# 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 notice and this permission notice appear in all copies.
# 
# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS.  IN NO EVENT SHALL 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.

"""
Iterator class to parse the output of an rcynic run.
"""

__version__ = '$Id$'

import os
import rpki.x509
import rpki.exceptions
import rpki.resource_set
from xml.etree.ElementTree import ElementTree

class UnknownObject(rpki.exceptions.RPKI_Exception):
  """
  Unrecognized object in rcynic result cache.
  """

class NotRsyncURI(rpki.exceptions.RPKI_Exception):
  """
  URI is not an rsync URI.
  """

class rcynic_object(object):
  """
  An object read from rcynic cache.
  """

  def __init__(self, filename, **kwargs):
    self.filename = filename
    for k, v in kwargs.iteritems():
      setattr(self, k, v)
    self.obj = self.obj_class(DER_file = filename)

  def __repr__(self):
    return "<%s %s %s at 0x%x>" % (self.__class__.__name__, self.uri, self.resources, id(self))

  def show_attrs(self, *attrs):
    """
    Print a bunch of object attributes, quietly ignoring any that
    might be missing.
    """
    for a in attrs:
      try:
        print "%s: %s" % (a.capitalize(), getattr(self, a))
      except AttributeError:
        pass

  def show(self):
    """
    Print common object attributes.
    """
    self.show_attrs("filename", "uri", "status", "timestamp")

class rcynic_certificate(rcynic_object):
  """
  A certificate from rcynic cache.
  """

  obj_class = rpki.x509.X509

  def __init__(self, filename, **kwargs):
    rcynic_object.__init__(self, filename, **kwargs)
    self.notBefore = self.obj.getNotBefore()
    self.notAfter =  self.obj.getNotAfter()
    self.aia_uri = self.obj.get_aia_uri()
    self.sia_directory_uri = self.obj.get_sia_directory_uri()
    self.manifest_uri = self.obj.get_sia_manifest_uri()
    self.resources = self.obj.get_3779resources()
    self.is_ca = self.obj.is_CA()
    self.serial = self.obj.getSerial()
    self.issuer = self.obj.getIssuer()
    self.subject = self.obj.getSubject()
    self.ski = self.obj.hSKI()
    self.aki = self.obj.hAKI()

  def show(self):
    """
    Print certificate attributes.
    """
    rcynic_object.show(self)
    self.show_attrs("notBefore", "notAfter", "aia_uri", "sia_directory_uri", "resources")

class rcynic_roa(rcynic_object):
  """
  A ROA from rcynic cache.
  """

  obj_class = rpki.x509.ROA

  def __init__(self, filename, **kwargs):
    rcynic_object.__init__(self, filename, **kwargs)
    self.obj.extract()
    self.asID = self.obj.get_POW().getASID()
    self.prefix_sets = []
    v4, v6 = self.obj.get_POW().getPrefixes()
    if v4:
      self.prefix_sets.append(rpki.resource_set.roa_prefix_set_ipv4([
        rpki.resource_set.roa_prefix_ipv4(p[0], p[1], p[2]) for p in v4]))
    if v6:
      self.prefix_sets.append(rpki.resource_set.roa_prefix_set_ipv6([
        rpki.resource_set.roa_prefix_ipv6(p[0], p[1], p[2]) for p in v6]))
    self.ee = rpki.x509.X509(POW = self.obj.get_POW().certs()[0])
    self.notBefore = self.ee.getNotBefore()
    self.notAfter = self.ee.getNotAfter()
    self.aia_uri = self.ee.get_aia_uri()
    self.resources = self.ee.get_3779resources()
    self.issuer = self.ee.getIssuer()
    self.serial = self.ee.getSerial()
    self.subject = self.ee.getSubject()
    self.aki = self.ee.hAKI()
    self.ski = self.ee.hSKI()

  def show(self):
    """
    Print ROA attributes.
    """
    rcynic_object.show(self)
    self.show_attrs("notBefore", "notAfter", "aia_uri", "resources", "asID")
    if self.prefix_sets:
      print "Prefixes:", ",".join(str(i) for i in self.prefix_sets)

class rcynic_ghostbuster(rcynic_object):
  """
  Ghostbuster record from the rcynic cache.
  """

