# -*- coding: utf-8 -*-
require 'xmpp4r/message'

require_relative '../module_base'

module Lain
  module Modules
    class Topic < Base
      def on_message(muc, message)
        return unless /\A!topic\b/ =~ message.body

        if /\A!topic\s*(?:\ss(?:how)?.*)?\Z/ =~ message.body
          show_topic(muc, message)
        elsif /\A!topic\s+a(?:dd)?\s+(.+)\Z/ =~ message.body
          add_topic(muc, message, $~[1].strip)
        elsif /\A!topic\s+d(?:el(?:ete)?)?\s+([[:xdigit:]]+)\Z/ =~ message.body
          del_topic(muc, message, $~[1].to_i(16))
        end
      end

      def commands
        {
          '!topic [s[how]]' => 'show topics (with indices)',
          '!topic a[dd] <topic>' => 'add a topic',
          '!topic d[el[ete]] <index>' => 'remove topic <index>'
        }
      end

      private

      def current_topic(muc)
        topic = muc.subject
        return [] if topic.nil?

        topic.split('|').map { |s| s.strip }
      end

      def set_topic(muc, topic)
        muc.subject = topic.join(" | ")
      end

      def topic_list(topic)
        topic.each_with_index.map { |t, i| "[#{'%02x' % i}] #{t}" }.join("\n")
      end

      def show_topic(muc, message)
        topic = current_topic muc
        if topic.empty?
          muc.say "\nTOPIC EMPTY"
          return
        end

        muc.say("\nBEGIN TOPIC LIST\n" + topic_list(topic) + "\nEND TOPIC LIST")
      end

      def add_topic(muc, message, text)
        topic = current_topic muc
        if text.empty?
          pre = "\nERROR: No topic given."
        else
          topic.unshift text
          set_topic(muc, topic)
          pre = "\nSUCCESS"
        end

        muc.say(pre + "\n\nBEGIN TOPIC LIST\n" + topic_list(topic) + "\nEND TOPIC LIST")
      end

      def del_topic(muc, message, index)
        topic = current_topic muc
        begin
          deleted = topic.delete_at index
        rescue
          deleted = nil
        end
        if deleted.nil?
          pre = "\nERROR: Invalid index [#{'%02x' % index}]."
        else
          set_topic(muc, topic)
          pre = "\nSUCCESS"
        end

        muc.say(pre + "\n\nBEGIN TOPIC LIST\n" + topic_list(topic) + "\nEND TOPIC LIST")
      end
    end
  end
end