#!/home/ew/bin/ruby
$stdin.sync = $stdout.sync = $stderr.sync = true
require 'unicorn' # require this first to populate Unicorn::DEFAULT_START_CTX
require 'optparse'
require 'fileutils'

rails_pid = File.join(Unicorn::HttpServer::DEFAULT_START_CTX[:cwd],
                      "/tmp/pids/unicorn.pid")
cmd = File.basename($0)
daemonize = false
listeners = []
options = { :listeners => listeners }
host, port = Unicorn::Const::DEFAULT_HOST, 3000
ENV['RAILS_ENV'] ||= "development"
map_path = ENV['RAILS_RELATIVE_URL_ROOT']

opts = OptionParser.new("", 24, '  ') do |opts|
  opts.banner = "Usage: #{cmd} " \
                "[ruby options] [#{cmd} options] [rackup config file]"
  opts.separator "Ruby options:"

  lineno = 1
  opts.on("-e", "--eval LINE", "evaluate a LINE of code") do |line|
    eval line, TOPLEVEL_BINDING, "-e", lineno
    lineno += 1
  end

  opts.on("-d", "--debug", "set debugging flags (set $DEBUG to true)") do
    $DEBUG = true
  end

  opts.on("-w", "--warn", "turn warnings on for your script") do
    $-w = true
  end

  opts.on("-I", "--include PATH",
          "specify $LOAD_PATH (may be used more than once)") do |path|
    $LOAD_PATH.unshift(*path.split(/:/))
  end

  opts.on("-r", "--require LIBRARY",
          "require the library, before executing your script") do |library|
    require library
  end

  opts.separator "#{cmd} options:"

  # some of these switches exist for rackup command-line compatibility,

  opts.on("-o", "--host HOST",
          "listen on HOST (default: #{Unicorn::Const::DEFAULT_HOST})") do |h|
    host = h
  end

  opts.on("-p", "--port PORT", "use PORT (default: #{port})") do |p|
    port = p.to_i
  end

  opts.on("-E", "--env ENVIRONMENT",
          "use ENVIRONMENT for defaults (default: development)") do |e|
    ENV['RAILS_ENV'] = e
  end

  opts.on("-D", "--daemonize", "run daemonized in the background") do |d|
    daemonize = d ? true : false
  end

  # Unicorn-specific stuff
  opts.on("-l", "--listen {HOST:PORT|PATH}",
          "listen on HOST:PORT or PATH",
          "this may be specified multiple times",
          "(default: #{Unicorn::Const::DEFAULT_LISTEN})") do |address|
    listeners << address
  end

  opts.on("-c", "--config-file FILE", "Unicorn-specific config file") do |f|
    options[:config_file] = File.expand_path(f)
  end

  opts.on("-P", "--path PATH", "Runs Rails app mounted at a specific path.",
          "(default: /") do |v|
    map_path = v
  end

  # I'm avoiding Unicorn-specific config options on the command-line.
  # IMNSHO, config options on the command-line are redundant given
  # config files and make things unnecessarily complicated with multiple
  # places to look for a config option.

  opts.separator "Common options:"

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

  opts.on_tail("-v", "--version", "Show version") do
    puts " v#{Unicorn::Const::UNICORN_VERSION}"
    exit
  end

  opts.parse! ARGV
end

require 'pp' if $DEBUG

# Loads Rails and the private version of Rack it bundles. Returns a
# lambda of arity==0 that will return *another* lambda of arity==1
# suitable for using inside Rack::Builder.new block.
rails_loader = lambda do ||
  begin
    require 'config/boot'
    defined?(::RAILS_ROOT) or abort "RAILS_ROOT not defined by config/boot"
    defined?(::RAILS_ENV) or abort "RAILS_ENV not defined by config/boot"
    defined?(::Rails::VERSION::STRING) or
      abort "Rails::VERSION::STRING not defined by config/boot"
  rescue LoadError
    abort "#$0 must be run inside RAILS_ROOT (#{::RAILS_ROOT})"
  end

  if ENV['UNICORN_RAILS_USE_SYSTEM_RACK'].to_i == 0
    rails_ver = Rails::VERSION::STRING

