[MM-25659] ability to permanent delete channel through client (#15202)

Summary

    Ability to permanent delete channel through client

Ticket Link

    https://mattermost.atlassian.net/browse/MM-25659

api4/channel.go

@@ -1074,7 +1074,15 @@ func deleteChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	err = c.App.DeleteChannel(channel, c.App.Session().UserId)
+	if c.Params.Permanent {
+		if *c.App.Config().ServiceSettings.EnableAPIChannelDeletion {
+			err = c.App.PermanentDeleteChannel(channel)
+		} else {
+			err = model.NewAppError("deleteChannel", "api.user.delete_channel.not_enabled.app_error", nil, "channelId="+c.Params.ChannelId, http.StatusUnauthorized)
+		}
+	} else {
+		err = c.App.DeleteChannel(channel, c.App.Session().UserId)
+	}
 	if err != nil {
 		c.Err = err
 		return

api4/channel_local.go

@@ -15,7 +15,7 @@ func (api *API) InitChannelLocal() {
 	api.BaseRoutes.Channels.Handle("", api.ApiLocal(localCreateChannel)).Methods("POST")
 	api.BaseRoutes.Channel.Handle("", api.ApiLocal(getChannel)).Methods("GET")
 	api.BaseRoutes.ChannelByName.Handle("", api.ApiLocal(getChannelByName)).Methods("GET")
-	api.BaseRoutes.Channel.Handle("", api.ApiLocal(deleteChannel)).Methods("DELETE")
+	api.BaseRoutes.Channel.Handle("", api.ApiLocal(localDeleteChannel)).Methods("DELETE")
 	api.BaseRoutes.Channel.Handle("/patch", api.ApiLocal(localPatchChannel)).Methods("PUT")
 	api.BaseRoutes.Channel.Handle("/move", api.ApiLocal(localMoveChannel)).Methods("POST")
 
@@ -277,3 +277,40 @@ func localMoveChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	w.Write([]byte(channel.ToJson()))
 }
+
+func localDeleteChannel(c *Context, w http.ResponseWriter, r *http.Request) {
+	c.RequireChannelId()
+	if c.Err != nil {
+		return
+	}
+
+	channel, err := c.App.GetChannel(c.Params.ChannelId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	auditRec := c.MakeAuditRecord("localDeleteChannel", audit.Fail)
+	defer c.LogAuditRec(auditRec)
+	auditRec.AddMeta("channeld", channel)
+
+	if channel.Type == model.CHANNEL_DIRECT || channel.Type == model.CHANNEL_GROUP {
+		c.Err = model.NewAppError("localDeleteChannel", "api.channel.delete_channel.type.invalid", nil, "", http.StatusBadRequest)
+		return
+	}
+
+	if c.Params.Permanent {
+		err = c.App.PermanentDeleteChannel(channel)
+	} else {
+		err = c.App.DeleteChannel(channel, "")
+	}
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	auditRec.Success()
+	c.LogAudit("name=" + channel.Name)
+
+	ReturnStatusOK(w)
+}

api4/channel_test.go

@@ -1629,6 +1629,45 @@ func TestDeleteChannel2(t *testing.T) {
 	CheckForbiddenStatus(t, resp)
 }
 
+func TestPermanentDeleteChannel(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	enableAPIChannelDeletion := *th.App.Config().ServiceSettings.EnableAPIChannelDeletion
+	defer func() {
+		th.App.UpdateConfig(func(cfg *model.Config) { cfg.ServiceSettings.EnableAPIChannelDeletion = &enableAPIChannelDeletion })
+	}()
+
+	th.App.UpdateConfig(func(cfg *model.Config) { *cfg.ServiceSettings.EnableAPIChannelDeletion = false })
+
+	publicChannel1 := th.CreatePublicChannel()
+	t.Run("Permanent deletion not available through API if EnableAPIChannelDeletion is not set", func(t *testing.T) {
+		_, resp := th.SystemAdminClient.PermanentDeleteChannel(publicChannel1.Id)
+		CheckUnauthorizedStatus(t, resp)
+	})
+
+	t.Run("Permanent deletion available through local mode even if EnableAPIChannelDeletion is not set", func(t *testing.T) {
+		ok, resp := th.LocalClient.PermanentDeleteChannel(publicChannel1.Id)
+		CheckNoError(t, resp)
+		assert.True(t, ok)
+	})
+
+	th.App.UpdateConfig(func(cfg *model.Config) { *cfg.ServiceSettings.EnableAPIChannelDeletion = true })
+	th.TestForSystemAdminAndLocal(t, func(t *testing.T, c *model.Client4) {
+		publicChannel := th.CreatePublicChannel()
+		ok, resp := c.PermanentDeleteChannel(publicChannel.Id)
+		CheckNoError(t, resp)
+		assert.True(t, ok)
+
+		_, err := th.App.GetChannel(publicChannel.Id)
+		assert.NotNil(t, err)
+
+		ok, resp = c.PermanentDeleteChannel("junk")
+		CheckBadRequestStatus(t, resp)
+		require.False(t, ok, "should have returned false")
+	}, "Permanent deletion with EnableAPIChannelDeletion set")
+}
+
 func TestConvertChannelToPrivate(t *testing.T) {
 	th := Setup(t).InitBasic()
 	defer th.TearDown()

