require "insque/version"
require "redis"
require "insque/railtie" if defined?(Rails)

module Insque
  def self.debug= debug
    @debug = debug
  end

  def self.redis= redis
    @redis = redis
    @redis.select 7
  end

  def self.sender= sender
    @sender = sender
    @inbox = "insque_inbox_#{sender}"
    @processing = "insque_processing_#{sender}"
    create_send_later_handler
  end

  def self.broadcast message, params = nil, recipient = :any
    keys = []
    case recipient
    when :any
      keys = @redis.smembers 'insque_inboxes'
    when :self
      keys = [@inbox]
    else
      keys = recipient.is_a?(Array) ? recipient : [recipient]
    end
    value = { :message => "#{@sender}_#{message}", :params => params, :broadcasted_at => Time.now.utc }
    log "SENDING: #{value.to_json} TO #{keys.to_json}" if @debug
    @redis.multi do |r|
      keys.each {|k| r.lpush k, value.to_json}
    end
  end

  def self.listen worker_name=''
    @redis.sadd 'insque_inboxes', @inbox
    log "#{worker_name} START LISTENING #{@inbox}"
    loop do
      message = @redis.brpoplpush(@inbox, @processing, 0)
      log "#{worker_name} RECEIVING: #{message}" if @debug
      begin
        parsed_message = JSON.parse message
        send(parsed_message['message'], parsed_message) if self.respond_to? parsed_message['message']
      rescue => e
        log "#{worker_name} ========== BROKEN_MESSAGE: #{message} =========="
        log e.inspect
        log e.backtrace
      end
      @redis.lrem @processing, 0, message
    end
  end

  def self.janitor
    loop do
      @redis.watch @processing
      errors = []
      restart = []
      delete = []
      @redis.lrange(@processing, 0, -1).each do |m|
        begin
          parsed_message = JSON.parse(m)
          if parsed_message['restarted_at'] && DateTime.parse(parsed_message['restarted_at']) < 1.hour.ago.utc
            errors << parsed_message 
            delete << m
          elsif DateTime.parse(parsed_message['broadcasted_at']) < 1.hour.ago.utc
            restart << parsed_message.merge(:restarted_at => Time.now.utc)
            delete << m
          end
        rescue
          log "========== JANITOR_BROKEN_MESSAGE: #{m} =========="
        end
      end
      result = @redis.multi do |r|
        restart.each {|m| r.lpush @inbox, m.to_json }
        delete.each {|m| r.lrem @processing, 0, m }
      end
      if result
        errors.each {|m| log "ERROR: #{m.to_json}" }
        restart.each {|m| log "RESTART: #{m.to_json}" }
        log "CLEANING SUCCESSFULL"
      else
        log "CLEANING FAILED"
      end
      sleep(Random.rand * 10)
    end
  end

  private
  def self.log message
    print "#{Time.now.utc} #{message}\n"
    STDOUT.flush if @debug
  end

  def self.create_send_later_handler
    define_singleton_method("#{@sender}_send_later") do |msg|
      Kernel.const_get(msg['params']['class']).find(msg['params']['id']).send(msg['params']['method'], *msg['params']['args'])      
    end
  end
end

if defined?(ActiveRecord::Base)
  class ActiveRecord::Base
    def send_later(method, *args)
      Insque.broadcast :send_later, {:class => self.class.name, :id => id, :method => method, :args => args }, :self
    end
    def self.acts_as_insque_crud(*args)
      options = args.extract_options!
      excluded = (options[:exclude] || []).map(&:to_s)

      [:update, :create, :destroy].each do |action|
        set_callback action, :after do
          params = self.serializable_hash(options).delete_if {|key| (['created_at', 'updated_at'] + excluded).include? key}
          Insque.broadcast :"#{self.class.to_s.underscore}_#{action}", params
        end
      end
    end
  end
end