require 'celluloid/io'
require 'json'

module Hara
  class App
    include Celluloid::IO
    include Celluloid::Logger

    attr_reader :socket

    alias halt terminate

    finalizer :app_finalizer

    Actions = {}

    class << self
      def inherited klass
        ::Hara.const_set :Application, klass
      end

      def define_action action, &block
        action = action.to_s
        warn "Action #{action} duplication defined" if Actions.has_key? action
        Hara::Application.send :define_method, action, &block
        method = Hara::Application.send :instance_method, action
        Hara::Application.send :remove_method, action
        Actions[action] = method
      end
    end


    def init
    end

    #return true or false
    def authentication
      true
    end

    def authentication_failed
      halt
    end

    #after_authentication only called when authentication succeeded
    def after_authentication
    end

    def before_action action, args
    end

    def after_action action, args
    end

    def after_process
    end

    def action_missing action, args
      info " #{socket.remote_ip} request action:  #{action} args: #{args.inspect}, action not defined"
    end

    def command
      @command || {}
    end

    def on_close
    end

    private
    def initialize socket
      @socket = socket
      async.setup
    end

    def setup
      init
      info "#{socket.remote_ip} coming"
      unless authentication
        authentication_failed
      else
        after_authentication
        async.run
      end
    end

    def run
      while msg = @socket.read
        process msg
        if @closed
          terminate
          return
        end
      end
    rescue Reel::SocketError, EOFError #client disconnect
      info "#{socket.remote_ip} disconnect"
      begin
        @closed = true unless @closed
        on_close
      ensure
        terminate
      end
    end

    def process message
      @command = JSON.parse(message)
      action = @command["action"]
      args = @command["args"]
      info "#{socket.remote_ip} request action:  #{action} args: #{args.inspect}"
      before_action action, *args
      call_action action, *args
      after_action action, *args
    rescue JSON::ParserError
      info "#{socket.remote_ip} message can't parse"
      terminate
    rescue StandardError => e
      info "#{socket.remote_ip} processing error:\n#{e.inspect}"
      terminate
    ensure
      after_process
    end

    def call_action action, *args
      if Actions.has_key? action
        Actions[action].bind(self).call *args
      else
        action_missing action, *args
      end
    end

    def app_finalizer
      on_close unless @closed
    ensure
      @socket.close if @socket
    end
  end
end