Feature/allow user to unvote

plugin.json

@@ -2,7 +2,7 @@
   "id": "com.github.matterpoll.matterpoll",
   "name": "Matterpoll",
   "description": "Polling feature for Mattermost's custom slash command",
-  "version": "1.0.3",
+  "version": "1.0.3.2",
   "min_server_version": "5.6.0",
   "server": {
     "executables": {

server/plugin/api.go

@@ -20,6 +20,7 @@ const (
 
 	voteCounted = "Your vote has been counted."
 	voteUpdated = "Your vote has been updated."
+	unVote      = "Your vote has been remove."
 
 	// Parameter: Question, Permalink
 	endPollSuccessfullyFormat    = "The poll **%s** has ended and the original post have been updated. You can jump to it by pressing [here](%s)."
@@ -103,24 +104,44 @@ func (p *MatterpollPlugin) handleVote(w http.ResponseWriter, r *http.Request) {
 	}
 
 	hasVoted := poll.HasVoted(userID)
+	isUnvote := poll.DuplicatedVote(userID, optionNumber)
+
 	if err = poll.UpdateVote(userID, optionNumber); err != nil {
 		response.EphemeralText = commandGenericError
 		writePostActionIntegrationResponse(w, response)
 		return
 	}
 
+	if hasVoted {
+		if isUnvote {
+			if err = poll.Unvote(userID, optionNumber); err != nil {
+				response.EphemeralText = commandGenericError
+				writePostActionIntegrationResponse(w, response)
+				return
+			}
+		} else {
+			if err = poll.UpdateVote(userID, optionNumber); err != nil {
+				response.EphemeralText = commandGenericError
+				writePostActionIntegrationResponse(w, response)
+				return
+			}
+		}
+	}
+
 	if err = p.Store.Poll().Save(poll); err != nil {
 		response.EphemeralText = commandGenericError
 		writePostActionIntegrationResponse(w, response)
 		return
 	}
 
 	post := &model.Post{}
-	model.ParseSlackAttachment(post, poll.ToPostActions(*p.ServerConfig.ServiceSettings.SiteURL, PluginId, displayName))
+	model.ParseSlackAttachment(post, poll.ToPostActions(*p.ServerConfig.ServiceSettings.SiteURL, PluginId, displayName, p.ConvertUserIDToDisplayName))
 	response.Update = post
 
 	if hasVoted {
 		response.EphemeralText = voteUpdated
+	} else if isUnvote {
+		response.EphemeralText = unVote
 	} else {
 		response.EphemeralText = voteCounted
 	}
@@ -180,7 +201,7 @@ func (p *MatterpollPlugin) handleAddOption(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	model.ParseSlackAttachment(post, poll.ToPostActions(*p.ServerConfig.ServiceSettings.SiteURL, PluginId, displayName))
+	model.ParseSlackAttachment(post, poll.ToPostActions(*p.ServerConfig.ServiceSettings.SiteURL, PluginId, displayName, p.ConvertUserIDToDisplayName))
 	if _, appErr = p.API.UpdatePost(post); appErr != nil {
 		p.API.LogError("failed to update post", "err", appErr.Error())
 		p.SendEphemeralPost(request.ChannelId, request.UserId, commandGenericError)