#!/usr/bin/env python
"""
ftpsync.py - Synchronised FTP Transfer
Author: Sean B. Palmer, inamidst.com
"""

import sys, os, re, ftplib
from optparse import OptionParser

def error(msg): 
   print >> sys.stderr, 'Error:', msg
   sys.exit(1)

class FTPConf(dict): 
   r_field = re.compile(r'(?s)([^\n:]+): (.*?)(?=\n[^ \t]|\Z)')

   def __init__(self, filename=None): 
      if filename is not None: 
         self.filename = filename
      elif os.environ.has_key('FTPCONF'): 
         self.filename = os.environ.get('FTPCONF')
      else: self.filename = os.path.expanduser('~/.ftpconf')
      self.parse()

   def parse(self): 
      if not os.path.exists(self.filename): 
         error("Config file doesn't exist: %s" % self.filename)

      mode = os.stat(self.filename).st_mode
      if (mode & 070) or (mode & 07): 
         msg = "Permissions too loose for: %s (%s)"
         error(msg % (self.filename, oct(mode)))

      item = []
      f = open(self.filename)
      for line in f: 
         line = line.rstrip('\r\n')
         if line: item.append(line)
         else: 
            meta = dict(FTPConf.r_field.findall('\n'.join(item)))
            if meta.has_key('name'): 
               accountname = meta['name']
               del meta['name']
               self[accountname] = meta
            else: raise ValueError('Must include an account name')
            item = []
      f.close()

class FTP(object): 
   def __init__(self, account): 
      args = (account['host'], account['username'], account['password'])
      self.ftp = ftplib.FTP(*args)
      print 'CONNECT %s@%s' % (args[1], args[0])
      self.account = account

   def chpath(self, path): 
      remotedir = self.account['remotedir']
      localdir = self.account['localdir']
      remotepath = remotedir + path[len(localdir):]
      self.ftp.cwd(remotepath)
      print 'CWD %s' % remotepath

   def store(self, name, filename): 
      f = open(filename, 'rb')
      result = self.ftp.storbinary('STOR %s' % name, f)
      f.close()
      print 'STOR %s: %s' % (name, result)

   def chmod(self, name, newmode): 
      result = self.ftp.sendcmd('SITE CHMOD %s %s' % (newmode, name))
      print 'CHMOD %s %s: %s' % (newmode, name, result)

   def delete(self, name): 
      if raw_input('Delete %s? [y/n]: ' % name).startswith('y'): 
         result = self.ftp.delete(name)
         print 'DELETE %s: %s' % (name, result)
      else: print "Didn't delete %s" % name

def stats(filename): 
   stat = os.stat(filename)
   mode = oct(stat.st_mode)[-3:]
   return mode, stat.st_ctime, stat.st_mtime, stat.st_size

def update(datafile, newmode, newctime, newmtime, newsize): 
   fp = open(datafile, 'w')
   print >> fp, newmode, newctime, newmtime, newsize
   fp.close()

def ftpsync(account, path): 
   # zlib.adler32(...)?
   # ctime, mtime, mode, size, adlercrc
   # mode, ctime, mtime, size

   if not os.path.isdir(path): 
      error("Not a directory: %s" % path)

   datadir = os.path.join(path, '.ftpsync')
   if not os.path.isdir(datadir): 
      if os.path.exists(datadir): 
         error("Something's already here that ain't a directory: %s" % datadir)
      os.mkdir(datadir)

   ftp = FTP(account)
   ftp.chpath(path)

   for name in sorted(os.listdir(path)): 
      filename = os.path.join(path, name)
      if os.path.isfile(filename): 
         newmode, newctime, newmtime, newsize = stats(filename)
         datafile = os.path.join(datadir, name)

         if os.path.exists(datafile): 
            data = open(datafile).read()
            dataargs = data.rstrip('\r\n').split(' ')

            for i in (1, 2, 3): 
               dataargs[i] = int(dataargs[i])

            if tuple(dataargs) != (newmode, newctime, newmtime, newsize): 
               ftp.store(name, filename)
               ftp.chmod(name, newmode)
               update(datafile, newmode, newctime, newmtime, newsize)
         else: 
            ftp.store(name, filename)
            ftp.chmod(name, newmode)
            update(datafile, newmode, newctime, newmtime, newsize)

   for name in sorted(os.listdir(datadir)): 
      filename = os.path.join(path, name)
      if not os.path.exists(filename): 
         ftp.delete(name)
         os.remove(os.path.join(datadir, name))

   import socket
   try: ftp.ftp.quit()
   except socket.error: pass
   print 'QUIT'

def resolve(ftpconf, path): 
   # path must be an absolute path
   result = None
   for name in ftpconf.iterkeys(): 
      localdir = os.path.abspath(ftpconf[name]['localdir'])
      if path.startswith(localdir): 
         if (result is None) or (len(localdir) < result[1]): 
            result = (name, localdir)
   # @@ raise exception?
   if result: 
      return ftpconf[result[0]]
   else: return None

def main(argv=None): 
   ftpconf = FTPConf()

   # parser = OptionParser(usage='%prog [options] <filename>*')
   # parser.add_option("-a", "--account", dest="account", default=False, 
   #                   help="use a particular account", metavar='N')
   # options, args = parser.parse_args(argv)
   parser = OptionParser(usage='%prog <directory>')
   options, args = parser.parse_args(argv)

   # if args: 
   #    account = ftpconf[options.account or 'default']
   #    ftpsync(account, names)
   # else: parser.print_help()

   if len(args) == 1: 
      path = os.path.abspath(args[0])
      account = resolve(ftpconf, path)
      ftpsync(account, path)
   else: parser.print_help()

if __name__=="__main__": 
   main()