[PLT-4340] Channel Mute and "/mute" command #7617 (#7713)

* Add command and store changes to allow mute toggling

* Change channel muting to use ChannelMember notification structure

* Suppress email and push notifications for a muted channel

* Make i18n keys issue-compliant

* Add notification-cache handling for channel-muting

* Add channel handle for channel-muting slash-command

* Add unit test for mute command

* Merge branch 'master' into PLT-4340

# Conflicts:
#	app/notification.go

* Fix issue that command_mute responses will be overwritten

* Fix i18n key for channel muting

* Apply new Provider Interface to MuteCommand

* Migrate mute notification property to mark_unread

PLT-4340

* Make some i18n improvements for command_mute

PLT-4340

* Remove de.json translations

* Prevent push notifications when channel is muted

* Treat Group messages like Direct messages

* Fix unit test

* Send WS event when the channel member notify props changed

4 files changed, 128 insertions, 0 deletions

diff --git a/app/channel.go b/app/channel.go
index eadb94c2f..4e405dd93 100644
--- a/app/channel.go
+++ b/app/channel.go
@@ -482,6 +482,10 @@ func (a *App) UpdateChannelMemberNotifyProps(data map[string]string, channelId s
 	} else {
 		a.InvalidateCacheForUser(userId)
 		a.InvalidateCacheForChannelMembersNotifyProps(channelId)
+		// Notify the clients that the member notify props changed
+		evt := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_CHANNEL_MEMBER_UPDATED, "", "", userId, nil)
+		evt.Add("channelMember", member.ToJson())
+		a.Publish(evt)
 		return member, nil
 	}
 }
@@ -1481,3 +1485,16 @@ func (a *App) GetDirectChannel(userId1, userId2 string) (*model.Channel, *model.
 	}
 	return result.Data.(*model.Channel), nil
 }
+
+func (a *App) ToggleMuteChannel(channelId string, userId string) *model.ChannelMember {
+	member := (<-a.Srv.Store.Channel().GetMember(channelId, userId)).Data.(*model.ChannelMember)
+
+	if member.NotifyProps[model.MARK_UNREAD_NOTIFY_PROP] == model.CHANNEL_NOTIFY_MENTION {
+		member.NotifyProps[model.MARK_UNREAD_NOTIFY_PROP] = model.CHANNEL_MARK_UNREAD_ALL
+	} else {
+		member.NotifyProps[model.MARK_UNREAD_NOTIFY_PROP] = model.CHANNEL_NOTIFY_MENTION
+	}
+
+	a.Srv.Store.Channel().UpdateMember(member)
+	return member
+}
diff --git a/app/command_mute.go b/app/command_mute.go
new file mode 100644
index 000000000..072e79f92
--- /dev/null
+++ b/app/command_mute.go
@@ -0,0 +1,88 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"strings"
+
+	"github.com/mattermost/mattermost-server/model"
+	goi18n "github.com/nicksnyder/go-i18n/i18n"
+)
+
+type MuteProvider struct {
+}
+
+const (
+	CMD_MUTE = "mute"
+)
+
+func init() {
+	RegisterCommandProvider(&MuteProvider{})
+}
+
+func (me *MuteProvider) GetTrigger() string {
+	return CMD_MUTE
+}
+
+func (me *MuteProvider) GetCommand(a *App, T goi18n.TranslateFunc) *model.Command {
+	return &model.Command{
+		Trigger:          CMD_MUTE,
+		AutoComplete:     true,
+		AutoCompleteDesc: T("api.command_mute.desc"),
+		AutoCompleteHint: T("api.command_mute.hint"),
+		DisplayName:      T("api.command_mute.name"),
+	}
+}
+
+func (me *MuteProvider) DoCommand(a *App, args *model.CommandArgs, message string) *model.CommandResponse {
+	var channel *model.Channel
+	var noChannelErr *model.AppError
+
+	if channel, noChannelErr = a.GetChannel(args.ChannelId); noChannelErr != nil {
+		return &model.CommandResponse{Text: args.T("api.command_mute.error", map[string]interface{}{"Channel": channel.DisplayName}), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+	}
+
+	// Overwrite channel with channel-handle if set
+	if strings.HasPrefix(message, "~") {
+		splitMessage := strings.Split(message, " ")
+		chanHandle := strings.Split(splitMessage[0], "~")[1]
+		data := (<-a.Srv.Store.Channel().GetByName(channel.TeamId, chanHandle, true)).Data
+
+		if data == nil {
+			return &model.CommandResponse{Text: args.T("api.command_mute.error", map[string]interface{}{"Channel": chanHandle}), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+		}
+
+		channel = data.(*model.Channel)
+	}
+
+	channelMember := a.ToggleMuteChannel(channel.Id, args.UserId)
+
+	// Invalidate cache to allow cache lookups while sending notifications
+	a.Srv.Store.Channel().InvalidateCacheForChannelMembersNotifyProps(channel.Id)
+
+	// Direct and Group messages won't have a nice channel title, omit it
+	if channel.Type == model.CHANNEL_DIRECT || channel.Type == model.CHANNEL_GROUP {
+		if channelMember.NotifyProps[model.MARK_UNREAD_NOTIFY_PROP] == model.CHANNEL_NOTIFY_MENTION {
+			publishChannelMemberEvt(a, channelMember, args.UserId)
+			return &model.CommandResponse{Text: args.T("api.command_mute.success_mute_direct_msg"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+		} else {
+			publishChannelMemberEvt(a, channelMember, args.UserId)
+			return &model.CommandResponse{Text: args.T("api.command_mute.success_unmute_direct_msg"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+		}
+	}
+
+	if channelMember.NotifyProps[model.MARK_UNREAD_NOTIFY_PROP] == model.CHANNEL_NOTIFY_MENTION {
+		publishChannelMemberEvt(a, channelMember, args.UserId)
+		return &model.CommandResponse{Text: args.T("api.command_mute.success_mute", map[string]interface{}{"Channel": channel.DisplayName}), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+	} else {
+		publishChannelMemberEvt(a, channelMember, args.UserId)
+		return &model.CommandResponse{Text: args.T("api.command_mute.success_unmute", map[string]interface{}{"Channel": channel.DisplayName}), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+	}
+}
+
+func publishChannelMemberEvt(a *App, channelMember *model.ChannelMember, userId string) {
+	evt := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_CHANNEL_MEMBER_UPDATED, "", "", userId, nil)
+	evt.Add("channelMember", channelMember.ToJson())
+	a.Publish(evt)
+}
diff --git a/app/notification.go b/app/notification.go
index bb0c8703f..181ad4aac 100644
--- a/app/notification.go
+++ b/app/notification.go
@@ -163,6 +163,14 @@ func (a *App) SendNotifications(post *model.Post, team *model.Team, channel *mod
 				}
 			}
 
