GH-9636 plugins api GetUsersInChannelByStatus (#9645)

* adds GetUsersInChannelByStatus to plugin api with generated rpc code.

* fixed typo in comment with actual func name

* replaced Response model with AppError in output of GetUsersInChannelByStatus

* removed etag param from GetUsersInChannelByStatus since it is not used

* plugin api for GetUsersInChannelByStatus updated to take the limit, conforming to the app api.

* fixed an issue in my own logic on app/plugin integration.

* adds GetUsersInChannelByStatus to plugin api with generated rpc code.

* fixed typo in comment with actual func name

* replaced Response model with AppError in output of GetUsersInChannelByStatus

* removed etag param from GetUsersInChannelByStatus since it is not used

* plugin api for GetUsersInChannelByStatus updated to take the limit, conforming to the app api.

* fixed an issue in my own logic on app/plugin integration.

* GetUsersInChannelByStatus changed to more generic GetUsersInChannel which takes a sortBy parameter, allowing for more granular/extensible sorting functionality in the future

* GetUsersInChannel accepts sort parameter of 'username' and 'status'. Both values are consts in model pkg.

* Documents minimum server version for GetUsersInChannel.

* adds GetUsersInChannelByStatus to plugin api with generated rpc code.

* fixed typo in comment with actual func name

* replaced Response model with AppError in output of GetUsersInChannelByStatus

* removed etag param from GetUsersInChannelByStatus since it is not used

* plugin api for GetUsersInChannelByStatus updated to take the limit, conforming to the app api.

* fixed an issue in my own logic on app/plugin integration.

* adds GetUsersInChannelByStatus to plugin api with generated rpc code.

* Resolved conflict on rebase

* replaced Response model with AppError in output of GetUsersInChannelByStatus

* removed etag param from GetUsersInChannelByStatus since it is not used

* plugin api for GetUsersInChannelByStatus updated to take the limit, conforming to the app api.

* fixed an issue in my own logic on app/plugin integration.

* GetUsersInChannelByStatus changed to more generic GetUsersInChannel which takes a sortBy parameter, allowing for more granular/extensible sorting functionality in the future

* GetUsersInChannel accepts sort parameter of 'username' and 'status'. Both values are consts in model pkg.

* Documents minimum server version for GetUsersInChannel.

* replaces GetUsersInChannel from #9608 / #9643 with sortBy functionality

6 files changed, 67 insertions, 53 deletions

diff --git a/app/plugin_api.go b/app/plugin_api.go
index 48f07275e..3bb638a24 100644
--- a/app/plugin_api.go
+++ b/app/plugin_api.go
@@ -200,6 +200,18 @@ func (api *PluginAPI) UpdateUserStatus(userId, status string) (*model.Status, *m
 
 	return api.app.GetStatus(userId)
 }
+
+func (api *PluginAPI) GetUsersInChannel(channelId, sortBy string, page, perPage int) ([]*model.User, *model.AppError) {
+	switch sortBy {
+	case model.CHANNEL_SORT_BY_USERNAME:
+		return api.app.GetUsersInChannel(channelId, page*perPage, perPage)
+	case model.CHANNEL_SORT_BY_STATUS:
+		return api.app.GetUsersInChannelByStatus(channelId, page*perPage, perPage)
+	default:
+		return nil, model.NewAppError("GetUsersInChannel", "plugin.api.get_users_in_channel", nil, "invalid sort option", http.StatusBadRequest)
+	}
+}
+
 func (api *PluginAPI) GetLDAPUserAttributes(userId string, attributes []string) (map[string]string, *model.AppError) {
 	if api.app.Ldap == nil {
 		return nil, model.NewAppError("GetLdapUserAttributes", "ent.ldap.disabled.app_error", nil, "", http.StatusNotImplemented)
@@ -298,10 +310,6 @@ func (api *PluginAPI) DeleteChannelMember(channelId, userId string) *model.AppEr
 	return api.app.LeaveChannel(channelId, userId)
 }
 
-func (api *PluginAPI) GetUsersInChannel(channelId string, page int, perPage int) ([]*model.User, *model.AppError) {
-	return api.app.GetUsersInChannel(channelId, page*perPage, perPage)
-}
-
 func (api *PluginAPI) CreatePost(post *model.Post) (*model.Post, *model.AppError) {
 	return api.app.CreatePostMissingChannel(post, true)
 }
diff --git a/model/channel.go b/model/channel.go
index 529c49d35..f8867babb 100644
--- a/model/channel.go
+++ b/model/channel.go
@@ -29,6 +29,9 @@ const (
 	CHANNEL_HEADER_MAX_RUNES       = 1024
 	CHANNEL_PURPOSE_MAX_RUNES      = 250
 	CHANNEL_CACHE_SIZE             = 25000
+
+	CHANNEL_SORT_BY_USERNAME = "username"
+	CHANNEL_SORT_BY_STATUS   = "status"
 )
 
 type Channel struct {
diff --git a/model/client4.go b/model/client4.go
index a9b4d3826..cce3b62ef 100644
--- a/model/client4.go
+++ b/model/client4.go
@@ -832,7 +832,7 @@ func (c *Client4) GetUsersInChannel(channelId string, page int, perPage int, eta
 	}
 }
 