app/channel.go

@@ -2345,10 +2345,18 @@ func (a *App) PermanentDeleteChannel(channel *model.Channel) *model.AppError {
 		return model.NewAppError("PermanentDeleteChannel", "app.webhooks.permanent_delete_outgoing_by_channel.app_error", nil, err.Error(), http.StatusInternalServerError)
 	}
 
+	deleteAt := model.GetMillis()
+
 	if nErr := a.Srv().Store.Channel().PermanentDelete(channel.Id); nErr != nil {
 		return model.NewAppError("PermanentDeleteChannel", "app.channel.permanent_delete.app_error", nil, nErr.Error(), http.StatusInternalServerError)
 	}
 
+	a.invalidateCacheForChannel(channel)
+	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_CHANNEL_DELETED, channel.TeamId, "", "", nil)
+	message.Add("channel_id", channel.Id)
+	message.Add("delete_at", deleteAt)
+	a.Publish(message)
+
 	return nil
 }
 

i18n/en.json

@@ -2754,6 +2754,10 @@
     "id": "api.user.create_user.signup_link_invalid.app_error",
     "translation": "The signup link does not appear to be valid."
   },
+  {
+    "id": "api.user.delete_channel.not_enabled.app_error",
+    "translation": "Permanent channel deletion feature is not enabled. Please contact your System Administrator."
+  },
   {
     "id": "api.user.delete_team.not_enabled.app_error",
     "translation": "Permanent team deletion feature is not enabled. Please contact your System Administrator."

model/client4.go

@@ -2562,6 +2562,16 @@ func (c *Client4) DeleteChannel(channelId string) (bool, *Response) {
 	return CheckStatusOK(r), BuildResponse(r)
 }
 
+// PermanentDeleteChannel deletes a channel based on the provided channel id string.
+func (c *Client4) PermanentDeleteChannel(channelId string) (bool, *Response) {
+	r, err := c.DoApiDelete(c.GetChannelRoute(channelId) + "?permanent=" + c.boolString(true))
+	if err != nil {
+		return false, BuildErrorResponse(r, err)
+	}
+	defer closeBody(r)
+	return CheckStatusOK(r), BuildResponse(r)
+}
+
 // MoveChannel moves the channel to the destination team.
 func (c *Client4) MoveChannel(channelId, teamId string, force bool) (*Channel, *Response) {
 	requestBody := map[string]interface{}{

model/config.go

@@ -329,6 +329,7 @@ type ServiceSettings struct {
 	DEPRECATED_DO_NOT_USE_ImageProxyOptions           *string `json:"ImageProxyOptions" mapstructure:"ImageProxyOptions"` // This field is deprecated and must not be used.
 	EnableAPITeamDeletion                             *bool
 	EnableAPIUserDeletion                             *bool
+	EnableAPIChannelDeletion                          *bool
 	ExperimentalEnableHardenedMode                    *bool
 	DisableLegacyMFA                                  *bool `restricted:"true"`
 	ExperimentalStrictCSRFEnforcement                 *bool `restricted:"true"`
@@ -705,6 +706,10 @@ func (s *ServiceSettings) SetDefaults(isUpdate bool) {
 		s.EnableAPIUserDeletion = NewBool(false)
 	}
 
+	if s.EnableAPIChannelDeletion == nil {
+		s.EnableAPIChannelDeletion = NewBool(false)
+	}
+
 	if s.ExperimentalEnableHardenedMode == nil {
 		s.ExperimentalEnableHardenedMode = NewBool(false)
 	}