## @file csfile.py
# @brief  Provide a module to read, write and treat with a csback chechsumfile.
# 
# -----------------------------------------------------------------------------
# 
# $Id$
# @author Daniel Armbruster
# \date 15/09/2011
# 
# Purpose: Provide a module to read, write and treat with a csback checksumfile.
# file.
#
# ----
# This file is part of csback.
#
# csback 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 3 of the License, or
# (at your option) any later version.
# 
# csback 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 csback.  If not, see <http://www.gnu.org/licenses/>.
# ----
# 
# Copyright (c) 2011 by Daniel Armbruster
# 
# REVISIONS and CHANGES 
# 15/09/2011  V0.1    Daniel Armbruster
# 
# =============================================================================

import os
import re
import sys
import hashlib

__version__ = "V0.1"
__subversion__ = "Id: "
__license__ = "GPLv2"
__author__ = "Daniel Armbruster"
__copyright__ = "Copyright (c) 2011 by Daniel Armbruster"

# -----------------------------------------------------------------------------
class CsFileError(Exception):

  def __init__(self, msg):
    self.msg = msg

  def display(self):
    sys.stderr.write("csFile (ERROR): " + self.msg + "\n")

# -----------------------------------------------------------------------------
class CsFile:

  def __init__(self, filename, hashfunc=hashlib.sha256):
    self.__filename = filename
    self.__cslines = []
    self.__hashfunc = hashfunc

  def read(self):
    if not os.path.isfile(self.__filename):
      raise CsFileError("CSFILE is not a regular file.")
    if 0 == os.stat(self.__filename).st_size:
      raise CsFileError("CSFILE is an empty file.")
    csfile = open(self.__filename)
    try:
      self.__cslines = [CsLine(line.split()) for line in csfile \
      if len(line.rstrip()) and line[0] != '#'] 
    finally:
      csfile.close()

  def write(self):
    if 0 == len(self.__cslines):
      raise CsFileError("CSFILE does not contain any lines.")
    file = open(self.__filename, 'w')
    for csline in self.__cslines:
      file.write(str(csline) + '\n')
    file.close()

  def update(self, regex):
    pass

  def checkLines(self):
    if 0 == len(self.__cslines):
      raise CsFileError("CSFILE does not contain any lines.")
    for line in self.__cslines:
      line.check()

  def displayLines(self):
    if 0 == len(self.__cslines):
      raise CsFileError("CSFILE does not contain any lines.")
    for line in self.__cslines:
      sys.stdout.write(line)

  def addLine(self, csline):
    if isinstance(csline, CsLine):
      self.__cslines.append(csline)
    else:
      raise CsFileError("Argument must be of type CsLine.")
    
  def removeLine(self, index):
    if 0 <= index and len(self.__cslines) >= index:
      del self.__cslines[index]
    else:
      raise CsFileError("Index out of range.")

# -----------------------------------------------------------------------------
class CsLine:
  def __init__(self, file, hashfunc = hashlib.sha256):
    pass

# -----------------------------------------------------------------------------
if __name__ == '__main__':
  pass
  
  
# ----- END OF csfile.py -----