# Source code for qcdb.pdict

    #
    #@BEGIN LICENSE
    #
    # PSI4: an ab initio quantum chemistry software package
    #
    # This program 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 2 of the License, or
    # (at your option) any later version.
    #
    # This program 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 this program; if not, write to the Free Software Foundation, Inc.,
    # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
    #
    #@END LICENSE
    #

    from decimal import Decimal, ROUND_FLOOR, ROUND_CEILING
    import qcdb.exceptions

    class PreservingDict(dict):
        """Class to store quantum chemical quantities extracted from output
        files. Extends the dictionary object to (1) store key as all-caps
        version of itself and (2) validate value for duplicate values for the
        same key by testing which has more decimal places and whether value
        the same within a plausing rounding error. Allows consistency checks
        when parsing output files without loss of precision.

        """

        def __init__(self, *args, **kwargs):
            self.update(*args, **kwargs)

        def __setitem__(self, key, value):
            try:
                key = key.upper()
            except AttributeError:
                raise AttributeError('Keys stored as upper-case strings: %s unsuitable' % (key))
            value = Decimal(value)
            if key in self.keys() and not 'CURRENT' in key:
                # Validate choosing more detailed value for variable
                existing_exp = self[key].as_tuple().exponent  # 0.1111 --> -4
                candidate_exp = value.as_tuple().exponent
                if existing_exp > candidate_exp:  # candidate has more digits
                    places = Decimal(10) ** (existing_exp + 1)  # exp+1 permits slack in rounding
                    best_value = value
                else:                             # existing has more digits
                    places = Decimal(10) ** (candidate_exp + 1)
                    best_value = self[key]
                # Validate values are the same
                #print('FLOOR: ', self[key].quantize(places, rounding=ROUND_FLOOR) - value.quantize(places, rounding=ROUND_FLOOR))
                #print('CEIL:  ', self[key].quantize(places, rounding=ROUND_CEILING) - value.quantize(places, rounding=ROUND_CEILING))
                if (self[key].quantize(places, rounding=ROUND_CEILING).compare(value.quantize(places, rounding=ROUND_CEILING)) != 0) and \
                   (self[key].quantize(places, rounding=ROUND_FLOOR).compare(value.quantize(places, rounding=ROUND_FLOOR)) != 0):
                    raise qcdb.exceptions.ParsingValidationError(
                        """Output file yielded both %s and %s as values for quantity %s.""" %
                        (self[key].to_eng_string(), value.to_eng_string(), key))
                #print 'Resetting variable %s to %s' % (key, best_value.to_eng_string())
            else:
                best_value = value
                #print 'Setting   variable %s to %s' % (key, best_value.to_eng_string())
            super(PreservingDict, self).__setitem__(key, best_value)

        def update(self, *args, **kwargs):
            if args:
                if len(args) > 1:
                    raise TypeError("update expected at most 1 arguments, "
                                    "got %d" % len(args))
                other = dict(args[0])
                for key in other:
                    self[key] = other[key]
            for key in kwargs:
                self[key] = kwargs[key]

        def setdefault(self, key, value=None):
            if key not in self:
                self[key] = value
            return self[key]

    if __name__ == '__main__':
        c4info = PreservingDict()
        c4info['scf 4.5e0 total energy'] = '-1.e-4'
        c4info['1.3'] = '.4'
        c4info['curl'] = '-437.12345678'
        c4info['curl'] = '-437.12345677'
        c4info['curl'] = '-437.123456'
        c4info['curl'] = '-437.123457'
        c4info['curl'] = '-437.1234444'  # fails
        c4info['curl'] = '-437.123456789'
        #c4info['curl'] = '-437.1234567779'  # fails
        print c4info