require_relative 'alarm/email'
require_relative 'alarm/udp2irc'
require_relative 'alarm/cfg'
require_relative 'mtr'
require_relative 'paste'
require_relative 'nodes_json'

module Ring
class SQA

  class Alarm
    def set alarm_buffer
      if @alarm == false
        @alarm = true
        msg = compose_message alarm_buffer
        Log.info msg[:short]
        @methods.each { |alarm_method| alarm_method.send msg }
      end
    end

    def clear
      if @alarm == true
        @alarm = false
        msg = { short: "#{@hostname}: clearing alarm" }
        msg[:long] = msg[:short]
        Log.info msg[:short]
        @methods.each { |alarm_method| alarm_method.send msg }
      end
    end

    private

    def initialize database
      @db       = database
      @methods  = []
      @methods  << Email.new   if CFG.email.to?
      @methods  << UDP2IRC.new if CFG.irc.password?
      @alarm    = false
      @hostname = (Socket.gethostname rescue 'anonymous')
    end

    def compose_message alarm_buffer
      exceeding_nodes = alarm_buffer.exceeding_nodes
      msg = {short: "#{@hostname}: raising alarm - #{exceeding_nodes.size} new nodes down"}
      nodes = NodesJSON.new

      nodes_list = ''
      exceeding_nodes.sort!.each do |node|
        json = nodes.get node
        nodes_list << "- %-30s %14s AS%5s %2s\n" % [json['hostname'], node, json['asn'], json['countrycode']]
      end

      mtr_list = ''
      exceeding_nodes.sample(3).each do |node|
        json = nodes.get node
        mtr_list << "%-30s AS%5s (%2s)\n" % [json['hostname'], json['asn'], json['countrycode']]
        mtr_list << MTR.run(node)
        mtr_list << "\n"
      end

      buffer_list = ''
      time = alarm_buffer.array.size-1
      alarm_buffer.array.each do |ary|
        buffer_list << "%2s min ago %3s measurements failed" % [time, ary.size/2]
        type = time.to_i < 3 ? " (raised alarm)\n" : " (baseline)\n"
        buffer_list << type
        time -= 1
      end

      msg[:long] = <<EOF
This is an automated alert from the distributed partial outage 
monitoring system "RING SQA".

At #{Time.now.utc} the following measurements were analysed 
as indicating that there is a high probability your NLNOG RING node 
cannot reach the entire internet. Possible causes could be an outage 
in your upstream's or peer's network.

The following nodes previously were reachable, but became unreachable 
over the course of the last 3 minutes:

#{nodes_list}

As a debug starting point 3 traceroutes were launched right after 
detecting the event, they might assist in pinpointing what broke:

#{mtr_list}

An alarm is raised under the following conditions: every 30 seconds 
your node pings all other nodes. The amount of nodes that cannot be 
reached is stored in a circular buffer, with each element representing 
a minute of measurements. In the event that the last three minutes are 
#{Ring::SQA::CFG.analyzer.tolerance} above the median of the previous 27 measurement slots, a partial 
outage is assumed. The ring buffer's output is as following:

#{buffer_list}

Kind regards,

NLNOG RING
EOF
      msg
    end

  end

end
end