#!/usr/bin/ruby

require 'rubygems'
require 'date'
require 'hpricot'
require 'open-uri'

def uris_from_status(server) 
  file = open("http://#{server}/server-status").read
  doc = Hpricot.parse(file)
  tables = doc / 'table'
  rows = (tables[0] / 'tr')[1..-1]
  data = rows.collect {|r| (r  / 'td').collect {|x| x.inner_html} }
  # filter where the PID is numeric, status is 'W' and host matches the server
  matching_data = data.select {|r| (r[1].to_i > 0) && r[3].match(/W/) && r[11].match(server)}
  # return only the URI part
  matching_data.collect {|r| r[12]}
end

CALL_TYPES = {
  :map => "Map API calls", 
  :upload => "Changeset diff uploads", 
  :amf => "AMF API calls", 
  :history => "Element history fetches", 
  :full => "Full element fetches",
  :trkpts => "GPX trackpoints calls",
  :web => "Web site traffic", 
  :other => "Other API calls"
}

def categorise_uri(line)
  uri = line.split(" ")[1]
  
  case uri
  when /api\/0\.6\/map/ then :map
  when /api\/0\.6\/changeset\/[0-9]*\/upload/ then :upload
  when /api\/0\.6\/amf/ then :amf
  when /api\/0\.6\/(node|way|relation)\/[0-9]*\/history/ then :history
  when /api\/0\.6\/(node|way|relation)\/[0-9]*\/full/ then :full
  when /api\/0\.6\/trackpoints/ then :trkpts
  when /api\/0\.6\// then :other
  else :web
  end
end

server = $0.match("api_calls_(.*)")[1]

if ARGV[0] == 'config'
  puts "graph_title Active requests"
  puts "graph_vlabel Number of requests"
  puts "graph_category api"
  CALL_TYPES.each { |k, v| puts "#{k}.label #{v}" }

else
  counts = uris_from_status(server).
      collect {|x| categorise_uri(x)}.
      inject(Hash.new) do |h, e|
    if h.has_key? e
      h[e] += 1
    else
      h[e] = 1
    end
    h
  end
  
  CALL_TYPES.keys.each do |type|
    count = counts[type] || 0
    puts "#{type}.value #{count}"
  end
end