#!/usr/pkg/bin/python
"""integration with Paypal shopping cart and IPN notification

   will document better as it progresses i hope...
   """

Copyright = """
    paypal_ipn - process instant payment notification from Paypal
    Copyright (C) 2004  John Comeau <jc@jcomeau.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    """
errormessage = "Not all needed libraries found, upgrade or check path"
try:
 True # not defined in older Python releases
except:
 True, False = 1, 0
try:
 import sys, os, types, re, pwd
 sys.path.append(os.sep.join([pwd.getpwuid(os.geteuid())[5], 'lib', 'python']))
 from com.jcomeau import gpl, jclicense
except:
 try:
  sys.stderr.write("%s\n" % errormessage)
 except:
  print errormessage
 raise

# get name this program was called as
self = sys.argv[0].split(os.sep)[-1]
# now get name we gave it when we wrote it
originalself = Copyright.split()[0]

# globals and routines that should be in every program
# (yes, you could import them, but there are problems in that approach too)

def DebugPrint(*whatever):
 return False # defined instead by pytest module, use that for debugging

# other globals, specific to this program

def dump_env():
 for key in os.environ.keys():
  print '%s: %s' % (key, os.environ[key])

def ipn_test():
 sys.stdout.write("Content-type: text/html\r\n\r\n") # no extra \n this way
 print "TESTING:"
 print "<PRE>"
 dump_env()
 if os.getenv('CONTENT_LENGTH') is not None:
  print "\nPOST content:\n"
  print sys.stdin.read(int(os.getenv('CONTENT_LENGTH')))
 print "</PRE>"

