"""
ldif - generate and parse LDIF data (see RFC 2849)

See http://www.python-ldap.org/ for details.

$Id: ldif.py,v 1.82 2015/06/21 11:38:32 stroeder Exp $

Python compability note:
Tested with Python 2.0+, but should work with Python 1.5.2+.
"""

__version__ = '2.4.20'

__all__ = [
  # constants
  'ldif_pattern',
  # functions
  'CreateLDIF','ParseLDIF',
  # classes
  'LDIFWriter',
  'LDIFParser',
  'LDIFRecordList',
  'LDIFCopy',
]

import urlparse,urllib,base64,re,types

try:
  from cStringIO import StringIO
except ImportError:
  from StringIO import StringIO

attrtype_pattern = r'[\w;.-]+(;[\w_-]+)*'
attrvalue_pattern = r'(([^,]|\\,)+|".*?")'
attrtypeandvalue_pattern = attrtype_pattern + r'[ ]*=[ ]*' + attrvalue_pattern
rdn_pattern   = attrtypeandvalue_pattern + r'([ ]*\+[ ]*' + attrtypeandvalue_pattern + r')*[ ]*'
dn_pattern   = rdn_pattern + r'([ ]*,[ ]*' + rdn_pattern + r')*[ ]*'
dn_regex   = re.compile('^%s$' % dn_pattern)

ldif_pattern = '^((dn(:|::) %(dn_pattern)s)|(%(attrtype_pattern)s(:|::) .*)$)+' % vars()

MOD_OP_INTEGER = {
  'add'    :0, # ldap.MOD_REPLACE
  'delete' :1, # ldap.MOD_DELETE
  'replace':2, # ldap.MOD_REPLACE
}

MOD_OP_STR = {
  0:'add',1:'delete',2:'replace'
}

CHANGE_TYPES = ['add','delete','modify','modrdn']
valid_changetype_dict = {}
for c in CHANGE_TYPES:
  valid_changetype_dict[c]=None


def is_dn(s):
  """
  returns 1 if s is a LDAP DN
  """
  if s=='':
    return 1
  rm = dn_regex.match(s)
  return rm!=None and rm.group(0)==s


SAFE_STRING_PATTERN = '(^(\000|\n|\r| |:|<)|[\000\n\r\200-\377]+|[ ]+$)'
safe_string_re = re.compile(SAFE_STRING_PATTERN)

def list_dict(l):
  """
  return a dictionary with all items of l being the keys of the dictionary
  """
  return dict([(i,None) for i in l])


class LDIFWriter:
  """
  Write LDIF entry or change records to file object
  Copy LDIF input to a file output object containing all data retrieved
  via URLs
  """

  def __init__(self,output_file,base64_attrs=None,cols=76,line_sep='\n'):
    """
    output_file
        file object for output
    base64_attrs
        list of attribute types to be base64-encoded in any case
    cols
        Specifies how many columns a line may have before it's
        folded into many lines.
    line_sep
        String used as line separator
    """
    self._output_file = output_file
    self._base64_attrs = list_dict([a.lower() for a in (base64_attrs or [])])
    self._cols = cols
    self._line_sep = line_sep
    self.records_written = 0

  def _unfold_lines(self,line):
    """
    Write string line as one or more folded lines
    """
    # Check maximum line length
    line_len = len(line)
    if line_len<=self._cols:
      self._output_file.write(line)
      self._output_file.write(self._line_sep)
    else:
      # Fold line
      pos = self._cols
      self._output_file.write(line[0:min(line_len,self._cols)])
      self._output_file.write(self._line_sep)
      while pos<line_len:
        self._output_file.write(' ')
        self._output_file.write(line[pos:min(line_len,pos+self._cols-1)])
        self._output_file.write(self._line_sep)
        pos = pos+self._cols-1
    return # _unfold_lines()

  def _needs_base64_encoding(self,attr_type,attr_value):
    """
    returns 1 if attr_value has to be base-64 encoded because
    of special chars or because attr_type is in self._base64_attrs
    """
    return self._base64_attrs.has_key(attr_type.lower()) or \
           not safe_string_re.search(attr_value) is None

  def _unparseAttrTypeandValue(self,attr_type,attr_value):
    """
    Write a single attribute type/value pair

    attr_type
          attribute type
    attr_value
          attribute value
    """
    if self._needs_base64_encoding(attr_type,attr_value):
      # Encode with base64
      self._unfold_lines(':: '.join([attr_type,base64.encodestring(attr_value).replace('\n','')]))
    else:
      self._unfold_lines(': '.join([attr_type,attr_value]))
    return # _unparseAttrTypeandValue()

