class ImapServer
  class ClientHandler
    module Fetch
      # C: A654 FETCH 2:4 (FLAGS BODY[HEADER.FIELDS (DATE FROM)])
      # S: * 2 FETCH ....
      # S: * 3 FETCH ....
      # S: * 4 FETCH ....
      # S: A654 OK FETCH completed

      def handle_fetch(msg:, user:)
        if !(mailbox = msg.handler.selected)
          msg.respond ServerMessage.new("BAD requires to select a mailbox first",
                                        tag: msg.tag)
        end
        msg.respond ServerMessage.new("BAD require an id argument", tag: msg.tag) if !(id = msg.args.first)

        flags = msg.args[1..]
        handle_fetch_mailbox(msg, mailbox, id, flags)
      end

      # BODY[HEADER.FIELDS (MESSAGE-ID)]
      TOKENS = %w[
        ALL FAST FULL BODY ENVELOPE UID
        BODY[TEXT] RFC822 RFC822.HEADER
      ]
      def handle_fetch_mailbox(msg, mailbox, id, _flags)
        ids =
          if id.include?(":")
            Range.new id.split(":").map(&:to_i)
          elsif id.include?(",")
            id.split(",").map(&:to_i)
          else
            [id.to_i]
          end
        mails = Mail.where(mailbox: mailbox, uid: ids)
        mails.each do |mail|
          body = mail.raw
          msg.respond ServerMessage.new("#{mail.uid} FETCH (RFC822 {#{body.size}}\r\n#{body})")
        end
        msg.respond ServerMessage.new("OK FETCH completed", tag: msg.tag)
      end

    end
  end
end