def paypal_ipn():
 """process instant payment notification

    made to run as CGI script, link as 'paypal_ipn.cgi'
 """
 print "Content-Type: text/html\r\n\r\n";
 print "Output from this script being emailed to site owner"
 import sys, os, re, pwd
 import cgi, urllib, urllib2
 testing = False
 #cgitb.enable() # XXX comment this out before deployment!
 homedir = pwd.getpwuid(os.geteuid())[5]
 # if can't get email addr of site, get username at least (only with suexec!)
 sysadmin = os.getenv('SITE_ADMIN') or pwd.getpwuid(os.geteuid())[0]
 sys.path.append(os.sep.join([homedir, 'lib', 'python']))
 # we had to do the above before we could import gadfly
 import gadfly
 timestamp = datetime.datetime.utcnow().isoformat(' ')[0:26]
 # now let's redirect the output
 try:
  childinput, parentoutput = os.pipe()
  pid = os.fork()
  if pid != 0:
   # parent
   os.close(childinput)
   os.dup2(parentoutput, sys.stdout.fileno())
   os.dup2(parentoutput, sys.stderr.fileno())
  else:
   # child
   os.close(parentoutput)
   os.dup2(childinput, sys.stdin.fileno())
   email = os.popen('mail -s "paypal IPN %s" %s' % (timestamp, sysadmin))
 except:
  print 'failed redirecting output: %s' % repr(sys.exc_info())
 if pid == 0: sys.exit(0) # can't exit in 'try' block without raising exception
 print "pid %d timestamp: %s" % (pid, timestamp)
 paypalCert = '/C=US/ST=California/L=Palo Alto/O=PayPal, Inc.' + \
  '/OU=Information Systems/CN=www.paypal.com'
 dbdir = os.sep.join([homedir, 'gadfly'])
 connection = gadfly.gadfly('paypal', dbdir)
 cursor = connection.cursor()
 # this query is just to get the column names
 cursor.execute("SELECT * FROM transactions WHERE txn_id = ''")
 ipn_variables = map(lambda column: column[0].lower(), cursor.description)
 # now make a dictionary with everything set to an empty string
 ipn_values = dict(map(None, ipn_variables, ('',) * len(ipn_variables)))
 # set something that's NOT dependent on PayPal's input
 ipn_values['jcomeau_com_timestamp'] = timestamp
 ipn_values['jcomeau_com_remote_addr'] = os.getenv('REMOTE_ADDR') or ''
 try:
  cursor.execute("INSERT INTO transactions %s values %s" % (
   repr(tuple(ipn_values.keys())).replace("'", ""),
   repr(tuple(ipn_values.values()))))
  connection.commit()
 except:
  print "failed inserting transaction"
  raise
 response = ['']
 try:
  if os.getenv('CONTENT_LENGTH') is not None:
   query = sys.stdin.read(int(os.getenv('CONTENT_LENGTH')))
  else:
   query = os.getenv('QUERY_STRING')
  if len(query) == 0: raise Exception, "nothing sent"
  ipn_values.update(dict(cgi.parse_qsl(query)))
  ipn_values.update({'cmd': '_notify-validate'})
  url = 'https://www.paypal.com/cgi-bin/webscr'
 except:
  dump_env() # XXX debugging
  raise # XXX debugging
  ipn_values.update({'cmd': 'wtf? empty post'})
  url = 'http://%s%s/%s' % (os.getenv('HTTP_HOST'),
   '/'.join(os.getenv('SCRIPT_NAME').split('/')[0:-1]), 'ipn_test.cgi')
 try:
  query = urllib.urlencode(ipn_values)
  request = urllib2.Request(url, query)
  urlconnection = urllib2.urlopen(request)
  #print repr(urlconnection.info().items()) # doesn't have paypal cert, damn
  response = map(lambda line: line.strip(), urlconnection.readlines())
 except:
  print 'verification failed at URL %s, values %s' % (url, repr(ipn_values))
  raise
 unexpected = filter(lambda column: column not in ipn_variables,
  ipn_values.keys())
 leftover = dict()
 for key in unexpected:
  ipn_values['jcomeau_com_ipn_leftover'] += key + ': '
  ipn_values['jcomeau_com_ipn_leftover'] += ipn_values.pop(key) + ', '
 print repr(('unexpected', unexpected)) # XXX debugging
 print "ipn_values: '%s' '%s' '%s'" % ( # XXX debugging
  ipn_values['jcomeau_com_ipn_leftover'],
  ipn_values['jcomeau_com_timestamp'],
  ipn_values['jcomeau_com_remote_addr'])
 try:
  sql = "UPDATE transactions" + \
   " SET jcomeau_com_ipn_leftover = '%s'" + \
   " WHERE jcomeau_com_timestamp = '%s'" + \
   " AND jcomeau_com_remote_addr = '%s'"
  print "sql='%s'" % sql # XXX debugging
  cursor.execute(sql % (
   ipn_values['jcomeau_com_ipn_leftover'],
   ipn_values['jcomeau_com_timestamp'],
   ipn_values['jcomeau_com_remote_addr']))
  connection.commit()
 except:
  print "failed updating unexpected data for transaction"
  raise
 print 'response: %s' % repr(response) # XXX debug
 if response[0] == 'VERIFIED' and len(response) == 1:
  # check the payment_status=Completed
  if ipn_values['payment_status'] != 'Completed':
   print 'nothing to do, payment status is %s' % ipn_values['payment_status']
   sys.exit(0)
  # check that $txn_id has not been previously processed
  items = map(lambda string: string.strip(),
   ipn_values['item_number'].split(','))
  failed = []
  for item in items:
   try:
    cursor.execute("INSERT INTO SALES (item_number, txn_id) VALUES (?, ?)",
     (item, ipn_values['txn_id']))
    connection.commit()
   except:
    failed.append(item)
  if len(failed) > 0:
   # check if txn_id for any failed items is same as ours; if so, suspicious
   # if not, probably just means someone else bought that item
   pass
  # check that receiver_email is a valid PayPal email
  cursor.execute("SELECT email_addr FROM recipient_addresses")
  emails = map(lambda email: email[0].lower(), cursor.fetchall())
  print 'emails: %s' % repr(emails) # XXX debug
  if ipn_values['receiver_email'].lower() not in emails:
   print "%s not a valid recipient address" % ipn_values['receiver_email']
   return
  # check that payment_amount/payment_currency (USD) are correct
  # process payment
  pass
 elif response[0] == 'INVALID' and len(response) == 1:
  # already logged for manual investigation
  pass
 elif response[0] == 'TESTING:':
  print "testing: %s" % repr(ipn_values)
  pass
 else:
  print 'unexpected response %s' % repr(response)
  return

if __name__ == '__main__':
 # if this program was imported by another, the above test will fail,
 # and this following code won't be used...
 routine = self.split('.')[0]
 eval('%s()' % routine)
else:
 # if you want something to be done on import, do it here; otherwise pass
 pass