#!/usr/bin/env ruby
#
# Sensu Handler: hipchat
#
# This handler script is used to send notifications to Hipchat rooms.
#
# Input:
#   @event - Event attributes.
#      @event['action'] - Property to figure out the event type i.e. whether it is create or resolve.
#      @event['check'] - Map of attributes from the check config which is calling this handler
#      @event['client'] - Map of attributes from the client config for the clients from which this event is generated.
#   option: json_config - By default, assumes the hipchat config parameters are in a file called "hipchat.json" with
#                         "hipchat" being the top-level key of the json. This command line option allows to specify
#                         a custom file instead of "hipchat.json" to fetch the hipchat config from.
#
# Output:
#    Green coloured notification on the Hipchat room if a resolve event is seen.
#    Yellow coloured notification used to notify warning if a create event is seen with a status of 1
#    Red coloured notification used to notify critical if a create event is seen with a status other than 1
#
# Note: The default hipchat config is fetched from the predefined json config file which is "hipchat.json" or any other
#       file defiend using the "json_config" command line option. The hipchat room could also be configured on a per client basis
#       by defining the "hipchat_room" attribute in the client config file. This will override the default hipchat room where the
#       alerts are being routed to for that particular client.

require 'rubygems' if RUBY_VERSION < '1.9.0'
require 'sensu-handler'
require 'hipchat'
require 'timeout'

class HipChatNotif < Sensu::Handler
  option :json_config,
         description: 'Config Name',
         short: '-j JsonConfig',
         long: '--json_config JsonConfig',
         required: false

  def event_name
    @event['client']['name'] + '/' + @event['check']['name']
  end

  def handle
    json_config = config[:json_config] || 'hipchat'
    server_url = settings[json_config]['server_url'] || 'https://api.hipchat.com'
    apiversion = settings[json_config]['apiversion'] || 'v1'
    proxy_url = settings[json_config]['proxy_url']
    hipchatmsg = HipChat::Client.new(settings[json_config]['apikey'], api_version: apiversion, http_proxy: proxy_url, server_url: server_url)
    room = @event['client']['hipchat_room'] || settings[json_config]['room']
    from = settings[json_config]['from'] || 'Sensu'

    message = @event['check']['notification'] || @event['check']['output']

    # If the playbook attribute exists and is a URL, "[<a href='url'>playbook</a>]" will be output.
    # To control the link name, set the playbook value to the HTML output you would like.
    if @event['check']['playbook']
      begin
        uri = URI.parse(@event['check']['playbook'])
        if %w( http https ).include?(uri.scheme)
          message << "  [<a href='#{@event['check']['playbook']}'>Playbook</a>]"
        else
          message << "  Playbook:  #{@event['check']['playbook']}"
        end
      rescue
        message << "  Playbook:  #{@event['check']['playbook']}"
      end
    end

    begin
      timeout(3) do
        if @event['action'].eql?('resolve')
          hipchatmsg[room].send(from, "RESOLVED - [#{event_name}] - #{message}.", color: 'green')
        else
          hipchatmsg[room].send(from, "ALERT - [#{event_name}] - #{message}.", color: @event['check']['status'] == 1 ? 'yellow' : 'red', notify: true)
        end
      end
    rescue Timeout::Error
      puts "hipchat -- timed out while attempting to message #{room}"
    end
  end
end