require 'optparse'
require 'uri'

require 'puma/server'
require 'puma/const'
require 'puma/configuration'
require 'puma/binder'
require 'puma/detect'

require 'rack/commonlogger'
require 'rack/utils'

module Puma
  # Handles invoke a Puma::Server in a command line style.
  #
  class CLI
    # Create a new CLI object using +argv+ as the command line
    # arguments.
    #
    # +stdout+ and +stderr+ can be set to IO-like objects which
    # this object will report status on.
    #
    def initialize(argv, stdout=STDOUT, stderr=STDERR)
      @debug = false
      @argv = argv
      @stdout = stdout
      @stderr = stderr

      @workers = []

      @events = Events.new @stdout, @stderr

      @server = nil
      @status = nil

      @restart = false

      setup_options

      generate_restart_data

      @binder = Binder.new(@events)
      @binder.import_from_env
    end

    def restart_on_stop!
      @restart = true
    end

    def generate_restart_data
      # Use the same trick as unicorn, namely favor PWD because
      # it will contain an unresolved symlink, useful for when
      # the pwd is /data/releases/current.
      if dir = ENV['PWD']
        s_env = File.stat(dir)
        s_pwd = File.stat(Dir.pwd)

        if s_env.ino == s_pwd.ino and s_env.dev == s_pwd.dev
          @restart_dir = dir
        end
      end

      @restart_dir ||= Dir.pwd

      @original_argv = ARGV.dup

      if defined? Rubinius::OS_ARGV
        @restart_argv = Rubinius::OS_ARGV
      else
        require 'rubygems'

        # if $0 is a file in the current directory, then restart
        # it the same, otherwise add -S on there because it was
        # picked up in PATH.
        #
        if File.exists?($0)
          arg0 = [Gem.ruby, $0]
        else
          arg0 = [Gem.ruby, "-S", $0]
        end

        @restart_argv = arg0 + ARGV
      end
    end

    def restart!
      @options[:on_restart].each do |blk|
        blk.call self
      end

      if jruby?
        @binder.listeners.each_with_index do |(str,io),i|
          io.close

          # We have to unlink a unix socket path that's not being used
          uri = URI.parse str
          if uri.scheme == "unix"
            path = "#{uri.host}#{uri.path}"
            File.unlink path
          end
        end

        require 'puma/jruby_restart'
        JRubyRestart.chdir_exec(@restart_dir, Gem.ruby, *@restart_argv)
      else
        @binder.listeners.each_with_index do |(l,io),i|
          ENV["PUMA_INHERIT_#{i}"] = "#{io.to_i}:#{l}"
        end

        if cmd = @options[:restart_cmd]
          argv = cmd.split(' ') + @original_argv
        else
          argv = @restart_argv
        end

        Dir.chdir @restart_dir
        Kernel.exec(*argv)
      end
    end

    # Delegate +log+ to +@events+
    #
    def log(str)
      @events.log str
    end

    # Delegate +error+ to +@events+
    #
    def error(str)
      @events.error str
    end

    def debug(str)
      if @options[:debug]
        @events.log "- #{str}"
      end
    end

    def jruby?
      IS_JRUBY
    end

    def windows?
      RUBY_PLATFORM =~ /mswin32|ming32/
    end

    def unsupported(str, cond=true)
      return unless cond
      @events.error str
      raise UnsupportedOption
    end

    # Build the OptionParser object to handle the available options.
    #
    def setup_options
      @options = {
        :min_threads => 0,
        :max_threads => 16,
        :quiet => false,
        :debug => false,
        :binds => [],
        :workers => 0
      }