-// GetUsersInChannelStatus returns a page of users in a channel. Page counting starts at 0. Sorted by Status
+// GetUsersInChannelByStatus returns a page of users in a channel. Page counting starts at 0. Sorted by Status
 func (c *Client4) GetUsersInChannelByStatus(channelId string, page int, perPage int, etag string) ([]*User, *Response) {
 	query := fmt.Sprintf("?in_channel=%v&page=%v&per_page=%v&sort=status", channelId, page, perPage)
 	if r, err := c.DoApiGet(c.GetUsersRoute()+query, etag); err != nil {
diff --git a/plugin/api.go b/plugin/api.go
index dc60bb57a..0f481784e 100644
--- a/plugin/api.go
+++ b/plugin/api.go
@@ -77,6 +77,12 @@ type API interface {
 	// The status parameter can be: "online", "away", "dnd", or "offline".
 	UpdateUserStatus(userId, status string) (*model.Status, *model.AppError)
 
+	// GetUsersInChannel returns a page of users in a channel. Page counting starts at 0.
+	// The sortBy parameter can be: "username" or "status".
+	//
+	// Minimum server version: 5.6
+	GetUsersInChannel(channelId, sortBy string, page, perPage int) ([]*model.User, *model.AppError)
+
 	// GetLDAPUserAttributes will return LDAP attributes for a user.
 	// The attributes parameter should be a list of attributes to pull.
 	// Returns a map with attribute names as keys and the user's attributes as values.
@@ -183,11 +189,6 @@ type API interface {
 	// DeleteChannelMember deletes a channel membership for a user.
 	DeleteChannelMember(channelId, userId string) *model.AppError
 
-	// GetUsersInChannel gets users in given channel.
-	//
-	// Minimum server version: 5.6
-	GetUsersInChannel(channelId string, page int, perPage int) ([]*model.User, *model.AppError)
-
 	// CreatePost creates a post.
 	CreatePost(post *model.Post) (*model.Post, *model.AppError)
 
diff --git a/plugin/client_rpc_generated.go b/plugin/client_rpc_generated.go
index d99b7b0e6..7ed016c24 100644
--- a/plugin/client_rpc_generated.go
+++ b/plugin/client_rpc_generated.go
@@ -1004,6 +1004,38 @@ func (s *apiRPCServer) UpdateUserStatus(args *Z_UpdateUserStatusArgs, returns *Z
 	return nil
 }
 
+type Z_GetUsersInChannelArgs struct {
+	A string
+	B string
+	C int
+	D int
+}
+
+type Z_GetUsersInChannelReturns struct {
+	A []*model.User
+	B *model.AppError
+}
+
+func (g *apiRPCClient) GetUsersInChannel(channelId, sortBy string, page, perPage int) ([]*model.User, *model.AppError) {
+	_args := &Z_GetUsersInChannelArgs{channelId, sortBy, page, perPage}
+	_returns := &Z_GetUsersInChannelReturns{}
+	if err := g.client.Call("Plugin.GetUsersInChannel", _args, _returns); err != nil {
+		log.Printf("RPC call to GetUsersInChannel API failed: %s", err.Error())
+	}
+	return _returns.A, _returns.B
+}
+
+func (s *apiRPCServer) GetUsersInChannel(args *Z_GetUsersInChannelArgs, returns *Z_GetUsersInChannelReturns) error {
+	if hook, ok := s.impl.(interface {
+		GetUsersInChannel(channelId, sortBy string, page, perPage int) ([]*model.User, *model.AppError)
+	}); ok {
+		returns.A, returns.B = hook.GetUsersInChannel(args.A, args.B, args.C, args.D)
+	} else {
+		return encodableError(fmt.Errorf("API GetUsersInChannel called but not implemented."))
+	}
+	return nil
+}
+
 type Z_GetLDAPUserAttributesArgs struct {
 	A string
 	B []string
@@ -1928,37 +1960,6 @@ func (s *apiRPCServer) DeleteChannelMember(args *Z_DeleteChannelMemberArgs, retu
 	return nil
 }
 
