# Copyright (C) 2011, 2012 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.logging
import PISM.vec

def pauseListener(*args):
  """Listener that temporarily halts operation at each iteration waiting for a key press."""
  PISM.logging.pause()


class PlotListener:
  """Base class for listeners that create plots of vectors at each iteration. 
Provides objects for converting :cpp:class:`IceModelVec`\'s to ``numpy`` vectors
on processor zero, as well as basic ``matplotlib`` figure management."""
  def __init__(self,grid):
    self.grid = grid
    self.tz_scalar = PISM.vec.ToProcZero(grid,dof=1)
    self.tz_vector = PISM.vec.ToProcZero(grid,dof=2)
    self.figs = {}

  def toproczero(self,*args):
    """Returns a ``numpy`` vector on processor zero corresponding to an :cpp:class:`IceModelVec`.
    Takes as input either a single :cpp:class:`IceModelVec` or dictionary of such
    vectors and the name of an entry. Returns ``None`` on other processors."""
    if len(args) == 2:
      data = args[0]
      name = args[1]
      v = data[name]
    else:
      v = args[0]
    if v is None:
      return None
    if v.get_dof()==1:
      return self.tz_scalar.communicate(v)
    return self.tz_vector.communicate(v)

  def figure(self,name='default'):
    """Returns a ``matplotlib`` figure based on a string name.  If the instance has not yet
    created a figure with the given name, a new figure is created and associated with the given name."""
    fig = self.figs.get(name)
    if fig is None:
      import matplotlib.pyplot as pp
      fig = pp.figure()
      self.figs[name]=fig
    return fig.number

  def __call__(self,solver,itr,data):
    raise NotImplementedError()