      @parser = OptionParser.new do |o|
        o.on "-b", "--bind URI", "URI to bind to (tcp://, unix://, ssl://)" do |arg|
          @options[:binds] << arg
        end

        o.on "-C", "--config PATH", "Load PATH as a config file" do |arg|
          @options[:config_file] = arg
        end

        o.on "-I", "--include PATH", "Specify $LOAD_PATH directories" do |arg|
          $LOAD_PATH.unshift(*arg.split(':'))
        end

        o.on "-p", "--port PORT", "Define what port TCP port to bind to",
                                  "Use -b for more advanced options" do |arg|
          @options[:binds] << "tcp://#{Configuration::DefaultTCPHost}:#{arg}"
        end

        o.on "--pidfile PATH", "Use PATH as a pidfile" do |arg|
          @options[:pidfile] = arg
        end

        o.on "-q", "--quiet", "Quiet down the output" do
          @options[:quiet] = true
        end

        o.on "--debug", "Log lowlevel debugging information" do
          @options[:debug] = true
        end

        o.on "-S", "--state PATH", "Where to store the state details" do |arg|
          @options[:state] = arg
        end

        o.on "--control URL", "The bind url to use for the control server",
                              "Use 'auto' to use temp unix server" do |arg|
          if arg
            @options[:control_url] = arg
          elsif jruby?
            unsupported "No default url available on JRuby"
          end
        end

        o.on "--control-token TOKEN",
             "The token to use as authentication for the control server" do |arg|
          @options[:control_auth_token] = arg
        end

        o.on '-t', '--threads INT', "min:max threads to use (default 0:16)" do |arg|
          min, max = arg.split(":")
          if max
            @options[:min_threads] = min.to_i
            @options[:max_threads] = max.to_i
          else
            @options[:min_threads] = 0
            @options[:max_threads] = arg.to_i
          end
        end

        o.on "-w", "--workers COUNT",
                   "Activate cluster mode: How many worker processes to create" do |arg|
          unsupported "-w not supported on JRuby and Windows",
                      jruby? || windows?

          @options[:workers] = arg.to_i
        end

        o.on "--restart-cmd CMD",
             "The puma command to run during a hot restart",
             "Default: inferred" do |cmd|
          @options[:restart_cmd] = cmd
        end

        o.on "-e", "--environment ENVIRONMENT",
             "The environment to run the Rack app on (default development)" do |arg|
          @options[:environment] = arg
        end
      end

      @parser.banner = "puma <options> <rackup file>"

      @parser.on_tail "-h", "--help", "Show help" do
        log @parser
        exit 1
      end
    end

    # If configured, write the pid of the current process out
    # to a file.
    #
    def write_pid
      if path = @options[:pidfile]
        File.open(path, "w") do |f|
          f.puts Process.pid
        end
      end
    end

    def set_rack_environment 
      # Try the user option first, then the environment variable,
      # finally default to development

      ENV['RACK_ENV'] = @options[:environment] ||
                        ENV['RACK_ENV'] ||
                        'development'
    end

    def delete_pidfile
      if path = @options[:pidfile]
        File.unlink path
      end
    end

    def write_state
      require 'yaml'

      if path = @options[:state]
        state = { "pid" => Process.pid }

        cfg = @config.dup
        cfg.options.delete :on_restart

        state["config"] = cfg

        File.open(path, "w") do |f|
          f.write state.to_yaml
        end
      end
    end

    # :nodoc:
    def parse_options
      @parser.parse! @argv

      if @argv.last
        @options[:rackup] = @argv.shift
      end

      @config = Puma::Configuration.new @options
      @config.load
    end

    def graceful_stop(server)
      log " - Gracefully stopping, waiting for requests to finish"
      server.stop(true)
      delete_pidfile
      log " - Goodbye!"
    end

    # Parse the options, load the rackup, start the server and wait
    # for it to finish.
    #
    def run
      begin
        parse_options
      rescue UnsupportedOption
        exit 1
      end

      clustered = @options[:workers] > 0

      if clustered
        @events = PidEvents.new STDOUT, STDERR
        @options[:logger] = @events
      end

      set_rack_environment

      write_pid
      write_state

      @binder.parse @options[:binds], self

      if clustered
        run_cluster
      else
        run_single
      end
    end

    def run_single
      min_t = @options[:min_threads]
      max_t = @options[:max_threads]

      server = Puma::Server.new @config.app, @events
      server.binder = @binder
      server.min_threads = min_t
      server.max_threads = max_t

      log "Puma #{Puma::Const::PUMA_VERSION} starting..."
      log "* Min threads: #{min_t}, max threads: #{max_t}"
      log "* Environment: #{ENV['RACK_ENV']}"

