require 'set'
require 'securerandom'
require 'yaml'
module Plezi
  module Base
    module MessageDispatch
      class << self
        # Allows pub/sub drivers to attach to the message dispatch using `MessageDispatch.drivers << driver`
        attr_reader :drivers
      end
      @drivers = [].to_set

      module_function

      def pid
        @uuid ||= SecureRandom.urlsafe_base64.tap { |str| @prefix_len = str.length }
      end

      def _init
        @drivers.each(&:connect)
      end

      def push(message)
        # message[:type] = message[:type].name if message[:type].is_a?(Class)
        message[:origin] = pid
        hst = message.delete(:host) || Plezi.app_name
        yml = message.to_yaml
        @drivers.each { |d| d.push(hst, yml) }
      end

      def <<(msg)
        @safe_types ||= [Symbol, Date, Time, Encoding, Struct, Regexp, Range, Set].freeze
        msg = YAML.safe_load(msg, @safe_types)
        return if msg[:origin] == pid
        msg[:type] ||= msg['type'.freeze]
        msg[:type] = Object.const_get msg[:type] if msg[:type] && msg[:type] != :all
        if msg[:target] ||= msg['target'.freeze]
          Iodine::Websocket.defer(target2uuid(msg[:target])) { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[msg[:event]], *(msg[:args] ||= msg['args'.freeze] || []))) if ws._pl_ws_map[msg[:event] ||= msg['event'.freeze]] }
        elsif (msg[:type]) == :all
          Iodine::Websocket.each { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[msg[:event]], *(msg[:args] ||= msg['args'.freeze] || []))) if ws._pl_ws_map[msg[:event] ||= msg['event'.freeze]] }
        else
          Iodine::Websocket.each { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[msg[:event]], *(msg[:args] ||= msg['args'.freeze] || []))) if ws.is_a?(msg[:type]) && msg[:type]._pl_ws_map[msg[:event] ||= msg['event'.freeze]] }
        end

      rescue => e
        puts '*** The following could be a security breach attempt:', e.message, e.backtrace
        nil
      end

      def unicast(_sender, target, meth, args)
        return false if target.nil?
        if (tuuid = target2uuid)
          Iodine::Websocket.defer(tuuid) { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[meth], *args)) if ws._pl_ws_map[meth] }
          return true
        end
        push target: target, args: args, host: target2pid(target)
      end

      def broadcast(sender, meth, args)
        if sender.is_a?(Class)
          Iodine::Websocket.each { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[meth], *args)) if ws.is_a?(sender) && ws._pl_ws_map[meth] }
          push type: sender.name, args: args, event: meth
        else
          sender.each { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[meth], *args)) if ws.is_a?(sender.class) && ws._pl_ws_map[meth] }
          push type: sender.class.name, args: args, event: meth
        end
      end

      def multicast(sender, meth, args)
        if sender.is_a?(Class)
          Iodine::Websocket.each { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[meth], *args)) if ws._pl_ws_map[meth] }
          push type: :all, args: args, event: meth
        else
          sender.each { |ws| ws._pl_ad_review(ws.__send__(ws._pl_ws_map[meth], *args)) if ws._pl_ws_map[meth] }
          push type: :all, args: args, event: meth
        end
      end

      def target2uuid(target)
        return nil unless target.start_with? pid
        target[@prefix_len..-1].to_i
      end

      def target2pid(target)
        target ? target[0..(@prefix_len - 1)] : Plezi.app_name
      end
    end
  end
end
# connect default drivers
require 'plezi/websockets/redis'