[PR-70]:Added the ability to send DMs from bot accounts

Author: Kshitij-Katiyar

README.md

@@ -31,38 +31,39 @@ Use this plugin to improve onboarding and HR processes. It adds a Welcome Bot th
 To configure the Welcome Bot, edit your `config.json` file with a message you want to send to a user in the following format:
 
 ```
-        "Plugins": {
-            "com.mattermost.welcomebot": {
-                "WelcomeMessages": [
+"Plugins": {
+    "com.mattermost.welcomebot": {
+        "WelcomeMessages": [
+            {
+                "TeamName": "your-team-name",
+                "DelayInSeconds": 3,
+                "Message": [
+                    "Your welcome message here. Each list item specifies one line in the message text."
+                ],
+                "AttachmentMessage": [
+                    "Attachment message containing user actions"
+                ],
+                "Actions" : [
                     {
-                        "TeamName": "your-team-name",
-                        "DelayInSeconds": 3,
-                        "IncludeGuests": false,
-                        "Message": [
-                            "Your welcome message here. Each list item specifies one line in the message text."
+                        "ActionType": "button",
+                        "ActionDisplayName": "User Action",
+                        "ActionName": "action-name",
+                        "ActionDirectMessagePost": "Message send to new direct messages",
+                        "ActionSuccessfulMessage": [
+                            "Message posted after the user takes this action and joins channels specified by 'ChannelsAddedTo'."
                         ],
-                        "AttachmentMessage": [
-                            "Attachment message containing user actions"
-                        ],
-                        "Actions" : [
-                            {
-                                "ActionType": "button",
-                                "ActionDisplayName": "User Action",
-                                "ActionName": "action-name",
-                                "ActionSuccessfulMessage": [
-                                    "Message posted after the user takes this action and joins channels specified by 'ChannelsAddedTo'."
-                                ],
-                                "ChannelsAddedTo": ["channel-1", "channel-2"]
-                            },
-                            {
-                                "ActionType": "automatic",
-                                "ChannelsAddedTo": ["channel-3", "channel-4"]
-                            }
-                        ]
+                        "ChannelsAddedTo": ["channel-1", "channel-2", "@example-bot"]
+                    },
+                    {
+                        "ActionType": "automatic",
+                        "ActionDirectMessagePost": "Message send to new direct messages",
+                        "ChannelsAddedTo": ["channel-3", "channel-4", "@another-bot"]
                     }
                 ]
             }
-        },
+        ]
+    }
+},
 ```
 
 where
@@ -78,6 +79,7 @@ where
     - **ActionName**: Sets the action name used by the plugin to identify which action is taken by a user.
     - **ActionSuccessfulMessage**: Message posted after the user takes this action and joins the specified channels.
     - **ChannelsAddedTo**: List of channel names the user is added to. Must be the channel handle used in the URL, in lowercase. For example, in the following URL the **channel name** value is `my-channel`: https://example.com/my-team/channels/my-channel
+    - **ActionDirectMessagePost**: The post to send users when creating the bot direct message channel
 
 The preview of the configured messages, as well as the creation of a channel welcome message, can be done via bot commands:
 * `/welcomebot help` - Displays usage information.

server/action_context.go

@@ -5,6 +5,7 @@ type ActionContext struct {
 	TeamID string `json:"team_id"`
 	UserID string `json:"user_id"`
 	Action string `json:"action"`
+	DirectMessagePost string `json:"direct_message_post"`
 }
 
 // Action type for decoding action buttons

server/configuration.go

@@ -19,6 +19,9 @@ type ConfigMessageAction struct {
 	// The message that's display after this action was successful
 	ActionSuccessfulMessage []string
 
+	// The message that is posted to direct message channels
+	ActionDirectMessagePost string
+
 	// The names of the channels that a users should be added to
 	ChannelsAddedTo []string
 }

server/welcomebot.go

@@ -109,6 +109,7 @@ func (p *Plugin) renderWelcomeMessage(messageTemplate MessageTemplate, configMes
 			action.Context = &ActionContext{}
 			action.Context.TeamID = messageTemplate.Team.Id
 			action.Context.UserID = messageTemplate.User.Id
+			action.Context.DirectMessagePost = configAction.ActionDirectMessagePost
 			action.Context.Action = "automatic"
 
 			for _, channelName := range configAction.ChannelsAddedTo {
@@ -124,6 +125,7 @@ func (p *Plugin) renderWelcomeMessage(messageTemplate MessageTemplate, configMes
 						"action":  configAction.ActionName,
 						"team_id": messageTemplate.Team.Id,
 						"user_id": messageTemplate.User.Id,
+						"direct_message_post": configAction.ActionDirectMessagePost,
 					},
 					URL: fmt.Sprintf("%v/plugins/%v/addchannels", p.getSiteURL(), manifest.ID),
 				},
@@ -228,12 +230,55 @@ func (p *Plugin) processActionMessage(messageTemplate MessageTemplate, action *A
 }
 
 func (p *Plugin) joinChannel(action *Action, channelName string) {
-	if channel, err := p.API.GetChannelByName(action.Context.TeamID, channelName, false); err == nil {
-		if _, err := p.API.AddChannelMember(channel.Id, action.Context.UserID); err != nil {
-			p.API.LogError("Couldn't add user to the channel, continuing to next channel", "user_id", action.Context.UserID, "channel_id", channel.Id)
+	// If it begins with @ create a DM channel
+	if strings.HasPrefix(channelName, "@") {
+		r := []rune(channelName)
+		dmUser, userErr := p.API.GetUserByUsername(string(r[1:]))
+	
+		if userErr != nil {
+			p.API.LogError("Couldn't find DM user, continuing to next channel", "channelName", channelName)
+			return
+		}
+
+		if !dmUser.IsBot {
+			p.API.LogError("Specified DM user is not a bot, continuing to next channel", "channelName", channelName)
+			return
+		}
+		
+		dmChannel, err := p.API.GetDirectChannel(dmUser.Id, action.Context.UserID)
+
+		if err != nil {
+			p.API.LogError("Couldn't create or get DM channel, continuing to next channel", "user_id", action.Context.UserID, "channelName", channelName, "channel_id", dmChannel.Id)
+			return
+		}
+		
+		dmMessage := "Welcome to the team!"
+		if len(action.Context.DirectMessagePost) != 0 {
+			dmMessage = action.Context.DirectMessagePost
+		}			
+
+		post := &model.Post{
+			Message:   dmMessage,
+			ChannelId: dmChannel.Id,
+			UserId:    dmUser.Id,
+		}
+
+		if _, err := p.API.CreatePost(post); err != nil {
+			p.API.LogError(
+				"Could not create direct message post",
+				"user_id", post.UserId,
+				"err", err.Error(),
+			)
+		}
+	} else { // Otherwise treat it like a normal channel
+		if channel, err := p.API.GetChannelByName(action.Context.TeamID, channelName, false); err == nil {
+			if _, err := p.API.AddChannelMember(channel.Id, action.Context.UserID); err != nil {
+				p.API.LogError("Couldn't add user to the channel, continuing to next channel", "channel_name", channelName, "user_id", action.Context.UserID, channel.Id)
+				return
+			}
+		} else {
+			p.API.LogError("failed to get channel, continuing to the next channel", "channel_name", channelName, "user_id", action.Context.UserID)
 			return
 		}
-	} else {
-		p.API.LogError("failed to get channel, continuing to the next channel", "channel_name", channelName, "user_id", action.Context.UserID)
 	}
 }