#MDANSE : Molecular Dynamics Analysis for Neutron Scattering Experiments
#------------------------------------------------------------------------------------------
#Copyright (C)
#2015- Eric C. Pellegrini Institut Laue-Langevin
#BP 156
#6, rue Jules Horowitz
#38042 Grenoble Cedex 9
#France
#pellegrini[at]ill.fr
#goret[at]ill.fr
#aoun[at]ill.fr
#
#This library is free software; you can redistribute it and/or
#modify it under the terms of the GNU Lesser General Public
#License as published by the Free Software Foundation; either
#version 2.1 of the License, or (at your option) any later version.
#
#This library 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
#Lesser General Public License for more details.
#
#You should have received a copy of the GNU Lesser General Public
#License along with this library; if not, write to the Free Software
#Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

''' 
Created on Mar 27, 2015

:author: Eric C. Pellegrini
'''

import time

from MDANSE import REGISTRY
from MDANSE.Core.Error import Error

class UserDefinitionError(Error):
    pass

class IUserDefinition(dict):
    '''
    Base class for user definable objects. User definable objects are objects used in MDANSE for 
    storing information that can be reused later when setting up jobs (e.g. k-vectors defintion, 
    atom selection ...). A user definable object is a dictionary with a predefined set of keys that 
    depends on the user definable object. Object serialization is the underlying mechanism used to 
    save those objets and is done using cPickle module. 
    '''
    
    # Any user definable object will be registered at MDANSE startup.
    __metaclass__ = REGISTRY

    # The base class has no type (hence it will not be registered)    
    type = "user_definition"
    
    # The base class has no predefined set keywords
    _keywords = []
    
    def __init__(self, target, **kwargs):
        '''
        The constructor
        '''
        
        self._target = target
        
        self._creationTime = time.ctime()
        
        for k in self._keywords:
            try:
                self[k] = kwargs[k]
            except KeyError:
                raise UserDefinitionError("Incomplete user definable object: missing %r key" % k)
                                                                                        
    @property
    def target(self):
        
        return self._target

    @classmethod
    def keywords(self):
        
        return self._keywords

    @property
    def creationTime(self):
        
        return self._creationTime

    def __setitem__(self, item, value):
        
        if item in self._keywords:
            dict.__setitem__(self,item,value)
        
    def __str__(self):
        '''
        Return the informal representation of a user definable object
        '''
        
        info = ["Created on: %s\n" % self.creationTime] + ["%s:\n%s\n" % (k,self[k]) for k in self._keywords] 
        
        return "".join(info)