+		t.Fatal("Display name should be full name since there is no nickname")
+	}
+
+	if displayName := user.GetDisplayName(SHOW_USERNAME); displayName != "username" {
+		t.Fatal("Display name should be username")
+	}
+
 	user.Nickname = "nickname"
-	if displayName := user.GetDisplayName(); displayName != "nickname" {
+	if displayName := user.GetDisplayName(SHOW_NICKNAME_FULLNAME); displayName != "nickname" {
 		t.Fatal("Display name should be nickname")
 	}
 }