Add Product Interfaces (#20403)

* app: improve plugin interfaces

* add documentation

* improve doc

* add error id

* add more info to readme

plugin/environment.go

@@ -50,6 +50,7 @@ type PrepackagedPlugin struct {
 // of active plugins.
 type Environment struct {
 	registeredPlugins      sync.Map
+	registeredProducts     sync.Map
 	pluginHealthCheckJob   *PluginHealthCheckJob
 	logger                 *mlog.Logger
 	metrics                einterfaces.MetricsInterface
@@ -300,6 +301,14 @@ func (env *Environment) Activate(id string) (manifest *model.Manifest, activated
 	return pluginInfo.Manifest, true, nil
 }
 
+func (env *Environment) AddProduct(productID string, hooks ProductHooks) {
+	env.registeredProducts.Store(productID, newRegisteredProduct(productID, hooks))
+}
+
+func (env *Environment) RemoveProduct(productID string) {
+	env.registeredProducts.Delete(productID)
+}
+
 func (env *Environment) RemovePlugin(id string) {
 	if _, ok := env.registeredPlugins.Load(id); ok {
 		env.registeredPlugins.Delete(id)
@@ -481,6 +490,24 @@ func (env *Environment) RunMultiPluginHook(hookRunnerFunc func(hooks Hooks) bool
 		return result
 	})
 
+	env.registeredProducts.Range(func(key, value interface{}) bool {
+		rp := value.(*registeredProduct)
+
+		if !rp.Implements(hookId) {
+			return true
+		}
+
+		hookStartTime := time.Now()
+		result := hookRunnerFunc(rp.adapter)
+
+		if env.metrics != nil {
+			elapsedTime := float64(time.Since(hookStartTime)) / float64(time.Second)
+			env.metrics.ObservePluginMultiHookIterationDuration(rp.productID, elapsedTime)
+		}
+
+		return result
+	})
+
 	if env.metrics != nil {
 		elapsedTime := float64(time.Since(startTime)) / float64(time.Second)
 		env.metrics.ObservePluginMultiHookDuration(elapsedTime)

