Faster archiving methods (#234)

mailbox('[Gmail]/All Mail') can be deadly slow when you have full of emails.
This will fix that by
- create a temp folder (label)
- put the target email in it
- archive it or unarchive it
- delete the temp folder

lib/gmail/client.rb

@@ -8,6 +8,8 @@ class AuthorizationError < Net::IMAP::NoResponseError; end
     class DeliveryError < ArgumentError; end
     # Raised when given client is not registered
     class UnknownClient < ArgumentError; end
+    # Raised when email not found
+    class EmailNotFound < ArgumentError; end
 
     def self.clients
       @clients ||= {}

lib/gmail/client/base.rb

@@ -182,6 +182,23 @@ def inbox
         mailbox("INBOX")
       end
 
+      # Functionality like rails #find method
+      # https://support.google.com/mail/answer/7190?hl=en
+      # Messages with a certain message-id header
+      # Rfc822msgid:
+      # Example: rfc822msgid:200503292@example.com
+      def find(rfc822msgid)
+        message = :message_before_built
+
+        mailbox(:all) do |mailbox|
+          uid = conn.uid_search(['X-GM-RAW', "rfc822msgid:#{rfc822msgid.to_s.strip}"]).first
+          raise EmailNotFound, "Can't find message with ID #{rfc822msgid}" unless uid
+          message = Message.new(mailbox, uid)
+        end
+
+        message
+      end
+
       def mailboxes
         @mailboxes ||= {}
       end

lib/gmail/message.rb

@@ -115,24 +115,26 @@ def delete!
 
     # Archiving is done by adding the `\All Mail` label. To undo this,
     # you just re-apply the `\Inbox` label (see `#unarchive!`)
+    #
+    # IMAP's fetch('1:100', (X-GM-LABELS)) function does not fetch inbox, just emails labeled important?
+    # http://stackoverflow.com/a/28973760
+    # In my testing the currently selected mailbox is always excluded from the X-GM-LABELS results.
+    # When you called conn.select() it implicitly selected 'INBOX', therefore excluding 'Inbox'
+    # from the list of labels.
+    # If you selected a different mailbox then you would see '\\\\Inbox' in your results:
     def archive!
-      remove_label("\\Inbox")
+      @gmail.find(message.message_id).remove_label('\Inbox')
     end
 
     def unarchive!
-      add_label("\\Inbox")
+      @gmail.find(message.message_id).add_label('\Inbox')
     end
     alias_method :unspam!, :unarchive!
     alias_method :undelete!, :unarchive!
 
-    # Move to given box and delete from others.
-    # Apply a given label and optionally remove one.
-    # TODO: We should probably deprecate this method. It doesn't really add a lot
-    #       of value, especially since the concept of "moving" a message from one
-    #       label to another doesn't totally make sense in the Gmail world.
     def move_to(name, from = nil)
       add_label(name)
-      remove_label(from) if from
+      @gmail.find(message.message_id).remove_label(from) if from
     end
     alias_method :move, :move_to
     alias_method :move!, :move_to