PLT-5225 Added separate post types for certain system messages (#5193)

* Added separate post types for system_join_leave and system_add_remove posts

* Added username prop to channel deleted posts

* Changed slack import to properly generate the new join/leave messages

* Added username prop to channel update posts

* Moved Post(AddTo/RemoveFrom)ChanneMessage into app package

6 files changed, 119 insertions, 44 deletions

diff --git a/api/channel.go b/api/channel.go
index 474c41d07..c5ec36d4b 100644
--- a/api/channel.go
+++ b/api/channel.go
@@ -4,7 +4,6 @@
 package api
 
 import (
-	"fmt"
 	"net/http"
 	"strconv"
 	"strings"
@@ -644,7 +643,7 @@ func addMember(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	go app.PostUserAddRemoveMessage(c.Session.UserId, channel.Id, channel.TeamId, fmt.Sprintf(utils.T("api.channel.add_member.added"), nUser.Username, oUser.Username), model.POST_ADD_REMOVE)
+	go app.PostAddToChannelMessage(oUser, nUser, channel)
 
 	app.UpdateChannelLastViewedAt([]string{id}, oUser.Id)
 	w.Write([]byte(cm.ToJson()))
@@ -697,7 +696,7 @@ func removeMember(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	go app.PostUserAddRemoveMessage(c.Session.UserId, channel.Id, channel.TeamId, fmt.Sprintf(utils.T("api.channel.remove_member.removed"), user.Username), model.POST_ADD_REMOVE)
+	go app.PostRemoveFromChannelMessage(c.Session.UserId, user, channel)
 
 	result := make(map[string]string)
 	result["channel_id"] = channel.Id
diff --git a/app/channel.go b/app/channel.go
index c9199f829..818e241b7 100644
--- a/app/channel.go
+++ b/app/channel.go
@@ -91,49 +91,39 @@ func JoinDefaultChannels(teamId string, user *model.User, channelRole string) *m
 	if result := <-Srv.Store.Channel().GetByName(teamId, "town-square", true); result.Err != nil {
 		err = result.Err
 	} else {
-		cm := &model.ChannelMember{ChannelId: result.Data.(*model.Channel).Id, UserId: user.Id,
+		townSquare := result.Data.(*model.Channel)
+
+		cm := &model.ChannelMember{ChannelId: townSquare.Id, UserId: user.Id,
 			Roles: channelRole, NotifyProps: model.GetDefaultChannelNotifyProps()}
 
 		if cmResult := <-Srv.Store.Channel().SaveMember(cm); cmResult.Err != nil {
 			err = cmResult.Err
 		}
 
-		post := &model.Post{
-			ChannelId: result.Data.(*model.Channel).Id,
-			Message:   fmt.Sprintf(utils.T("api.channel.join_channel.post_and_forget"), user.Username),
-			Type:      model.POST_JOIN_LEAVE,
-			UserId:    user.Id,
+		if err := postJoinChannelMessage(user, townSquare); err != nil {
+			l4g.Error(utils.T("api.channel.post_user_add_remove_message_and_forget.error"), err)
 		}
 
 		InvalidateCacheForChannelMembers(result.Data.(*model.Channel).Id)
-
-		if _, err := CreatePost(post, teamId, false); err != nil {
-			l4g.Error(utils.T("api.channel.post_user_add_remove_message_and_forget.error"), err)
-		}
 	}
 
 	if result := <-Srv.Store.Channel().GetByName(teamId, "off-topic", true); result.Err != nil {
 		err = result.Err
 	} else {
-		cm := &model.ChannelMember{ChannelId: result.Data.(*model.Channel).Id, UserId: user.Id,
+		offTopic := result.Data.(*model.Channel)
+
+		cm := &model.ChannelMember{ChannelId: offTopic.Id, UserId: user.Id,
 			Roles: channelRole, NotifyProps: model.GetDefaultChannelNotifyProps()}
 
 		if cmResult := <-Srv.Store.Channel().SaveMember(cm); cmResult.Err != nil {
 			err = cmResult.Err
 		}
 
