MM-53358: Revert Threads Everywhere (#23882)

Remove changes related to the unshipped threads everywhere feature, including commits b8da473da7 and 9f9e19e05d.

Since a version of Playbooks shipped calling this experimental API, keep a `nil` implementation to avoid breaking compatibility. We remove the hooks altogether, but keep the numbering again to avoid breaking compatbility.

Fixes: https://mattermost.atlassian.net/browse/MM-53358

server/channels/app/app_iface.go

@@ -971,7 +971,6 @@ type AppIface interface {
 	RegenOutgoingWebhookToken(hook *model.OutgoingWebhook) (*model.OutgoingWebhook, *model.AppError)
 	RegenerateOAuthAppSecret(app *model.OAuthApp) (*model.OAuthApp, *model.AppError)
 	RegenerateTeamInviteId(teamID string) (*model.Team, *model.AppError)
-	RegisterCollectionAndTopic(pluginID, collectionType, topicType string) error
 	RegisterPluginCommand(pluginID string, command *model.Command) error
 	RegisterProductCommand(ProductID string, command *model.Command) error
 	ReloadConfig() error

server/channels/app/channels.go

@@ -83,12 +83,6 @@ type Channels struct {
 
 	postReminderMut  sync.Mutex
 	postReminderTask *model.ScheduledTask
-
-	// collectionTypes maps from collection types to the registering plugin id
-	collectionTypes map[string]string
-	// topicTypes maps from topic types to collection types
-	topicTypes                 map[string]string
-	collectionAndTopicTypesMut sync.Mutex
 }
 
 func init() {
@@ -111,11 +105,9 @@ func NewChannels(services map[product.ServiceKey]any) (*Channels, error) {
 		return nil, errors.New("server not passed")
 	}
 	ch := &Channels{
-		srv:             s,
-		imageProxy:      imageproxy.MakeImageProxy(s.platform, s.httpService, s.Log()),
-		uploadLockMap:   map[string]bool{},
-		collectionTypes: map[string]string{},
-		topicTypes:      map[string]string{},
+		srv:           s,
+		imageProxy:    imageproxy.MakeImageProxy(s.platform, s.httpService, s.Log()),
+		uploadLockMap: map[string]bool{},
 	}
 
 	// To get another service:

server/channels/app/collection.go

@@ -1,35 +0,0 @@
-// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
-// See LICENSE.txt for license information.
-
-package app
-
-import (
-	"net/http"
-
-	"github.com/mattermost/mattermost/server/public/model"
-	"github.com/mattermost/mattermost/server/public/shared/mlog"
-)
-
-func (a *App) RegisterCollectionAndTopic(pluginID, collectionType, topicType string) error {
-	// we have a race condition due to multiple plugins calling this method
-	a.ch.collectionAndTopicTypesMut.Lock()
-	defer a.ch.collectionAndTopicTypesMut.Unlock()
-
-	// check if collectionType was already registered by other plugin
-	existingPluginID, ok := a.ch.collectionTypes[collectionType]
-	if ok && existingPluginID != pluginID {
-		return model.NewAppError("registerCollectionAndTopic", "app.collection.add_collection.exists.app_error", nil, "", http.StatusBadRequest)
-	}
-
-	// check if topicType was already registered to other collection
-	existingCollectionType, ok := a.ch.topicTypes[topicType]
-	if ok && existingCollectionType != collectionType {
-		return model.NewAppError("registerCollectionAndTopic", "app.collection.add_topic.exists.app_error", nil, "", http.StatusBadRequest)
-	}
-
-	a.ch.collectionTypes[collectionType] = pluginID
-	a.ch.topicTypes[topicType] = collectionType
-
-	a.ch.srv.Log().Info("registered collection and topic type", mlog.String("plugin_id", pluginID), mlog.String("collection_type", collectionType), mlog.String("topic_type", topicType))
-	return nil
-}

server/channels/app/opentracing/opentracing_layer.go

@@ -13782,28 +13782,6 @@ func (a *OpenTracingAppLayer) RegenerateTeamInviteId(teamID string) (*model.Team
 	return resultVar0, resultVar1
 }
 
-func (a *OpenTracingAppLayer) RegisterCollectionAndTopic(pluginID string, collectionType string, topicType string) error {
-	origCtx := a.ctx
-	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.RegisterCollectionAndTopic")
-
-	a.ctx = newCtx
-	a.app.Srv().Store().SetContext(newCtx)
-	defer func() {
-		a.app.Srv().Store().SetContext(origCtx)
-		a.ctx = origCtx
-	}()
-
-	defer span.Finish()
-	resultVar0 := a.app.RegisterCollectionAndTopic(pluginID, collectionType, topicType)
-
-	if resultVar0 != nil {
-		span.LogFields(spanlog.Error(resultVar0))
-		ext.Error.Set(span, true)
-	}
-
-	return resultVar0
-}
-
 func (a *OpenTracingAppLayer) RegisterPluginCommand(pluginID string, command *model.Command) error {
 	origCtx := a.ctx
 	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.RegisterPluginCommand")

