require 'json'

module Arsenicum
  class Task
    include Serialization

    attr_reader :target, :method, :arguments, :timestamp, :message_id, :exception

    def self.parse(raw_message, message_id)
      message_content = JSON(raw_message)

      timestamp = message_content['timestamp']
      method = message_content['method_name'].to_sym

      target = restore(message_content['target'])
      arguments = message_content['arguments'].nil? ? [] :
        message_content['arguments'].map{|arg|restore(arg)}

      new(target, method, arguments, timestamp, message_id)
    end

    def initialize(target, method, arguments, timestamp, message_id)
      @target     = target
      @method     = method
      @arguments  = arguments
      @timestamp  = timestamp
      @message_id = message_id
    end

    def prepare_serialization
      {
        target: prepare_serialization(target),
        timestamp: (Time.now.to_f * 1000000).to_i,
        method_name: method_name,
        arguments: arguments.nil? ? nil : arguments.map{|arg|prepare_serialization(arg)},
      }
    end

    def serialize
      JSON(prepare_serialization)
    end

    def execute!
      target.__send__ method, *arguments
    rescue Exception => e
      @exception = e
    end

    def successful?
      !exception
    end
  end
end