module Quandl
module Command
class Task

module Updatable
  
  extend ActiveSupport::Concern
  
  VERSION_URL="https://raw.github.com/quandl/quandl_command/master/lib/quandl/command/version.rb"
  
  included do
    before_execute :check_for_update_once_daily
  end
  
  def check_for_update_once_daily
    # short circuit
    return if options.production
    # onwards
    check_time = config.last_checked_for_update
    # check time present?
    if check_time.present? && check_time.is_a?(Time)
      # has it been more than one day?  
      check_for_update if Time.now - 1.day > check_time || check_time > Time.now
    else
      check_for_update
    end
  end
  
  def check_for_update
    # notify user of impending update check
    print("# Checking for updates ... ")
    # lazy load dependencies since this happens infrequently
    require_check_for_update_dependencies
    # build request
    http, request = prepare_update_request
    # send request
    response = send_update_request(http, request)
    # handle output
    handle_update_response(response)
  rescue => err
    error("An unexpected error occured while checking for updates ... #{err}")
    error err.backtrace.join("\n") if trace?
  ensure
    config.last_checked_for_update = Time.now
  end
  
  private
  
  def require_check_for_update_dependencies
    require 'uri'
    require 'net/http'
    require 'open-uri'
  end
  
  def prepare_update_request
    uri = URI.parse( VERSION_URL )
    http = Net::HTTP.new(uri.host, uri.port)
    http.use_ssl = true
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE
    [ http, Net::HTTP::Get.new(uri.request_uri) ]
  end
  
  def send_update_request(http, request)
    # send request
    response = http.request(request)
    # fetch version number
    response.body.split("\n").detect{|r| r =~ /VERSION/ }.split("'").last
  end
  
  def handle_update_response(response)
    return info(" you are up to date! #{response}") if Quandl::Command::VERSION == response
    # otherwise they are out of sync
    info(" A new version of quandl toolbelt has been released. #{response}. Please run 'quandl update'")
  end
  
end

end
end
end