  def _unparseEntryRecord(self,entry):
    """
    entry
        dictionary holding an entry
    """
    attr_types = entry.keys()[:]
    attr_types.sort()
    for attr_type in attr_types:
      for attr_value in entry[attr_type]:
        self._unparseAttrTypeandValue(attr_type,attr_value)

  def _unparseChangeRecord(self,modlist):
    """
    modlist
        list of additions (2-tuple) or modifications (3-tuple)
    """
    mod_len = len(modlist[0])
    if mod_len==2:
      changetype = 'add'
    elif mod_len==3:
      changetype = 'modify'
    else:
      raise ValueError("modlist item of wrong length: %d" % (mod_len))
    self._unparseAttrTypeandValue('changetype',changetype)
    for mod in modlist:
      if mod_len==2:
        mod_type,mod_vals = mod
      elif mod_len==3:
        mod_op,mod_type,mod_vals = mod
        self._unparseAttrTypeandValue(MOD_OP_STR[mod_op],mod_type)
      else:
        raise ValueError("Subsequent modlist item of wrong length")
      if mod_vals:
        for mod_val in mod_vals:
          self._unparseAttrTypeandValue(mod_type,mod_val)
      if mod_len==3:
        self._output_file.write('-'+self._line_sep)

  def unparse(self,dn,record):
    """
    dn
          string-representation of distinguished name
    record
          Either a dictionary holding the LDAP entry {attrtype:record}
          or a list with a modify list like for LDAPObject.modify().
    """
    # Start with line containing the distinguished name
    self._unparseAttrTypeandValue('dn',dn)
    # Dispatch to record type specific writers
    if isinstance(record,types.DictType):
      self._unparseEntryRecord(record)
    elif isinstance(record,types.ListType):
      self._unparseChangeRecord(record)
    else:
      raise ValueError('Argument record must be dictionary or list instead of %s' % (repr(record)))
    # Write empty line separating the records
    self._output_file.write(self._line_sep)
    # Count records written
    self.records_written = self.records_written+1
    return # unparse()


def CreateLDIF(dn,record,base64_attrs=None,cols=76):
  """
  Create LDIF single formatted record including trailing empty line.
  This is a compability function. Use is deprecated!

  dn
        string-representation of distinguished name
  record
        Either a dictionary holding the LDAP entry {attrtype:record}
        or a list with a modify list like for LDAPObject.modify().
  base64_attrs
        list of attribute types to be base64-encoded in any case
  cols
        Specifies how many columns a line may have before it's
        folded into many lines.
  """
  f = StringIO()
  ldif_writer = LDIFWriter(f,base64_attrs,cols,'\n')
  ldif_writer.unparse(dn,record)
  s = f.getvalue()
  f.close()
  return s


class LDIFParser:
  """
  Base class for a LDIF parser. Applications should sub-class this
  class and override method handle() to implement something meaningful.

  Public class attributes:

  records_read
        Counter for records processed so far
  """

  def __init__(
    self,
    input_file,
    ignored_attr_types=None,
    max_entries=0,
    process_url_schemes=None,
    line_sep='\n'
  ):
    """
    Parameters:
    input_file
        File-object to read the LDIF input from
    ignored_attr_types
        Attributes with these attribute type names will be ignored.
    max_entries
        If non-zero specifies the maximum number of entries to be
        read from f.
    process_url_schemes
        List containing strings with URLs schemes to process with urllib.
        An empty list turns off all URL processing and the attribute
        is ignored completely.
    line_sep
        String used as line separator
    """
    self._input_file = input_file
    self._max_entries = max_entries
    self._process_url_schemes = list_dict([s.lower() for s in (process_url_schemes or [])])
    self._ignored_attr_types = list_dict([a.lower() for a in (ignored_attr_types or [])])
    self._line_sep = line_sep
    self.line_counter = 0
    self.byte_counter = 0
    self.records_read = 0
    self._line = self._readline()

  def handle(self,dn,entry):
    """
    Process a single content LDIF record. This method should be
    implemented by applications using LDIFParser.
    """
    pass

  def _readline(self):
    s = self._input_file.readline()
    self.line_counter = self.line_counter + 1
    self.byte_counter = self.byte_counter + len(s)
    if s[-2:]=='\r\n':
      return s[:-2]
    elif s[-1:]=='\n':
      return s[:-1]
    else:
      return s