server/channels/app/plugin.go

@@ -462,20 +462,6 @@ func (a *App) DisablePlugin(id string) *model.AppError {
 }
 
 func (ch *Channels) disablePlugin(id string) *model.AppError {
-	// find all collectionTypes registered by plugin
-	for collectionTypeToRemove, existingPluginId := range ch.collectionTypes {
-		if existingPluginId != id {
-			continue
-		}
-		// find all topicTypes for existing collectionType
-		for topicTypeToRemove, existingCollectionType := range ch.topicTypes {
-			if existingCollectionType == collectionTypeToRemove {
-				delete(ch.topicTypes, topicTypeToRemove)
-			}
-		}
-		delete(ch.collectionTypes, collectionTypeToRemove)
-	}
-
 	pluginsEnvironment := ch.GetPluginsEnvironment()
 	if pluginsEnvironment == nil {
 		return model.NewAppError("DisablePlugin", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)

server/channels/app/plugin_api.go

@@ -1232,10 +1232,9 @@ func (api *PluginAPI) GetCloudLimits() (*model.ProductLimits, error) {
 	return limits, err
 }
 
-// RegisterCollectionAndTopic informs the server that this plugin handles
-// the given collection and topic types.
+// RegisterCollectionAndTopic is no longer supported.
 func (api *PluginAPI) RegisterCollectionAndTopic(collectionType, topicType string) error {
-	return api.app.RegisterCollectionAndTopic(api.id, collectionType, topicType)
+	return nil
 }
 
 func (api *PluginAPI) CreateUploadSession(us *model.UploadSession) (*model.UploadSession, error) {

server/channels/app/plugin_api_test.go

@@ -2019,89 +2019,6 @@ func TestPluginAPIIsEnterpriseReady(t *testing.T) {
 	assert.Equal(t, true, api.IsEnterpriseReady())
 }
 
-func TestRegisterCollectionAndTopic(t *testing.T) {
-	os.Setenv("MM_FEATUREFLAGS_THREADSEVERYWHERE", "true")
-	defer os.Unsetenv("MM_FEATUREFLAGS_THREADSEVERYWHERE")
-	th := Setup(t)
-	defer th.TearDown()
-	th.App.UpdateConfig(func(cfg *model.Config) {
-		cfg.FeatureFlags.ThreadsEverywhere = true
-	})
-	api := th.SetupPluginAPI()
-
-	err := api.RegisterCollectionAndTopic("collection1", "topic1")
-	assert.NoError(t, err)
-	err = api.RegisterCollectionAndTopic("collection1", "topic1")
-	assert.NoError(t, err)
-	err = api.RegisterCollectionAndTopic("collection1", "topic2")
-	assert.NoError(t, err)
-	err = api.RegisterCollectionAndTopic("collection2", "topic3")
-	assert.NoError(t, err)
-	err = api.RegisterCollectionAndTopic("collection2", "topic1")
-	assert.Error(t, err)
-
-	pluginCode := `
-    package main
-
-    import (
-	  "github.com/pkg/errors"
-      "github.com/mattermost/mattermost/server/public/plugin"
-    )
-
-    type MyPlugin struct {
-      plugin.MattermostPlugin
-    }
-
-	func (p *MyPlugin) OnActivate() error {
-		if err := p.API.RegisterCollectionAndTopic("collectionTypeToBeRepeated", "some topic"); err != nil {
-			return errors.Wrap(err, "cannot register collection")
-		}
-		if err := p.API.RegisterCollectionAndTopic("some collection", "topicToBeRepeated"); err != nil {
-			return errors.Wrap(err, "cannot register collection")
-		}
-		return nil
-	}
-
-    func main() {
-      plugin.ClientMain(&MyPlugin{})
-    }
-  `
-	pluginDir, err := os.MkdirTemp("", "")
-	require.NoError(t, err)
-	webappPluginDir, err := os.MkdirTemp("", "")
-	require.NoError(t, err)
-
-	th.App.UpdateConfig(func(cfg *model.Config) {
-		*cfg.PluginSettings.Directory = pluginDir
-		*cfg.PluginSettings.ClientDirectory = webappPluginDir
-	})
-
-	newPluginAPI := func(manifest *model.Manifest) plugin.API {
-		return th.App.NewPluginAPI(th.Context, manifest)
-	}
-
-	env, err := plugin.NewEnvironment(newPluginAPI, NewDriverImpl(th.App.Srv()), pluginDir, webappPluginDir, th.App.Log(), nil)
-	require.NoError(t, err)
-
-	th.App.ch.SetPluginsEnvironment(env)
-
-	pluginID := "testplugin"
-	pluginManifest := `{"id": "testplugin", "server": {"executable": "backend.exe"}}`
-	backend := filepath.Join(pluginDir, pluginID, "backend.exe")
-	utils.CompileGo(t, pluginCode, backend)
-
-	os.WriteFile(filepath.Join(pluginDir, pluginID, "plugin.json"), []byte(pluginManifest), 0600)
-	manifest, activated, reterr := env.Activate(pluginID)
-	require.NoError(t, reterr)
-	require.NotNil(t, manifest)
-	require.True(t, activated)
-
-	err = api.RegisterCollectionAndTopic("collectionTypeToBeRepeated", "some other topic")
-	assert.Error(t, err)
-	err = api.RegisterCollectionAndTopic("some other collection", "topicToBeRepeated")
-	assert.Error(t, err)
-}
-
 func TestPluginUploadsAPI(t *testing.T) {
 	th := Setup(t).InitBasic()
 	defer th.TearDown()