# $Id$
# 
# Copyright (C) 2014  Dragon Research Labs ("DRL")
# Portions copyright (C) 2010--2012  Internet Systems Consortium ("ISC")
# 
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notices and this permission notice appear in all copies.
# 
# THE SOFTWARE IS PROVIDED "AS IS" AND DRL AND ISC DISCLAIM ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL DRL OR
# ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
# DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
# OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
# TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

"""
Generate IRR route and route6 objects from ROAs.
"""

import os
import socket
import sys
import argparse
import errno
import time
import rpki.x509

args = None

class route(object):
  """
  Interesting parts of a route object.
  """

  def __init__(self, label, uri, asnum, date, prefix, prefixlen, max_prefixlen):
    self.label = label
    self.uri = uri
    self.asn = asnum
    self.date = date
    self.prefix = prefix
    self.prefixlen = prefixlen
    self.max_prefixlen = self.prefixlen if max_prefixlen is None else max_prefixlen

  def __cmp__(self, other):
    result = cmp(self.asn, other.asn)
    if result == 0:
      result = cmp(self.prefix, other.prefix)
    if result == 0:
      result = cmp(self.prefixlen, other.prefixlen)
    if result == 0:
      result = cmp(self.max_prefixlen, other.max_prefixlen)
    if result == 0:
      result = cmp(self.date, other.date)
    return result

  def __str__(self):
    lines = (
      "%-14s%s/%s" % (self.label, self.prefix, self.prefixlen),
      "descr:        %s/%s-%s" % (self.prefix, self.prefixlen, self.max_prefixlen),
      "origin:       AS%d" % self.asn,
      "notify:       %s" % args.notify,
      "mnt-by:       %s" % args.mnt_by,
      "changed:      %s %s" % (args.changed_by, self.date),
      "source:       %s" % args.source,
      "override:     %s" % args.password if args.password is not None else None,
      "")
    return "\n".join(line for line in lines if line is not None)

  def write(self, output_directory):
    name = "%s-%s-%s-AS%d-%s" % (self.prefix, self.prefixlen, self.max_prefixlen, self.asn, self.date)
    with open(os.path.join(output_directory, name), "w") as f:
      f.write(str(self))


class route_list(list):
  """
  A list of route objects.
  """

  def __init__(self, rcynic_dir):
    for root, dirs, files in os.walk(rcynic_dir):
      for f in files:
        if f.endswith(".roa"):
          path = os.path.join(root, f)
          uri = "rsync://" + path[len(rcynic_dir):].lstrip("/")
          roa = rpki.x509.ROA(DER_file = path)
          roa.extract()
          assert roa.get_POW().getVersion() == 0, "ROA version is %d, expected 0" % roa.get_POW().getVersion()
          asnum = roa.get_POW().getASID()
          notBefore = roa.get_POW().certs()[0].getNotBefore().strftime("%Y%m%d")
          v4, v6 = roa.get_POW().getPrefixes()
          if v4 is not None:
            for prefix, prefixlen, max_prefixlen in v4:
              self.append(route("route:", uri, asnum, notBefore, prefix, prefixlen, max_prefixlen))
          if v6 is not None:
            for prefix, prefixlen, max_prefixlen in v6:
              self.append(route("route6:", uri, asnum, notBefore, prefix, prefixlen, max_prefixlen))
    self.sort()
    for i in xrange(len(self) - 2, -1, -1):
      if self[i] == self[i + 1]:
        del self[i + 1]

def email_header(f):
  if args.email:
    f.write("\n".join((
      "From %s" % args.email_from,
      "Date: %s" % time.strftime("%d %b %Y %T %z"),
      "From: %s" % args.email_from,
      "Subject: Fake email header to make irr_rpsl_submit happy",
      "Message-Id: <%s.%s@%s>" % (os.getpid(), time.time(), socket.gethostname()),
      "", "")))

def main():

  global args
  whoami = "%s@%s" % (os.getlogin(), socket.gethostname())

  parser = argparse.ArgumentParser(description = __doc__)
  parser.add_argument("-c", "--changed_by", default = whoami,
                      help = "override \"changed:\" value")
  parser.add_argument("-f", "--from", dest = "email_from", default = whoami,
                      help = "override \"from:\" header when using --email")
  parser.add_argument("-m", "--mnt_by", default = "MAINT-RPKI",
                      help = "override \"mnt-by:\" value")
  parser.add_argument("-n", "--notify", default = whoami,
                      help = "override \"notify:\" value")
  parser.add_argument("-p", "--password",
                      help = "specify \"override:\" password")
  parser.add_argument("-s", "--source", default = "RPKI",
                      help = "override \"source:\" value")
  group = parser.add_mutually_exclusive_group()
  group.add_argument("-e", "--email", action = "store_true",
                     help = "generate fake RFC 822 header suitable for piping to irr_rpsl_submit")
  group.add_argument("-o", "--output",
                     help = "write route and route6 objects to directory OUTPUT, one object per file")
  parser.add_argument("authenticated_directory",
                      help = "directory tree containing authenticated rcynic output")
  args = parser.parse_args()

  if not os.path.isdir(args.authenticated_directory):
    sys.exit("\"%s\" is not a directory" % args.authenticated_directory)

  routes = route_list(args.authenticated_directory)

  if args.output:
    if not os.path.isdir(args.output):
      os.makedirs(args.output)
    for r in routes:
      r.write(args.output)
  else:
    email_header(sys.stdout)
    for r in routes:
      sys.stdout.write("%s\n" % r)

if __name__ == "__main__":
  main()