#!/usr/bin/env ruby
#
# Copyright (C) 2010-2013  Kouhei Sutou <kou@clear-code.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#%# family=auto
#%# capabilities=autoconf

require 'rubygems'

mode = ARGV[0]

@label = ENV["label"]
@pid_file = ENV["pid_file"]
@ruby = ENV["ruby"] || Gem.ruby
passenger_spec = Gem::Specification.find_by_name("passenger")
@passenger_status = passenger_spec.bin_file("passenger-status")

def passenger_status
  if @pid_file
    unless File.readable?(@pid_file)
      return [false, "PID file isn't readable: #{@pid_file}"]
    end
    pid = File.read(@pid_file).strip
  else
    pid = nil
  end
  result = `#{@ruby} #{@passenger_status} #{pid}`
  [$?.success?, result]
end

def label_to_key(label)
  label.downcase.gsub(/[ -]+/, "_")
end

def extract_application_name(path)
  components = path.split(/\//)
  application_name, tag = components.last.split(/#/)
  application_name
end

def parse_result(result)
  sections = {}
  section = nil
  result.each_line do |line|
    case line
    when /-+\s+(.+)\s+-+/
      section = $1
      sections[section] = []
    else
      case section
      when "General information"
        case line.chomp
        when /\A(.+):\s*(\d+)\z/
          label = $1.strip
          value = $2.to_i
          key = label_to_key(label)
          sections[section] << {
            :key => key,
            :label => label,
            :value => value,
          }
        end
      when "Application groups"
        case line.chomp
        when /\A(\/.+):\s*\z/
          path = $1
          application_name = extract_application_name(path)
          sections[section] << [application_name, []]
        when /\A\s+(.+):\s*(\d+)\z/
          label = $1.strip
          value = $2.to_i
          _application_name, attributes = sections[section].last
          key = "#{_application_name}_#{label_to_key(label)}"
          label = "#{label}: #{_application_name}"
          attributes << {
            :key => key,
            :label => label,
            :value => value,
          }
        end
      end
    end
  end
  sections
end

def config
  success, result = passenger_status
  unless success
    puts result
    exit(false)
  end

  if @label
    title = "Passenger: #{@label}: status"
  else
    title = "Passenger: status"
  end
  sections = parse_result(result)
  puts(<<-EOC)
graph_title #{title}
graph_category passenger
graph_info Passenger status
graph_vlabel number of processes

EOC
  have_stack_base = false
  attributes = sections["General information"]
  sections["Application groups"].each do |_, application_attributes|
    attributes += application_attributes
  end
  attributes.each do |attribute|
    key = attribute[:key]
    next if key == "count"
    puts("#{key}.label #{attribute[:label]}")
    case key
    when /max/, /queue/
      draw = "LINE2"
    else
      if have_stack_base
        draw = "STACK"
      else
        draw = "AREA"
        have_stack_base = true
      end
    end
    puts("#{attribute[:key]}.draw #{draw}")
  end
end

def report
  success, result = passenger_status
  exit(false) unless success

  sections = parse_result(result)
  attributes = sections["General information"]
  sections["Application groups"].each do |_, application_attributes|
    attributes += application_attributes
  end
  attributes.each do |attribute|
    puts("#{attribute[:key]}.value #{attribute[:value]}")
  end
end

case mode
when "auto", "autoconf", "detect"
  success, result = passenger_status
  if success
    puts "yes"
    exit(true)
  else
    puts "no (#{result})"
    exit(false)
  end
when "config"
  config
else
  report
end