  def _unfold_lines(self):
    """
    Unfold several folded lines with trailing space into one line
    """
    unfolded_lines = [ self._line ]
    self._line = self._readline()
    while self._line and self._line[0]==' ':
      unfolded_lines.append(self._line[1:])
      self._line = self._readline()
    return ''.join(unfolded_lines)

  def _next_key_and_value(self):
    """
    Parse a single attribute type and value pair from one or
    more lines of LDIF data
    """
    # Reading new attribute line
    unfolded_line = self._unfold_lines()
    # Ignore comments which can also be folded
    while unfolded_line and unfolded_line[0]=='#':
      unfolded_line = self._unfold_lines()
    if not unfolded_line:
      return None,None
    if unfolded_line=='-':
      return '-',None
    colon_pos = unfolded_line.index(':')
    attr_type = unfolded_line[0:colon_pos]
    # if needed attribute value is BASE64 decoded
    value_spec = unfolded_line[colon_pos:colon_pos+2]
    if value_spec==': ':
      attr_value = unfolded_line[colon_pos+2:]
    elif value_spec=='::':
      # attribute value needs base64-decoding
      attr_value = base64.decodestring(unfolded_line[colon_pos+2:])
    elif value_spec==':<':
      # fetch attribute value from URL
      url = unfolded_line[colon_pos+2:].strip()
      attr_value = None
      if self._process_url_schemes:
        u = urlparse.urlparse(url)
        if self._process_url_schemes.has_key(u[0]):
          attr_value = urllib.urlopen(url).read()
    elif value_spec==':\r\n' or value_spec=='\n':
      attr_value = ''
    return attr_type,attr_value

  def parse_entry_records(self):
    """
    Continously read and parse LDIF entry records
    """
    k,v = self._next_key_and_value()
    if k=='version':
      self.version = v
      k,v = self._next_key_and_value()
      if k==v==None:
        k,v = self._next_key_and_value()
    else:
      self.version = None

    # Loop for processing whole records
    while k!=None and \
          (not self._max_entries or self.records_read<self._max_entries):
      # Consume first line which must start with "dn: "
      if k!='dn':
        raise ValueError('Line %d: First line of record does not start with "dn:": %s' % (self.line_counter,repr(k)))
      if not is_dn(v):
        raise ValueError('Line %d: Not a valid string-representation for dn: %s.' % (self.line_counter,repr(v)))
      dn = v
      entry = {}
      # Consume second line of record
      k,v = self._next_key_and_value()

      # Loop for reading the attributes
      while k!=None and \
         not k.lower() in self._ignored_attr_types:
        # Add the attribute to the entry if not ignored attribute
        try:
          entry[k].append(v)
        except KeyError:
          entry[k]=[v]
        # Read the next line within the record
        k,v = self._next_key_and_value()
      # Consume empty separator line
      k,v = self._next_key_and_value()
      if entry:
        # append entry to result list
        self.handle(dn,entry)
      self.records_read = self.records_read + 1

    return # parse_entry_records()

  def parse(self):
    """
    Invokes LDIFParser.parse_entry_records() for backward compability
    """
    return self.parse_entry_records() # parse()

  def handle_change_modify(self,dn,modops,controls=None):
    """
    Process a single LDIF record representing a single modify operation.
    This method should be implemented by applications using LDIFParser.
    """
    controls = [] or None
    pass

  def parse_change_records(self):
    self.changetype_counter = {}
    k,v = self._next_key_and_value()
    if k=='version':
      self.version = v
      k,v = self._next_key_and_value()
      if k==v==None:
        k,v = self._next_key_and_value()
    else:
      self.version = None

    # Loop for processing whole records
    while k!=None and \
          (not self._max_entries or self.records_read<self._max_entries):

      # Consume first line which must start with "dn: "
      if k!='dn':
        raise ValueError('Line %d: First line of record does not start with "dn:": %s' % (self.line_counter,repr(k)))
      if not is_dn(v):
        raise ValueError('Line %d: Not a valid string-representation for dn: %s' % (self.line_counter,repr(v)))
      dn = v
      # Read "control:" lines
      controls = []
      k,v = self._next_key_and_value()
      while k=='control':
        try:
          control_type,criticality,control_value = v.split(' ',2)
        except ValueError:
          control_value = None
          control_type,criticality = v.split(' ',1)
        controls.append((control_type,criticality,control_value))
        k,v = self._next_key_and_value()
      # Determine changetype first, assuming changetype: as default
      changetype = 'modify'
      # Consume second line of record
      if k=='changetype':
        if not v in valid_changetype_dict:
          raise ValueError('Invalid changetype: %s' % repr(v))
        changetype = v
        k,v = self._next_key_and_value()

      if changetype=='modify':