-		post := &model.Post{
-			ChannelId: result.Data.(*model.Channel).Id,
-			Message:   fmt.Sprintf(utils.T("api.channel.join_channel.post_and_forget"), user.Username),
-			Type:      model.POST_JOIN_LEAVE,
-			UserId:    user.Id,
+		if err := postJoinChannelMessage(user, offTopic); err != nil {
+			l4g.Error(utils.T("api.channel.post_user_add_remove_message_and_forget.error"), err)
 		}
 
 		InvalidateCacheForChannelMembers(result.Data.(*model.Channel).Id)
-
-		if _, err := CreatePost(post, teamId, false); err != nil {
-			l4g.Error(utils.T("api.channel.post_user_add_remove_message_and_forget.error"), err)
-		}
 	}
 
 	return err
@@ -276,6 +266,9 @@ func DeleteChannel(channel *model.Channel, userId string) *model.AppError {
 			Message:   fmt.Sprintf(T("api.channel.delete_channel.archived"), user.Username),
 			Type:      model.POST_CHANNEL_DELETED,
 			UserId:    userId,
+			Props: model.StringInterface{
+				"username": user.Username,
+			},
 		}
 
 		if _, err := CreatePost(post, channel.TeamId, false); err != nil {
@@ -423,6 +416,7 @@ func PostUpdateChannelHeaderMessage(userId string, channelId string, teamId stri
 			Type:      model.POST_HEADER_CHANGE,
 			UserId:    userId,
 			Props: model.StringInterface{
+				"username":   user.Username,
 				"old_header": oldChannelHeader,
 				"new_header": newChannelHeader,
 			},
@@ -459,6 +453,7 @@ func PostUpdateChannelPurposeMessage(userId string, channelId string, teamId str
 			Type:      model.POST_PURPOSE_CHANGE,
 			UserId:    userId,
 			Props: model.StringInterface{
+				"username":    user.Username,
 				"old_purpose": oldChannelPurpose,
 				"new_purpose": newChannelPurpose,
 			},
@@ -487,6 +482,7 @@ func PostUpdateChannelDisplayNameMessage(userId string, channelId string, teamId
 			Type:      model.POST_DISPLAYNAME_CHANGE,
 			UserId:    userId,
 			Props: model.StringInterface{
+				"username":        user.Username,
 				"old_displayname": oldChannelDisplayName,
 				"new_displayname": newChannelDisplayName,
 			},
@@ -588,7 +584,10 @@ func JoinChannel(channel *model.Channel, userId string) *model.AppError {
 			if _, err := AddUserToChannel(user, channel); err != nil {
 				return err
 			}
-			PostUserAddRemoveMessage(userId, channel.Id, channel.TeamId, fmt.Sprintf(utils.T("api.channel.join_channel.post_and_forget"), user.Username), model.POST_JOIN_LEAVE)
+
+			if err := postJoinChannelMessage(user, channel); err != nil {
+				return err
+			}
 		} else {
 			return model.NewLocAppError("JoinChannel", "api.channel.join_channel.permissions.app_error", nil, "")
 		}
@@ -597,6 +596,24 @@ func JoinChannel(channel *model.Channel, userId string) *model.AppError {
 	return nil
 }
 
+func postJoinChannelMessage(user *model.User, channel *model.Channel) *model.AppError {
+	post := &model.Post{
+		ChannelId: channel.Id,
+		Message:   fmt.Sprintf(utils.T("api.channel.join_channel.post_and_forget"), user.Username),
+		Type:      model.POST_JOIN_CHANNEL,
+		UserId:    user.Id,
+		Props: model.StringInterface{
+			"username": user.Username,
+		},
+	}
+
+	if _, err := CreatePost(post, channel.TeamId, false); err != nil {
+		return model.NewLocAppError("postJoinChannelMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, err.Error())
+	}
+
+	return nil
+}
+
 func LeaveChannel(channelId string, userId string) *model.AppError {
 	sc := Srv.Store.Channel().Get(channelId, true)
 	uc := Srv.Store.User().Get(userId)
@@ -629,7 +646,62 @@ func LeaveChannel(channelId string, userId string) *model.AppError {
 			return err
 		}
 