+			// Remove the user as recipient when the user has muted the channel.
+			if channelMuted, ok := channelMemberNotifyPropsMap[id][model.MARK_UNREAD_NOTIFY_PROP]; ok {
+				if channelMuted == model.CHANNEL_MARK_UNREAD_MENTION {
+					l4g.Debug("Channel muted for user_id %v, channel_mute %v", id, channelMuted)
+					userAllowsEmails = false
+				}
+			}
+
 			//If email verification is required and user email is not verified don't send email.
 			if a.Config().EmailSettings.RequireEmailVerification && !profileMap[id].EmailVerified {
 				l4g.Error("Skipped sending notification email to %v, address not verified. [details: user_id=%v]", profileMap[id].Email, id)
@@ -980,6 +988,13 @@ func DoesNotifyPropsAllowPushNotification(user *model.User, channelNotifyProps m
 	userNotify := userNotifyProps[model.PUSH_NOTIFY_PROP]
 	channelNotify, ok := channelNotifyProps[model.PUSH_NOTIFY_PROP]
 
+	// If the channel is muted do not send push notifications
+	if channelMuted, ok := channelNotifyProps[model.MARK_UNREAD_NOTIFY_PROP]; ok {
+		if channelMuted == model.CHANNEL_MARK_UNREAD_MENTION {
+			return false
+		}
+	}
+
 	if post.IsSystemMessage() {
 		return false
 	}
diff --git a/app/notification_test.go b/app/notification_test.go
index 5fc1d152c..05574eb08 100644
--- a/app/notification_test.go
+++ b/app/notification_test.go
@@ -783,6 +783,14 @@ func TestDoesNotifyPropsAllowPushNotification(t *testing.T) {
 	if DoesNotifyPropsAllowPushNotification(user, channelNotifyProps, post, true) {
 		t.Fatal("Should have returned false")
 	}
+
+	// WHEN default is ALL and channel is MUTED
+	userNotifyProps[model.PUSH_NOTIFY_PROP] = model.USER_NOTIFY_ALL
+	user.NotifyProps = userNotifyProps
+	channelNotifyProps[model.MARK_UNREAD_NOTIFY_PROP] = model.CHANNEL_MARK_UNREAD_MENTION
+	if DoesNotifyPropsAllowPushNotification(user, channelNotifyProps, post, false) {
+		t.Fatal("Should have returned false")
+	}
 }
 
 func TestDoesStatusAllowPushNotification(t *testing.T) {