sql-edition/servers/VendServer.py

   1 #!/usr/bin/python
   2
   3 import sys, os, string, socket, time, re
   4 from popen2 import popen2
   5 from pyPgSQL import PgSQL
   6 from LATClient import LATClient
   7 from CRC import do_crc
   8 from binascii import unhexlify
   9
  10 asynchronous_responses = [      '400', '401', # door open/closed
  11                                                         '610',        # switches changed
  12                                                  ]
  13
  14 class VendingMachine:
  15         def __init__(self, rfh, wfh):
  16                 self.secret = 'AAAAAAAAAAAAAAAA'
  17                 self.rfh = rfh
  18                 self.wfh = wfh
  19                 self.challenge = None
  20                 # Initialise ourselves into a known state
  21                 self.wfh.write('\n')
  22                 self.await_prompt()
  23                 self.wfh.write('echo off\n')
  24                 self.await_prompt()
  25                 self.wfh.write('PING\n')
  26                 code = ''
  27                 while code != '000':
  28                         (code, _) = self.get_response()
  29
  30         def await_prompt(self):
  31                 self.wfh.flush()
  32                 state = 1
  33                 prefix = ''
  34                 s = ''
  35                 while True:
  36                         s = self.rfh.read(1)
  37                         if s == '': raise Exception
  38                         if s == '\n' or s == '\r':
  39                                 state = 1
  40                                 prefix = ''
  41                         if (s == '#' or s == '%') and state == 1: state = 2
  42                         if s == ' ' and state == 2:
  43                                 if prefix == '':
  44                                         self.challenge = None
  45                                         return
  46                                 if re.search('^[0-9a-fA-F]{4}$', prefix):
  47                                         self.challenge = unhexlify(prefix)
  48                                         return
  49
  50         def get_response(self):
  51                 self.wfh.flush()
  52                 while True:
  53                         s = ''
  54                         while s == '':
  55                                 s = self.rfh.readline()
  56                                 if s == '': return None
  57                                 s = s.strip('\r\n')
  58                         code = s[0:3]
  59                         text = s[4:]
  60                         if code in asynchronous_responses:
  61                                 self.handle_event(code, text)
  62                         else:
  63                                 self.await_prompt()
  64                                 return (code, text)
  65
  66         def handle_event(self, code, text):
  67                 pass
  68
  69         def authed_message(self, message):
  70                 if self.challenge == None:
  71                         return message
  72                 crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
  73                 crc = do_crc(self.secret, crc)
  74                 crc = do_crc(message, crc)
  75                 return message+'|'+('%04x'%crc)
  76
  77         def ping(self):
  78                 self.wfh.write('PING\n')
  79                 (code, string) = self.get_response()
  80                 return (code == '000', code, string)
  81
  82         def vend(self, item):
  83                 if not re.search('^[0-9][0-9]$', item):
  84                         return (False, 'Invalid item requested (%s)'%item)
  85                 self.wfh.write(self.authed_message(('V%s\n'%item)+'\n'))
  86                 (code, string) = self.get_response()
  87                 return (code, string)
  88
  89         def beep(self, duration = None, synchronous = True):
  90                 msg = 'B'
  91                 if synchronous: msg += 'S'
  92                 if duration != None:
  93                         if duration > 255: duration = 255
  94                         if duration < 1: duration = 1
  95                         msg += '%02x'%duration
  96                 self.wfh.write(msg+'\n')
  97                 (code, string) = self.get_response()
  98                 return (code == '500', code, string)
  99
 100         def silence(self, duration = None, synchronous = True):
 101                 msg = 'C'
 102                 if synchronous: msg += 'S'
 103                 if duration != None:
 104                         if duration > 255: duration = 255
 105                         if duration < 1: duration = 1
 106                         msg += '%02x'%duration
 107                 self.wfh.write(msg+'\n')
 108                 (code, string) = self.get_response()
 109                 # FIXME: workaround a bug in rom W. should be just: return (code == '500', code, string)
 110                 return (code == '500' or code == '501', code, string)
 111
 112         def display(self, string):
 113                 if len(string) > 10:
 114                         string = string[0:10]
 115                 self.wfh.write('D'+string+'\n')
 116                 (code, string) = self.get_response()
 117                 return (code == '300', code, string)
 118
 119 if __name__ == '__main__':
 120         # Open vending machine via LAT
 121         latclient = LATClient(service = 'VEND', password = 'dmscptd')
 122         (rfh, wfh) = latclient.get_fh()
 123         v = VendingMachine(rfh, wfh)
 124         print 'PING is', v.ping()
 125         print 'BEEP is', v.beep()
 126         print 'VEND 11 is', v.vend('11')
 127         print 'SILENCE is', v.silence()
 128         print 'DISPLAY is', v.display('GOOD NIGHT')