-		go PostUserAddRemoveMessage(userId, channel.Id, channel.TeamId, fmt.Sprintf(utils.T("api.channel.leave.left"), user.Username), model.POST_JOIN_LEAVE)
+		go postLeaveChannelMessage(user, channel)
+	}
+
+	return nil
+}
+
+func postLeaveChannelMessage(user *model.User, channel *model.Channel) *model.AppError {
+	post := &model.Post{
+		ChannelId: channel.Id,
+		Message:   fmt.Sprintf(utils.T("api.channel.leave.left"), user.Username),
+		Type:      model.POST_LEAVE_CHANNEL,
+		UserId:    user.Id,
+		Props: model.StringInterface{
+			"username": user.Username,
+		},
+	}
+
+	if _, err := CreatePost(post, channel.TeamId, false); err != nil {
+		return model.NewLocAppError("postLeaveChannelMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, err.Error())
+	}
+
+	return nil
+}
+
+func PostAddToChannelMessage(user *model.User, addedUser *model.User, channel *model.Channel) *model.AppError {
+	post := &model.Post{
+		ChannelId: channel.Id,
+		Message:   fmt.Sprintf(utils.T("api.channel.add_member.added"), addedUser.Username, user.Username),
+		Type:      model.POST_ADD_TO_CHANNEL,
+		UserId:    user.Id,
+		Props: model.StringInterface{
+			"username":      user.Username,
+			"addedUsername": addedUser.Username,
+		},
+	}
+
+	if _, err := CreatePost(post, channel.TeamId, false); err != nil {
+		return model.NewLocAppError("postAddToChannelMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, err.Error())
+	}
+
+	return nil
+}
+
+func PostRemoveFromChannelMessage(removerUserId string, removedUser *model.User, channel *model.Channel) *model.AppError {
+	post := &model.Post{
+		ChannelId: channel.Id,
+		Message:   fmt.Sprintf(utils.T("api.channel.remove_member.removed"), removedUser.Username),
+		Type:      model.POST_REMOVE_FROM_CHANNEL,
+		UserId:    removerUserId,
+		Props: model.StringInterface{
+			"removedUsername": removedUser.Username,
+		},
+	}
+
+	if _, err := CreatePost(post, channel.TeamId, false); err != nil {
+		return model.NewLocAppError("postRemoveFromChannelMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, err.Error())
 	}
 
 	return nil
@@ -667,20 +739,6 @@ func RemoveUserFromChannel(userIdToRemove string, removerUserId string, channel
 	return nil
 }
 
-func PostUserAddRemoveMessage(userId, channelId, teamId, message, postType string) *model.AppError {
-	post := &model.Post{
-		ChannelId: channelId,
-		Message:   message,
-		Type:      postType,
-		UserId:    userId,
-	}
-	if _, err := CreatePost(post, teamId, false); err != nil {
-		return model.NewLocAppError("PostUserAddRemoveMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, err.Error())
-	}
-
-	return nil
-}
-
 func GetNumberOfChannelsOnTeam(teamId string) (int, *model.AppError) {
 	// Get total number of channels on current team
 	if result := <-Srv.Store.Channel().GetTeamChannels(teamId); result.Err != nil {
diff --git a/app/slackimport.go b/app/slackimport.go
index 3289f140e..e4beb3d3d 100644
--- a/app/slackimport.go
+++ b/app/slackimport.go
@@ -307,12 +307,23 @@ func SlackAddPosts(teamId string, channel *model.Channel, posts []SlackPost, use
 				l4g.Debug(utils.T("api.slackimport.slack_add_posts.user_no_exists.debug"), sPost.User)
 				continue
 			}
+
+			var postType string
+			if sPost.SubType == "channel_join" {
+				postType = model.POST_JOIN_CHANNEL
+			} else {
+				postType = model.POST_LEAVE_CHANNEL
+			}
+
 			newPost := model.Post{
 				UserId:    users[sPost.User].Id,
 				ChannelId: channel.Id,
 				Message:   sPost.Text,
 				CreateAt:  SlackConvertTimeStamp(sPost.TimeStamp),
-				Type:      model.POST_JOIN_LEAVE,
+				Type:      postType,
+				Props: model.StringInterface{
+					"username": users[sPost.User].Username,
+				},
 			}
 			ImportPost(&newPost)
 		case sPost.Type == "message" && sPost.SubType == "me_message":
diff --git a/model/post.go b/model/post.go
index 668c4db61..a7729e0c4 100644
--- a/model/post.go
+++ b/model/post.go
@@ -14,8 +14,12 @@ const (
 	POST_DEFAULT               = ""
 	POST_SLACK_ATTACHMENT      = "slack_attachment"
 	POST_SYSTEM_GENERIC        = "system_generic"
-	POST_JOIN_LEAVE            = "system_join_leave"
-	POST_ADD_REMOVE            = "system_add_remove"
+	POST_JOIN_LEAVE            = "system_join_leave" // Deprecated, use POST_JOIN_CHANNEL or POST_LEAVE_CHANNEL instead
+	POST_JOIN_CHANNEL          = "system_join_channel"
+	POST_LEAVE_CHANNEL         = "system_leave_channel"
+	POST_ADD_REMOVE            = "system_add_remove" // Deprecated, use POST_ADD_TO_CHANNEL or POST_REMOVE_FROM_CHANNEL instead
+	POST_ADD_TO_CHANNEL        = "system_add_to_channel"
+	POST_REMOVE_FROM_CHANNEL   = "system_remove_from_channel"
 	POST_HEADER_CHANGE         = "system_header_change"
 	POST_DISPLAYNAME_CHANGE    = "system_displayname_change"
 	POST_PURPOSE_CHANGE        = "system_purpose_change"
@@ -121,6 +125,8 @@ func (o *Post) IsValid() *AppError {
 