  obj_class = rpki.x509.Ghostbuster

  def __init__(self, *args, **kwargs):
    rcynic_object.__init__(self, *args, **kwargs)
    self.obj.extract()
    self.vcard = self.obj.get_content()
    self.ee = rpki.x509.X509(POW = self.obj.get_POW().certs()[0])
    self.notBefore = self.ee.getNotBefore()
    self.notAfter = self.ee.getNotAfter()
    self.aia_uri = self.ee.get_aia_uri()
    self.issuer = self.ee.getIssuer()
    self.serial = self.ee.getSerial()
    self.subject = self.ee.getSubject()
    self.aki = self.ee.hAKI()
    self.ski = self.ee.hSKI()

  def show(self):
    rcynic_object.show(self)
    self.show_attrs("notBefore", "notAfter", "vcard")

file_name_classes = {
  ".cer" : rcynic_certificate,
  ".gbr" : rcynic_ghostbuster,
  ".roa" : rcynic_roa }

class rcynic_file_iterator(object):
  """
  Iterate over files in an rcynic output tree, yielding a Python
  representation of each object found.
  """

  def __init__(self, rcynic_root,
               authenticated_subdir = "authenticated"):
    self.rcynic_dir = os.path.join(rcynic_root, authenticated_subdir)

  def __iter__(self):
    for root, dirs, files in os.walk(self.rcynic_dir): # pylint: disable=W0612
      for filename in files:
        filename = os.path.join(root, filename)
        ext = os.path.splitext(filename)[1]
        if ext in file_name_classes:
          yield file_name_classes[ext](filename)

class validation_status_element(object):
  def __init__(self, *args, **kwargs):
    self.attrs = []
    for k, v in kwargs.iteritems():
      setattr(self, k, v)
      # attribute names are saved so that the __repr__ method can
      # display the subset of attributes the user specified
      self.attrs.append(k)
    self._obj = None

  def get_obj(self):
    if not self._obj:
      self._obj = self.file_class(filename=self.filename, uri=self.uri)
    return self._obj

  def __repr__(self):
    v = [self.__class__.__name__, 'id=%s' % str(id(self))]
    v.extend(['%s=%s' % (x, getattr(self, x)) for x in self.attrs])
    return '<%s>' % (' '.join(v),)

  obj = property(get_obj)

class rcynic_xml_iterator(object):
  """
  Iterate over validation_status entries in the XML output from an
  rcynic run.  Yields a tuple for each entry:

    timestamp, generation, status, object

  where URI, status, and timestamp are the corresponding values from
  the XML element, OK is a boolean indicating whether validation was
  considered succesful, and object is a Python representation of the
  object in question.  If OK is True, object will be from rcynic's
  authenticated output tree; otherwise, object will be from rcynic's
  unauthenticated output tree.

  Note that it is possible for the same URI to appear in more than one
  validation_status element; in such cases, the succesful case (OK
  True) should be the last entry (as rcynic will stop trying once it
  gets a good copy), but there may be multiple failures, which might
  or might not have different status codes.
  """

  def __init__(self, rcynic_root, xml_file,
               authenticated_old_subdir = "authenticated.old",
               unauthenticated_subdir = "unauthenticated"):
    self.rcynic_root = rcynic_root
    self.xml_file = xml_file
    self.authenticated_subdir = os.path.join(rcynic_root, 'authenticated')
    self.authenticated_old_subdir = os.path.join(rcynic_root, authenticated_old_subdir)
    self.unauthenticated_subdir = os.path.join(rcynic_root, unauthenticated_subdir)

  base_uri = "rsync://"

  def uri_to_filename(self, uri):
    if uri.startswith(self.base_uri):
      return uri[len(self.base_uri):]
    else:
      raise NotRsyncURI, "Not an rsync URI %r" % uri

  def __iter__(self):
    for validation_status in ElementTree(file=self.xml_file).getroot().getiterator("validation_status"):
      timestamp = validation_status.get("timestamp")
      status = validation_status.get("status")
      uri = validation_status.text.strip()
      generation = validation_status.get("generation")

      # determine the path to this object
      if status == 'object_accepted':
        d = self.authenticated_subdir
      elif generation == 'backup':
        d = self.authenticated_old_subdir
      else:
        d = self.unauthenticated_subdir

      filename = os.path.join(d, self.uri_to_filename(uri))

      ext = os.path.splitext(filename)[1]
      if ext in file_name_classes:
        yield validation_status_element(timestamp = timestamp, generation = generation,
                                        uri=uri, status = status, filename = filename,
                                        file_class = file_name_classes[ext])

def label_iterator(xml_file):
  """
  Returns an iterator which contains all defined labels from an rcynic XML
  output file.  Each item is a tuple of the form
  (label, kind, description).
  """

  for label in ElementTree(file=xml_file).find("labels"):
    yield label.tag, label.get("kind"), label.text.strip()