plugin/product.go

@@ -0,0 +1,147 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package plugin
+
+import (
+	"errors"
+	"io"
+	"net/http"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+)
+
+// ProductHooks is a subset of Hooks
+type ProductHooks interface {
+	OnConfigurationChange() error
+	MessageWillBePosted(ctx *Context, post *model.Post) (*model.Post, string)
+	MessageWillBeUpdated(ctx *Context, newPost, oldPost *model.Post) (*model.Post, string)
+	OnPluginClusterEvent(ctx *Context, ev model.PluginClusterEvent)
+	OnWebSocketDisconnect(webConnID, userID string)
+	OnWebSocketConnect(webConnID, userID string)
+	WebSocketMessageHasBeenPosted(webConnID, userID string, req *model.WebSocketRequest)
+}
+
+type registeredProduct struct {
+	productID   string
+	implemented map[int]struct{}
+	adapter     Hooks
+}
+
+func (rp *registeredProduct) Implements(hookId int) bool {
+	_, ok := rp.implemented[hookId]
+	return ok
+}
+
+type hooksAdapter struct {
+	productHooks ProductHooks
+}
+
+func newRegisteredProduct(pluginID string, productHooks ProductHooks) *registeredProduct {
+	return &registeredProduct{
+		productID: pluginID,
+		implemented: map[int]struct{}{
+			OnConfigurationChangeID:         {},
+			MessageWillBePostedID:           {},
+			MessageWillBeUpdatedID:          {},
+			OnPluginClusterEventID:          {},
+			OnWebSocketConnectID:            {},
+			OnWebSocketDisconnectID:         {},
+			WebSocketMessageHasBeenPostedID: {},
+		},
+		adapter: &hooksAdapter{
+			productHooks: productHooks,
+		},
+	}
+}
+
+func (a *hooksAdapter) OnActivate() error {
+	return errors.New("not implemented")
+}
+
+func (a *hooksAdapter) Implemented() ([]string, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (a *hooksAdapter) OnDeactivate() error {
+	return errors.New("not implemented")
+}
+
+func (a *hooksAdapter) OnConfigurationChange() error {
+	return a.productHooks.OnConfigurationChange()
+}
+
+func (a *hooksAdapter) ServeHTTP(c *Context, w http.ResponseWriter, r *http.Request) {}
+
+func (a *hooksAdapter) ExecuteCommand(c *Context, args *model.CommandArgs) (*model.CommandResponse, *model.AppError) {
+	return nil, model.NewAppError("ExecuteCommand", "api.command.execute_command.start.app_error", nil, "not implemented", http.StatusNotImplemented)
+}
+
+func (a *hooksAdapter) UserHasBeenCreated(c *Context, user *model.User) {}
+
+func (a *hooksAdapter) UserWillLogIn(c *Context, user *model.User) string {
+	return ""
+}
+
+func (a *hooksAdapter) UserHasLoggedIn(c *Context, user *model.User) {}
+
+func (a *hooksAdapter) MessageWillBePosted(c *Context, post *model.Post) (*model.Post, string) {
+	return a.productHooks.MessageWillBePosted(c, post)
+}
+
+func (a *hooksAdapter) MessageWillBeUpdated(c *Context, newPost, oldPost *model.Post) (*model.Post, string) {
+	return a.productHooks.MessageWillBeUpdated(c, newPost, oldPost)
+}
+
+func (a *hooksAdapter) MessageHasBeenPosted(c *Context, post *model.Post) {}
+
+func (a *hooksAdapter) MessageHasBeenUpdated(c *Context, newPost, oldPost *model.Post) {}
+
+func (a *hooksAdapter) ChannelHasBeenCreated(c *Context, channel *model.Channel) {}
+
+func (a *hooksAdapter) UserHasJoinedChannel(c *Context, channelMember *model.ChannelMember, actor *model.User) {
+}
+
+func (a *hooksAdapter) UserHasLeftChannel(c *Context, channelMember *model.ChannelMember, actor *model.User) {
+}
+
+func (a *hooksAdapter) UserHasJoinedTeam(c *Context, teamMember *model.TeamMember, actor *model.User) {
+}
+
+func (a *hooksAdapter) UserHasLeftTeam(c *Context, teamMember *model.TeamMember, actor *model.User) {}
+
+func (a *hooksAdapter) FileWillBeUploaded(c *Context, info *model.FileInfo, file io.Reader, output io.Writer) (*model.FileInfo, string) {
+	return nil, ""
+}
+
+func (a *hooksAdapter) ReactionHasBeenAdded(c *Context, reaction *model.Reaction) {}
+
+func (a *hooksAdapter) ReactionHasBeenRemoved(c *Context, reaction *model.Reaction) {}
+
+func (a *hooksAdapter) OnPluginClusterEvent(c *Context, ev model.PluginClusterEvent) {
+	a.productHooks.OnPluginClusterEvent(c, ev)
+}
+
+func (a *hooksAdapter) OnWebSocketConnect(webConnID, userID string) {
+	a.productHooks.OnWebSocketConnect(webConnID, userID)
+}
+
+func (a *hooksAdapter) OnWebSocketDisconnect(webConnID, userID string) {
+	a.productHooks.OnWebSocketDisconnect(webConnID, userID)
+}
+
+func (a *hooksAdapter) WebSocketMessageHasBeenPosted(webConnID, userID string, req *model.WebSocketRequest) {
+	a.productHooks.WebSocketMessageHasBeenPosted(webConnID, userID, req)
+}
+
+func (a *hooksAdapter) RunDataRetention(nowTime, batchSize int64) (int64, error) {
+	return -1, errors.New("not implemented")
+}
+
+func (a *hooksAdapter) OnInstall(c *Context, event model.OnInstallEvent) error {
+	return errors.New("not implemented")
+}
+
+func (a *hooksAdapter) OnSendDailyTelemetry() {}
+
+func (a *hooksAdapter) OnCloudLimitsUpdated(limits *model.ProductLimits) {}