GH-9612 Add plugin API for GetChannelStats method (#9627)

* Add GetChannelStats plugin api

* Fix to return channel stats correctly

* Add server version; Handle error idiomatically

4 files changed, 67 insertions, 0 deletions

diff --git a/app/plugin_api.go b/app/plugin_api.go
index c409a88f8..a07a07652 100644
--- a/app/plugin_api.go
+++ b/app/plugin_api.go
@@ -261,6 +261,14 @@ func (api *PluginAPI) GetChannelsForTeamForUser(teamId, userId string, includeDe
 	return api.app.GetChannelsForUser(teamId, userId, includeDeleted)
 }
 
+func (api *PluginAPI) GetChannelStats(channelId string) (*model.ChannelStats, *model.AppError) {
+	memberCount, err := api.app.GetChannelMemberCount(channelId)
+	if err != nil {
+		return nil, err
+	}
+	return &model.ChannelStats{ChannelId: channelId, MemberCount: memberCount}, nil
+}
+
 func (api *PluginAPI) GetDirectChannel(userId1, userId2 string) (*model.Channel, *model.AppError) {
 	return api.app.GetDirectChannel(userId1, userId2)
 }
diff --git a/plugin/api.go b/plugin/api.go
index 93b5a6d2e..f1b9ec01f 100644
--- a/plugin/api.go
+++ b/plugin/api.go
@@ -155,6 +155,11 @@ type API interface {
 	// Minimum server version: 5.6
 	GetChannelsForTeamForUser(teamId, userId string, includeDeleted bool) (*model.ChannelList, *model.AppError)
 
+	// GetChannelStats gets statistics for a channel.
+	//
+	// Minimum server version: 5.6
+	GetChannelStats(channelId string) (*model.ChannelStats, *model.AppError)
+
 	// GetDirectChannel gets a direct message channel.
 	GetDirectChannel(userId1, userId2 string) (*model.Channel, *model.AppError)
 
diff --git a/plugin/client_rpc_generated.go b/plugin/client_rpc_generated.go
index b3886dcb3..81469a20f 100644
--- a/plugin/client_rpc_generated.go
+++ b/plugin/client_rpc_generated.go
@@ -1660,6 +1660,35 @@ func (s *apiRPCServer) GetChannelsForTeamForUser(args *Z_GetChannelsForTeamForUs
 	return nil
 }
 
+type Z_GetChannelStatsArgs struct {
+	A string
+}
+
+type Z_GetChannelStatsReturns struct {
+	A *model.ChannelStats
+	B *model.AppError
+}
+
+func (g *apiRPCClient) GetChannelStats(channelId string) (*model.ChannelStats, *model.AppError) {
+	_args := &Z_GetChannelStatsArgs{channelId}
+	_returns := &Z_GetChannelStatsReturns{}
+	if err := g.client.Call("Plugin.GetChannelStats", _args, _returns); err != nil {
+		log.Printf("RPC call to GetChannelStats API failed: %s", err.Error())
+	}
+	return _returns.A, _returns.B
+}
+
+func (s *apiRPCServer) GetChannelStats(args *Z_GetChannelStatsArgs, returns *Z_GetChannelStatsReturns) error {
+	if hook, ok := s.impl.(interface {
+		GetChannelStats(channelId string) (*model.ChannelStats, *model.AppError)
+	}); ok {
+		returns.A, returns.B = hook.GetChannelStats(args.A)
+	} else {
+		return encodableError(fmt.Errorf("API GetChannelStats called but not implemented."))
+	}
+	return nil
+}
+
 type Z_GetDirectChannelArgs struct {
 	A string
 	B string
diff --git a/plugin/plugintest/api.go b/plugin/plugintest/api.go
index 81462e58d..d24b955ae 100644
--- a/plugin/plugintest/api.go
+++ b/plugin/plugintest/api.go
@@ -483,6 +483,31 @@ func (_m *API) GetChannelsForTeamForUser(teamId string, userId string, includeDe
 	return r0, r1
 }
 
+// GetChannelStats provides a mock function with given fields: channelId
+func (_m *API) GetChannelStats(channelId string) (*model.ChannelStats, *model.AppError) {
+	ret := _m.Called(channelId)
+
+	var r0 *model.ChannelStats
+	if rf, ok := ret.Get(0).(func(string) *model.ChannelStats); ok {
+		r0 = rf(channelId)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*model.ChannelStats)
+		}
+	}
+
+	var r1 *model.AppError
+	if rf, ok := ret.Get(1).(func(string) *model.AppError); ok {
+		r1 = rf(channelId)
+	} else {
+		if ret.Get(1) != nil {
+			r1 = ret.Get(1).(*model.AppError)
+		}
+	}
+
+	return r0, r1
+}
+
 // GetConfig provides a mock function with given fields:
 func (_m *API) GetConfig() *model.Config {
 	ret := _m.Called()