        # From here we assume a change record is read with changetype: modify
        modops = []

        # Loop for reading the list of modifications
        while k!=None:
          # Extract attribute mod-operation (add, delete, replace)
          try:
            modop = MOD_OP_INTEGER[k]
          except KeyError:
            raise ValueError('Line %d: Invalid mod-op string: %s' % (self.line_counter,repr(k)))
          # we now have the attribute name to be modified
          modattr = v
          modvalues = []
          k,v = self._next_key_and_value()
          while k==modattr:
            modvalues.append(v)
            k,v = self._next_key_and_value()
          modops.append((modop,modattr,modvalues or None))
          k,v = self._next_key_and_value()
          if k=='-':
            # Consume next line
            k,v = self._next_key_and_value()

        if modops:
          # append entry to result list
          self.handle_modify(dn,modops,controls)

      else:

        # Consume the unhandled change record
        while k!=None:
          k,v = self._next_key_and_value()

      # Consume empty separation line
      k,v = self._next_key_and_value()

      # Increment record counters
      try:
        self.changetype_counter[changetype] = self.changetype_counter[changetype] + 1
      except KeyError:
        self.changetype_counter[changetype] = 1
      self.records_read = self.records_read + 1

    return # parse_change_records()


class LDIFRecordList(LDIFParser):
  """
  Collect all records of LDIF input into a single list.
  of 2-tuples (dn,entry). It can be a memory hog!
  """

  def __init__(
    self,
    input_file,
    ignored_attr_types=None,max_entries=0,process_url_schemes=None
  ):
    """
    See LDIFParser.__init__()

    Additional Parameters:
    all_records
        List instance for storing parsed records
    """
    LDIFParser.__init__(self,input_file,ignored_attr_types,max_entries,process_url_schemes)
    self.all_records = []
    self.all_modify_changes = []

  def handle(self,dn,entry):
    """
    Append single record to dictionary of all records.
    """
    self.all_records.append((dn,entry))

  def handle_modify(self,dn,modops,controls=None):
    """
    Process a single LDIF record representing a single modify operation.
    This method should be implemented by applications using LDIFParser.
    """
    controls = [] or None
    self.all_modify_changes.append((dn,modops,controls))


class LDIFCopy(LDIFParser):
  """
  Copy LDIF input to LDIF output containing all data retrieved
  via URLs
  """

  def __init__(
    self,
    input_file,output_file,
    ignored_attr_types=None,max_entries=0,process_url_schemes=None,
    base64_attrs=None,cols=76,line_sep='\n'
  ):
    """
    See LDIFParser.__init__() and LDIFWriter.__init__()
    """
    LDIFParser.__init__(self,input_file,ignored_attr_types,max_entries,process_url_schemes)
    self._output_ldif = LDIFWriter(output_file,base64_attrs,cols,line_sep)

  def handle(self,dn,entry):
    """
    Write single LDIF record to output file.
    """
    self._output_ldif.unparse(dn,entry)


def ParseLDIF(f,ignore_attrs=None,maxentries=0):
  """
  Parse LDIF records read from file.
  This is a compability function. Use is deprecated!
  """
  ldif_parser = LDIFRecordList(
    f,ignored_attr_types=ignore_attrs,max_entries=maxentries,process_url_schemes=0
  )
  ldif_parser.parse()
  return ldif_parser.all_records


if __name__ == '__main__':
  import sys,os,time,pprint
  parser_class_name = sys.argv[1]
  parser_class = vars()[parser_class_name]
  parser_method_name = sys.argv[2]
  for input_file_name in sys.argv[3:]:
    input_file_size = os.stat(input_file_name).st_size
    input_file = open(input_file_name,'rb')
    ldif_parser = parser_class(input_file)
    parser_method = getattr(ldif_parser,parser_method_name)
    start_time = time.time()
    parser_method()
    end_time = time.time()
    input_file.close()
    print '***Time needed:',end_time-start_time,'seconds'
    print '***Records read:',ldif_parser.records_read
    print '***Lines read:',ldif_parser.line_counter
    print '***Bytes read:',ldif_parser.byte_counter,'of',input_file_size
