Add attachment support back. Originally implemented - #160

Reinstated changes from 72bbf02 that were lost during 9245376 (#160)

Author: garychapman

src/rocketchat.coffee

@@ -149,7 +149,7 @@ class RocketChatBotAdapter extends Adapter
 						edited = new Date(newmsg.editedAt.$date)
 						curts = if edited > curts then edited else curts
 					@robot.logger.info "Message receive callback id " + newmsg._id + " ts " + curts
-					@robot.logger.info "[Incoming] #{newmsg.u.username}: #{newmsg.msg}"
+					@robot.logger.info "[Incoming] #{newmsg.u.username}: #{if newmsg.file? then newmsg.attachments[0].title else newmsg.msg}"
 
 					if curts > @lastts
 						@lastts = curts
@@ -158,7 +158,25 @@ class RocketChatBotAdapter extends Adapter
 							@robot.receive new EnterMessage user, null, newmsg._id
 						else
 							user = @robot.brain.userForId newmsg.u._id, name: newmsg.u.username, room: newmsg.rid
-							message = new TextMessage user, newmsg.msg, newmsg._id
+
+							# check for the presence of attachments in the message
+							if newmsg.file? and newmsg.attachments.length
+								attachment = newmsg.attachments[0]
+
+								if attachment.image_url?
+									attachment.link = "#{RocketChatURL}#{attachment.image_url}"
+									attachment.type = 'image'
+								else if attachment.audio_url?
+									attachment.link = "#{RocketChatURL}#{attachment.audio_url}"
+									attachment.type = 'audio'
+								else if attachment.video_url?
+									attachment.link = "#{RocketChatURL}#{attachment.video_url}"
+									attachment.type = 'video'
+
+								message = new AttachmentMessage user, attachment, attachment.title, newmsg._id
+							else
+								message = new TextMessage user, newmsg.msg, newmsg._id
+								
 							startOfText = if message.text.indexOf('@') == 0 then 1 else 0
 							robotIsNamed = message.text.indexOf(@robot.name) == startOfText || message.text.indexOf(@robot.alias) == startOfText
 							if isDM and not robotIsNamed