      @server = server

      if str = @options[:control_url]
        require 'puma/app/status'

        uri = URI.parse str

        app = Puma::App::Status.new server, self

        if token = @options[:control_auth_token]
          app.auth_token = token unless token.empty? or token == :none
        end

        status = Puma::Server.new app, @events
        status.min_threads = 0
        status.max_threads = 1

        case uri.scheme
        when "tcp"
          log "* Starting status server on #{str}"
          status.add_tcp_listener uri.host, uri.port
        when "unix"
          log "* Starting status server on #{str}"
          path = "#{uri.host}#{uri.path}"

          status.add_unix_listener path
        else
          error "Invalid status URI: #{str}"
        end

        status.run
        @status = status
      end

      begin
        Signal.trap "SIGUSR2" do
          @restart = true
          server.begin_restart
        end
      rescue Exception
        log "*** Sorry signal SIGUSR2 not implemented, restart feature disabled!"
      end

      begin
        Signal.trap "SIGTERM" do
          log " - Gracefully stopping, waiting for requests to finish"
          server.stop false
        end
      rescue Exception
        log "*** Sorry signal SIGTERM not implemented, gracefully stopping feature disabled!"
      end

      log "Use Ctrl-C to stop"

      begin
        server.run.join
      rescue Interrupt
        graceful_stop server
      end

      if @restart
        log "* Restarting..."
        @status.stop true if @status
        restart!
      end
    end

    def worker
      $0 = "puma: cluster worker: #{@master_pid}"
      Signal.trap "SIGINT", "IGNORE"

      @suicide_pipe.close

      Thread.new do
        IO.select [@check_pipe]
        log "! Detected parent died, dieing"
        exit! 1
      end

      min_t = @options[:min_threads]
      max_t = @options[:max_threads]

      server = Puma::Server.new @config.app, @events
      server.min_threads = min_t
      server.max_threads = max_t
      server.binder = @binder

      Signal.trap "SIGTERM" do
        server.stop
      end

      server.run.join
    end

    def stop_workers
      log "- Gracefully shutting down workers..."
      @workers.each { |x| x.term }

      begin
        Process.waitall
      rescue Interrupt
        log "! Cancelled waiting for workers"
      else
        log "- Goodbye!"
      end
    end

    class Worker
      def initialize(pid)
        @pid = pid
      end

      attr_reader :pid

      def term
        begin
          Process.kill "TERM", @pid
        rescue Errno::ESRCH
        end
      end
    end

    def spawn_workers
      diff = @options[:workers] - @workers.size

      diff.times do
        pid = fork { worker }
        debug "Spawned worker: #{pid}"
        @workers << Worker.new(pid)
      end
    end

    def check_workers
      while true
        pid = Process.waitpid(-1, Process::WNOHANG)
        break unless pid

        @workers.delete_if { |w| w.pid == pid }
      end

      spawn_workers
    end

    def run_cluster
      log "Puma #{Puma::Const::PUMA_VERSION} starting in cluster mode..."
      log "* Process workers: #{@options[:workers]}"
      log "* Min threads: #{@options[:min_threads]}, max threads: #{@options[:max_threads]}"
      log "* Environment: #{ENV['RACK_ENV']}"

      @master_pid = Process.pid

      read, write = IO.pipe

      Signal.trap "SIGCHLD" do
        write.write "!"
      end

      stop = false

      begin
        Signal.trap "SIGUSR2" do
          @restart = true
          stop = true
          write.write "!"
        end
      rescue Exception
      end

      begin
        Signal.trap "SIGTERM" do
          stop = true
          write.write "!"
        end
      rescue Exception
      end

      # Used by the workers to detect if the master process dies.
      # If select says that @check_pipe is ready, it's because the
      # master has exited and @suicide_pipe has been automatically
      # closed.
      #
      @check_pipe, @suicide_pipe = IO.pipe

      spawn_workers

      log "* Use Ctrl-C to stop"

      begin
        while !stop
          begin
            IO.select([read], nil, nil, 5)
            check_workers
          rescue Interrupt
            stop = true
          end
        end

        stop_workers
      ensure
        delete_pidfile
      end

      if @restart
        log "* Restarting..."
        restart!
      end
    end

    def stop
      @server.stop(true) if @server
      delete_pidfile
    end
  end
end