require 'rubygems'
require 'set'

module Cluster::ExecBase
	@@light_cluster_initialized = false
	alias :original_start :start

	def start
		read_options
		if @options['disable_mongrel_light_cluster'] || ENV['DISABLE_MONGREL_LIGHT_CLUSTER']
			return original_start
		end

		init_light_cluster

		gem 'mongrel'
		argv = []
		argv << "start"
		argv << "-d"
		argv << "-e" << @options["environment"].to_s if @options["environment"]
		argv << "-a" << @options["address"].to_s     if @options["address"]
		argv << "-c" << @options["cwd"].to_s         if @options["cwd"]
		argv << "-t" << @options["timeout"].to_s     if @options["timeout"]
		argv << "-m" << @options["mime_map"].to_s    if @options["mime_map"]
		argv << "-r" << @options["docroot"].to_s     if @options["docroot"]
		argv << "-n" << @options["num_procs"].to_s   if @options["num_procs"]
		argv << "-B" if @options["debug"]
		argv << "-S" << @options["config_script"].to_s if @options["config_script"]
		argv << "--user" << @options["user"].to_s      if @options["user"]
		argv << "--group" << @options["group"].to_s    if @options["group"]
		argv << "--prefix" << @options["prefix"].to_s  if @options["prefix"]

		# Garbage collect stuff now so that they don't get collected
		# in the child processes (which will make pages dirty).
		ObjectSpace.garbage_collect

		@ports.each do |port|
			if @clean && pid_file_exists?(port) && !check_process(port)
				pid_file = port_pid_file(port)
				log "missing process: removing #{pid_file}"
				File.unlink(pid_file)
			end

			if pid_file_exists?(port) && check_process(port)
				log "already started port #{port}"
				next
			end

			instance_argv = argv.dup
			instance_argv << "-p" << port.to_s
			instance_argv << "-P" << port_pid_file(port)
			instance_argv << "-l" << port_log_file(port)
			log "starting port #{port}"
			log_verbose "mongrel_rails " + instance_argv.join(' ')
			exit_status, output = run_ruby_script('mongrel_rails', instance_argv)
			log_error output unless exit_status.success?
		end
	end

private
	def init_light_cluster
		return if @@light_cluster_initialized
		ENV['RAILS_ENV'] = @options['environment'] if @options['environment']
		preload_rails
		preload_app
		@@light_cluster_initialized = true
	end

	def preload_rails
		return if defined?(RAILS_ROOT)
		rails_root = @options['cwd'] || ENV['RAILS_ROOT'] || Dir.pwd
		log_verbose "Preloading Ruby on Rails"
		require "#{rails_root}/config/environment"
		require 'ruby_version_check'
		require 'initializer'
		require 'dispatcher'

		require 'breakpoint' if defined?(BREAKPOINT_SERVER_PORT)
		Dir.chdir(RAILS_ROOT)
	end

	def preload_app
		return if defined?(ApplicationController)
		preload_files = []
		include_files = glob(@options['preload'] || ['app/**/*.rb', 'lib/**/*.rb', 'vendor/plugins/*/init.rb'])
		exclude_files = Set.new(glob(@options['dont_preload'] || ''))
		include_files.each do |file|
			if !exclude_files.include?(file) && file != "app/controllers/application.rb"
				preload_files << file
			end
		end

		log_verbose 'Preloading application.rb'
		require 'application.rb'
		preload_files.each do |file|
			log_verbose "Preloading #{file}"
			expanded = File.expand_path("#{RAILS_ROOT}/#{file}").sub!(/\.rb$/, '')
			require expanded
		end
	end

	def glob(option)
		if option.is_a?(Array)
			result = []
			option.each do |pattern|
				result << Dir.glob(pattern)
			end
			return result.flatten!
		else
			return Dir.glob(option.to_s)
		end
	end

	def run_ruby_script(script, argv)
		reader, writer = IO.pipe
		pid = fork do
			ARGV.clear
			ARGV << argv
			ARGV.flatten!
			reader.close
			begin STDIN.reopen('/dev/null', 'r'); rescue; end
			begin STDOUT.reopen(writer); rescue; end
			begin STDERR.reopen(STDOUT); rescue; end
			load script
			exit
		end
		writer.close
		Process.waitpid(pid)
		output = reader.read
		reader.close
		return $?, output
	end
end