 	// should be removed once more message types are supported
 	if !(o.Type == POST_DEFAULT || o.Type == POST_JOIN_LEAVE || o.Type == POST_ADD_REMOVE ||
+		o.Type == POST_JOIN_CHANNEL || o.Type == POST_LEAVE_CHANNEL ||
+		o.Type == POST_REMOVE_FROM_CHANNEL || o.Type == POST_ADD_TO_CHANNEL ||
 		o.Type == POST_SLACK_ATTACHMENT || o.Type == POST_HEADER_CHANGE || o.Type == POST_PURPOSE_CHANGE ||
 		o.Type == POST_DISPLAYNAME_CHANGE || o.Type == POST_CHANNEL_DELETED) {
 		return NewLocAppError("Post.IsValid", "model.post.is_valid.type.app_error", nil, "id="+o.Type)
diff --git a/store/sql_post_store.go b/store/sql_post_store.go
index ed87b01f7..a8fe52380 100644
--- a/store/sql_post_store.go
+++ b/store/sql_post_store.go
@@ -93,7 +93,8 @@ func (s SqlPostStore) Save(post *model.Post) StoreChannel {
 		} else {
 			time := post.UpdateAt
 
-			if post.Type != model.POST_JOIN_LEAVE && post.Type != model.POST_ADD_REMOVE {
+			if post.Type != model.POST_JOIN_LEAVE && post.Type != model.POST_JOIN_CHANNEL && post.Type != model.POST_LEAVE_CHANNEL &&
+				post.Type != model.POST_ADD_REMOVE && post.Type != model.POST_ADD_TO_CHANNEL && post.Type != model.POST_REMOVE_FROM_CHANNEL {
 				s.GetMaster().Exec("UPDATE Channels SET LastPostAt = :LastPostAt, TotalMsgCount = TotalMsgCount + 1 WHERE Id = :ChannelId", map[string]interface{}{"LastPostAt": time, "ChannelId": post.ChannelId})
 			} else {
 				// don't update TotalMsgCount for unimportant messages so that the channel isn't marked as unread
diff --git a/store/sql_post_store_test.go b/store/sql_post_store_test.go
index e3886c6bc..7416e0ab7 100644
--- a/store/sql_post_store_test.go
+++ b/store/sql_post_store_test.go
@@ -799,7 +799,7 @@ func TestPostStoreSearch(t *testing.T) {
 	o1a.ChannelId = c1.Id
 	o1a.UserId = model.NewId()
 	o1a.Message = "corey mattermost new york"
-	o1a.Type = model.POST_JOIN_LEAVE
+	o1a.Type = model.POST_JOIN_CHANNEL
 	o1a = (<-store.Post().Save(o1a)).Data.(*model.Post)
 
 	o2 := &model.Post{}