#!/usr/bin/env ruby

if File.exists?("magent.init.rb")
  require './magent.init'
elsif File.exist?("config/environments") && File.exist?("app/models") # rails
  require Dir.getwd + '/config/environment'
end

$:.unshift File.dirname(__FILE__)+"/../lib/"
require 'magent'
require 'optparse'
require 'fileutils'


def usage(option_parser, error = nil)
  $stderr.puts error if error
  $stderr.puts option_parser
  exit 1
end

options = {:piddir => "/tmp", :type => :async, :queue => :default}

optparser = OptionParser.new do |opts|
  opts.banner = "Usage: #{$0} [options] -Q <queue> <start|stop|restart>\n\nExample: magent -d -P /tmp -Q default restart\n\nOptions:"

  opts.on("-a PATH", "--agent=PATH", "Path to agent") do |o|
    options[:agent] = o
    options[:type] = :actor
  end

  opts.on("-Q QUEUE", "--queue=QUEUE", "queue to use. default=default") do |o|
    options[:queue] = o
  end

  opts.on("-t ID", "--identifier=ID", "Identifier") do |o|
    options[:identifier] = o
  end

  opts.on("-d", "--daemonize", "Run agent as a daemon") do |o|
    options[:daemonize] = true
  end

  opts.on("-l", "--log-path=PATH", "Log path") do |o|
    options[:log_path] = o
  end

  opts.on("-P", "--piddir=PATH", "PID dir to use (if daemonized)", "Default: #{options[:piddir]}") do |o|
    options[:piddir] = o
  end

  opts.on_tail("-h", "--help", "Show this help message.") do
    puts opts
    exit
  end
end

args = []
begin
  args = optparser.parse!
rescue => e
  $stderr.puts e
  $stderr.puts optparser
  exit 0
end

if args.empty?
  usage(optparser, "not enough arguments")
end

if options[:agent]
  load options[:agent]
end

class Controller
  attr_reader :options

  def initialize(opts)
    @options = opts

    @queue = @options[:queue]

    @options[:log_path] ||= Dir.getwd

    @identity = @options[:identifier] || Magent::Utils.underscore(@options[:queue].to_s)
    @identity << "-#{Socket.gethostname.split('.')[0]}"

    $stderr.puts ">> Starting magent in #{@options[:type]} model"
  end

  def start
    if @options[:daemonize] && @options[:piddir]
      run_as_daemon
    else
      Magent::Processor.new(self.channel).run!
    end
  end

  def stop
    begin
      pid = File.read(pid_file).to_i
      Process.kill("TERM", pid)
      Process.kill(0, pid)
      Process.wait
    rescue Errno::ECHILD, Errno::ESRCH => e
      $stdout.puts "Process #{pid} has stopped"
    rescue Errno::ENOENT => e
      $stdout.puts "Warning: #{e}"
    ensure
      File.unlink(pid_file) if File.exist?(pid_file)
    end
  end

  def restart
    begin
      stop
    rescue => e
      $stderr.puts "Warning: #{e}"
    end
    start
  end

  def channel
    @channel ||= (@options[:type] == :async) ? Magent::AsyncChannel.new(@queue) : Magent::ActorChannel.new(@queue)
  end

  private
  def run_as_daemon
    daemonize

    FileUtils.mkpath(@options[:piddir])
    if @options[:piddir]
      File.open(pid_file, "w") do |f|
        f.write(Process.pid)
      end
    end

    Magent::Processor.new(self.channel).run!
  end

  def pid_file
    @pid_file ||= File.join(@options[:piddir], "magent.#{@identity}.pid")
  end

  def daemonize
    exit if fork
    Process.setsid
    exit if fork

    STDIN.reopen "/dev/null"
    STDOUT.reopen "#{@options[:log_path]}/magent.#{@identity}.out", "a"
    STDERR.reopen "#{@options[:log_path]}/magent.#{@identity}.err", "a"

    STDERR.sync = true
    STDOUT.sync = true
  end
end

Controller.new(options).send(args.shift)