# Copyright (C) 2011, 2012, 2013 David Maxwell
# 
# This file is part of PISM.
# 
# PISM 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.
# 
# PISM 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 PISM; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA


import PISM, time, sys

"""Utility functions/objects that don't have a good home elsewhere."""

def writeProvenance(outfile,message=None):
  """Saves the time and command line arguments (or the provided `message`) to 
  the ``history`` attribute of the :file:`.nc` file `outfile`"""
  rank = PISM.Context().rank
  if rank == 0:
    nc = PISM.netCDF.Dataset(outfile, 'a')  # append
    if message is None:
      message = time.asctime() + ': ' + ' '.join(sys.argv)
    if 'history' in nc.ncattrs():
      nc.history = message + '\n' + nc.history
    else:
      nc.history = message
    nc.source = "PISM " + PISM.PISM_Revision
    nc.close()
  PISM.Context().com.barrier()


def fileHasVariable(filename,varname):
  """Returns ``True`` if the :file:`.nc` file `filename` contains an attribute named `varname`."""
  ds = PISM.netCDF.Dataset(filename)
  has_var = ds.variables.has_key(varname)
  ds.close()
  return has_var

# The following was copied from matplotlib, which copied a python recipe.
class Bunch:
  """
  Often we want to just collect a bunch of stuff together, naming each
  item of the bunch; a dictionary's OK for that, but a small do- nothing
  class is even handier, and prettier to use.  Whenever you want to
  group a few variables:

    >>> point = Bunch(datum=2, squared=4, coord=12)
    >>> point.datum
    By: Alex Martelli
    From: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52308"""

  def __init__(self, **kwds):
      self.__dict__.update(kwds)

  def has_key(self,k):
    return self.__dict__.has_key(k)

  def __getitem__(self,k):
    return self.__dict__.get(k)

  def update(self,**kwds):
    self.__dict__.update(**kwds)

  def __repr__(self):
      keys = self.__dict__.keys()
      return 'Bunch(%s)'%', '.join(['%s=%s'%(k,self.__dict__[k]) for k in keys])