require 'json'
require 'tempfile'
require 'securerandom'
require 'open3'
$stdout.sync = true

#Interactive pipe for testing.
#Creates a server that routes $stdin into if_dispatch and $stdout to int_dispatch.

class InteractiveServer
  def initialize app_js_path
    @app_js = File.read app_js_path
    inject_dispatch_shims
  end

  #Will take over any remaining IO
  def begin_pipe
    tmp = Tempfile.new(SecureRandom.hex)
    path = tmp.path
    tmp.close!
    File.write path, @app_js

    p = Open3.popen3 "boojs #{path}" do |inp, out, err, t|
      pid = t[:pid]
      begin
        loop do
          results = select([out, err, STDIN], [])
          if results[0].include? err
            err_msg = err.readline
            $stderr.puts err_msg
            #exit 1 unless err_msg =~ /[debug]/
          end

          if results[0].include? STDIN
            begin
              q = gets.strip
              if q == "RESTART"
                inp.puts "$__RESTART__"

                begin
                  #Wait for restart to respond 'ok'
                  Timeout::timeout(10) do
                    restart_res = out.readline
                    raise "Restart of phantomjs did not return '__RESTART_OK__' like expected, returned: #{restart_res.inspect}" unless restart_res == "$__RESTART_OK__\n"
                  end
                rescue Timeout::Error
                  raise "Restart of boojs did not happen within 5 seconds"
                rescue EOFError
                  #Sleep for a second to let the error pipe fill up from boojs, this error
                  #will then be displayed and then we will crash
                  sleep 3
                  $stderr.puts err.read
                  raise "boojs encountered an error"
                end

                puts "RESTART OK"
              else
                inp.puts "if_dispatch(JSON.parse('#{q}'))"
              end
            rescue Errno::EIO
              #Can't say anything here, we don't have a pipe
              exit 1
            rescue NoMethodError
              exit 1
            end
          end

          if results[0].include? out
            res = out.readline
            $stdout.puts res
            $stdout.flush
          end
        end
      ensure
        begin
          Process.kill :INT, pid
        rescue Errno::ESRCH
        end
      end
    end
  end

  #JS Functions#####################################################
  #Make calls to if_dispatch go to $stdout, make $stdin call int_dispatch
  def inject_dispatch_shims
    @app_js << %{
      function int_dispatch(q) {
        system.stdout.writeLine(JSON.stringify(q));
      }
    }
  end
  ##################################################################
end