#!/usr/bin/env ruby
#
# This handler creates and resolves PagerDuty incidents, refreshing
# stale incident details every 30 minutes
#
# Copyright 2011 Sonian, Inc <chefs@sonian.net>
#
# Released under the same terms as Sensu (the MIT license); see LICENSE
# for details.
#
# Note: The sensu api token could also be configured on a per client or per check basis.
#       By defining the "pager_team" attribute in the client config file or the check config.
#       The override order will be check > client > json_config
#
# Dependencies:
#
#   sensu-plugin >= 1.0.0
#

require 'sensu-handler'
require 'pagerduty'

#
# Pagerduty
#
class PagerdutyHandler < Sensu::Handler
  option :json_config,
         description: 'Config Name',
         short: '-j JsonConfig',
         long: '--json_config JsonConfig',
         required: false,
         default: 'pagerduty'

  def incident_key
    source = @event['check']['source'] || @event['client']['name']
    incident_id = [source, @event['check']['name']].join('/')
    dedup_rules = settings[json_config]['dedup_rules'] || {}
    dedup_rules.each do |key, val|
      incident_id = incident_id.gsub(Regexp.new(key), val)
    end
    incident_id
  end

  def json_config
    @json_config ||= config[:json_config]
  end

  def api_key
    @api_key ||=
      if @event['check']['pager_team']
        settings[json_config][@event['check']['pager_team']]['api_key']
      elsif @event['client']['pager_team'] && settings[json_config][@event['client']['pager_team']].nil?
        puts "you configured your client to use a pager team of #{@event['client']['pager_team']} but it was nil, falling back to default key"
        settings[json_config]['api_key']
      elsif @event['client']['pager_team']
        settings[json_config][@event['client']['pager_team']]['api_key']
      else
        settings[json_config]['api_key']
      end
  end

  def proxy_settings
    proxy_settings = {}

    proxy_settings['proxy_host']     = settings[json_config]['proxy_host']     || nil
    proxy_settings['proxy_port']     = settings[json_config]['proxy_port']     || 3128
    proxy_settings['proxy_username'] = settings[json_config]['proxy_username'] || ''
    proxy_settings['proxy_password'] = settings[json_config]['proxy_password'] || ''

    proxy_settings
  end

  def contexts
    @contexts ||= @event['check']['pagerduty_contexts'] || []
  end

  def description_prefix
    @description_prefix = if @event['client'].key?(settings[json_config]['dynamic_description_prefix_key'])
                            "(#{@event['client'][settings[json_config]['dynamic_description_prefix_key']]})"
                          else
                            settings[json_config]['description_prefix']
                          end
  end

  def handle(pd_client = nil)
    incident_key_prefix = settings[json_config]['incident_key_prefix']
    description_prefix = description_prefix()
    proxy_settings = proxy_settings()
    begin
      tries ||= 3
      Timeout.timeout(10) do
        if proxy_settings['proxy_host']
          pagerduty = pd_client || Pagerduty.new(api_key,
                                                 proxy_host: proxy_settings['proxy_host'],
                                                 proxy_port: proxy_settings['proxy_port'],
                                                 proxy_username: proxy_settings['proxy_username'],
                                                 proxy_password: proxy_settings['proxy_password'])
        else
          pagerduty = pd_client || Pagerduty.new(api_key)
        end

        begin
          case @event['action']
          when 'create', 'flapping'
            pagerduty.trigger([description_prefix, event_summary].compact.join(' '),
                              incident_key: [incident_key_prefix, incident_key].compact.join(''),
                              details: @event,
                              contexts: contexts)
          when 'resolve'
            pagerduty.get_incident([incident_key_prefix, incident_key].compact.join('')).resolve(
              [description_prefix, event_summary].compact.join(' '), @event
            )
          end
          puts 'pagerduty -- ' + @event['action'].capitalize + 'd incident -- ' + incident_key
        rescue Net::HTTPServerException => error
          if (tries -= 1) > 0
            retry
          else
            puts 'pagerduty -- failed to ' + @event['action'] + ' incident -- ' + incident_key + ' -- ' +
                 error.response.code + ' ' + error.response.message + ': ' + error.response.body
          end
        end
      end
    rescue Timeout::Error
      if (tries -= 1) > 0
        retry
      else
        puts 'pagerduty -- timed out while attempting to ' + @event['action'] + ' a incident -- ' + incident_key
      end
    end
  end
end