-type Z_GetUsersInChannelArgs struct {
-	A string
-	B int
-	C int
-}
-
-type Z_GetUsersInChannelReturns struct {
-	A []*model.User
-	B *model.AppError
-}
-
-func (g *apiRPCClient) GetUsersInChannel(channelId string, page int, perPage int) ([]*model.User, *model.AppError) {
-	_args := &Z_GetUsersInChannelArgs{channelId, page, perPage}
-	_returns := &Z_GetUsersInChannelReturns{}
-	if err := g.client.Call("Plugin.GetUsersInChannel", _args, _returns); err != nil {
-		log.Printf("RPC call to GetUsersInChannel API failed: %s", err.Error())
-	}
-	return _returns.A, _returns.B
-}
-
-func (s *apiRPCServer) GetUsersInChannel(args *Z_GetUsersInChannelArgs, returns *Z_GetUsersInChannelReturns) error {
-	if hook, ok := s.impl.(interface {
-		GetUsersInChannel(channelId string, page int, perPage int) ([]*model.User, *model.AppError)
-	}); ok {
-		returns.A, returns.B = hook.GetUsersInChannel(args.A, args.B, args.C)
-	} else {
-		return encodableError(fmt.Errorf("API GetUsersInChannel called but not implemented."))
-	}
-	return nil
-}
-
 type Z_CreatePostArgs struct {
 	A *model.Post
 }
diff --git a/plugin/plugintest/api.go b/plugin/plugintest/api.go
index b3df3616f..4e94e17af 100644
--- a/plugin/plugintest/api.go
+++ b/plugin/plugintest/api.go
@@ -1243,13 +1243,13 @@ func (_m *API) GetUsersByUsernames(usernames []string) ([]*model.User, *model.Ap
 	return r0, r1
 }
 
-// GetUsersInTeam provides a mock function with given fields: teamId, page, perPage
-func (_m *API) GetUsersInTeam(teamId string, page int, perPage int) ([]*model.User, *model.AppError) {
-	ret := _m.Called(teamId, page, perPage)
+// GetUsersInChannel provides a mock function with given fields: channelId, sortBy, page, perPage
+func (_m *API) GetUsersInChannel(channelId string, sortBy string, page int, perPage int) ([]*model.User, *model.AppError) {
+	ret := _m.Called(channelId, sortBy, page, perPage)
 
 	var r0 []*model.User
-	if rf, ok := ret.Get(0).(func(string, int, int) []*model.User); ok {
-		r0 = rf(teamId, page, perPage)
+	if rf, ok := ret.Get(0).(func(string, string, int, int) []*model.User); ok {
+		r0 = rf(channelId, sortBy, page, perPage)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).([]*model.User)
@@ -1257,8 +1257,9 @@ func (_m *API) GetUsersInTeam(teamId string, page int, perPage int) ([]*model.Us
 	}
 
 	var r1 *model.AppError
-	if rf, ok := ret.Get(1).(func(string, int, int) *model.AppError); ok {
-		r1 = rf(teamId, page, perPage)
+
+	if rf, ok := ret.Get(1).(func(string, string, int, int) *model.AppError); ok {
+		r1 = rf(channelId, sortBy, page, perPage)
 	} else {
 		if ret.Get(1) != nil {
 			r1 = ret.Get(1).(*model.AppError)
@@ -1268,13 +1269,13 @@ func (_m *API) GetUsersInTeam(teamId string, page int, perPage int) ([]*model.Us
 	return r0, r1
 }
 
-// GetUsersInChannel provides a mock function with given fields: channelId, page, perPage
-func (_m *API) GetUsersInChannel(channelId string, page int, perPage int) ([]*model.User, *model.AppError) {
-	ret := _m.Called(channelId, page, perPage)
+// GetUsersInTeam provides a mock function with given fields: teamId, page, perPage
+func (_m *API) GetUsersInTeam(teamId string, page int, perPage int) ([]*model.User, *model.AppError) {
+	ret := _m.Called(teamId, page, perPage)
 
 	var r0 []*model.User
 	if rf, ok := ret.Get(0).(func(string, int, int) []*model.User); ok {
-		r0 = rf(channelId, page, perPage)
+		r0 = rf(teamId, page, perPage)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).([]*model.User)
@@ -1283,7 +1284,7 @@ func (_m *API) GetUsersInChannel(channelId string, page int, perPage int) ([]*mo
 
 	var r1 *model.AppError
 	if rf, ok := ret.Get(1).(func(string, int, int) *model.AppError); ok {
-		r1 = rf(channelId, page, perPage)
+		r1 = rf(teamId, page, perPage)
 	} else {
 		if ret.Get(1) != nil {
 			r1 = ret.Get(1).(*model.AppError)