Retrieve Gmail Thread IDs

gistfile1.rb

# Code example for http://wojt.eu/post/13496746332/retrieving-gmail-thread-ids-with-ruby

    def patch_net_imap_response_parser(klass = Net::IMAP::ResponseParser)
      klass.class_eval do
        def msg_att
          match(T_LPAR)
          attr = {}
          while true
            token = lookahead
            case token.symbol
            when T_RPAR
              shift_token
              break
            when T_SPACE
              shift_token
              token = lookahead
            end
            case token.value
            when /\A(?:ENVELOPE)\z/ni
              name, val = envelope_data
            when /\A(?:FLAGS)\z/ni
              name, val = flags_data
            when /\A(?:INTERNALDATE)\z/ni
              name, val = internaldate_data
            when /\A(?:RFC822(?:\.HEADER|\.TEXT)?)\z/ni
              name, val = rfc822_text
            when /\A(?:RFC822\.SIZE)\z/ni
              name, val = rfc822_size
            when /\A(?:BODY(?:STRUCTURE)?)\z/ni
              name, val = body_data
            when /\A(?:UID)\z/ni
              name, val = uid_data
        
            # Gmail extension additions.
            # Cargo-Cult code warning: # I have no idea why the regexp - just copying a pattern
            when /\A(?:X-GM-LABELS)\z/ni
              name, val = flags_data
            when /\A(?:X-GM-MSGID)\z/ni 
              name, vale = uid_data
            when /\A(?:X-GM-THRID)\z/ni 
              name, val = uid_data
            else
              parse_error("unknown attribute `%s'", token.value)
            end
            attr[name] = val
          end
          return attr
        end
      end
    end

    def pull_thread_ids(login,password,days)
      emails, thread_ids = nil
    
      after_date = if days.to_i > 0
        Date.today - days.to_i
      else
        nil
      end
    
      Gmail.new(login, password) do |gmail|
        #let's not tamper with global Net::IMAP and patch singleton class instead...
        patch_net_imap_response_parser gmail.imap.instance_variable_get("@parser").singleton_class

        mailbox = gmail.mailbox("[Gmail]/All Mail")
    
        query_filters = if after_date
          {:after => after_date}
        else
          {}
        end
    
        emails = mailbox.emails query_filters
    
        uids_range = emails.first.uid .. emails.last.uid
    
        response_rows = gmail.imap.uid_fetch( uids_range, "(X-GM-THRID)")
    
        thread_ids = response_rows.map {|row|
          row.attr["X-GM-THRID"].to_s(16)
        }
      end
    
      thread_ids
    end

  end