    # maps Rails versions to the vendorized Rack version they bundle
    version_map = {
      '2.3.2' => '1.0',
      # 3.0.0 => false, # assuming 3.0.0 doesn't need vendorized Rack anymore
    }
    rack_ver = version_map[rails_ver] or
      warn "Possibly unsupported Rails version: v#{rails_ver}"

    rack_path = nil
    case rack_ver
    when String, NilClass
      version_map.values.find_all { |v| String === v }.sort.each do |v|
        $LOAD_PATH.grep(%r{/actionpack-[\d\.]+/lib/?\z}).each do |path|
          rack_path = File.join(path, "action_controller/vendor/rack-#{v}")
          File.directory?(rack_path) and break
          rack_path = nil
        end
        break if rack_path
      end
      rack_path or abort(
        "Unable to find Rails-vendorized Rack library.\n" \
        "Perhaps this script is no longer with your" \
        "Rails version (#{rails_ver}).\n")
      puts "vendorized Rack load path #{rack_path}"
      $LOAD_PATH.unshift(rack_path)
    when FalseClass
      # using non-vendorized rack library (most likely via gems)
    end
  end # Vendorized Rack LOAD_PATH finder

  # require Rack as late as possible in case $LOAD_PATH is modified
  # in config.ru or command-line
  require 'rack'

  # return the lambda
  config = ::ARGV[0] || (File.exist?('config.ru') ? 'config.ru' : nil)
  case config
  when nil
    lambda do ||
      require "#{RAILS_ROOT}/config/environment"
      ActionController::Dispatcher.new
    end
  when /\.ru$/
    raw = File.open(config, "rb") { |fp| fp.sysread(fp.stat.size) }
    # parse embedded command-line options in config.ru comments
    if raw[/^#\\(.*)/]
      opts.parse! $1.split(/\s+/)
      require 'pp' if $DEBUG
    end
    lambda { || eval("Rack::Builder.new {(#{raw}\n)}.to_app", nil, config) }
  else
    lambda do ||
      require config
      Object.const_get(File.basename(config, '.rb').capitalize)
    end
  end
end

# this won't run until after forking if preload_app is false
app = lambda do ||
  inner_app = rails_loader.call
  require 'active_support'
  require 'action_controller'
  ActionController::Base.relative_url_root = map_path if map_path
  Rack::Builder.new do
    use Rails::Rack::LogTailer unless daemonize
    use Rails::Rack::Debugger if $DEBUG
    map(map_path || '/') do
      use Rails::Rack::Static
      run inner_app.call
    end
  end.to_app
end

if listeners.empty?
  listener = "#{host}:#{port}"
  listeners << listener
end

if $DEBUG
  pp({
    :unicorn_options => options,
    :app => app,
    :daemonize => daemonize,
  })
end

# only daemonize if we're not inheriting file descriptors from our parent
if daemonize
  options[:pid] = rails_pid
  $stdin.reopen("/dev/null")
  unless ENV['UNICORN_FD']
    exit if fork
    Process.setsid
    exit if fork
  end

  # We don't do a lot of standard daemonization stuff:
  #   * $stderr/$stderr can/will be redirected separately
  #   * umask is whatever was set by the parent process at startup
  #     and can be set in config.ru and config_file, so making it
  #     0000 and potentially exposing sensitive log data can be bad
  #     policy.
  #   * Don't bother to chdir here since Unicorn is designed to
  #     run inside APP_ROOT.  Unicorn will also re-chdir() to
  #     the directory it was started in when being re-executed
  #     to pickup code changes if the original deployment directory
  #     is a symlink or otherwise got replaced.
end

# ensure Rails standard tmp paths exist
%w(cache pids sessions sockets).each do |dir|
  FileUtils.mkdir_p("tmp/#{dir}")
end
Unicorn.run(app, options)