# This file is part of A Boneless Datastructure Language
# Copyright (C) 2020  Soni L.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

"""ABDL Exceptions.

The exceptions for pattern and validation errors are defined here.
"""

import warnings

class DeprecationError(Exception):
    """Raised for deprecated features, if they are disabled.

    This class controls warning/error behaviour of deprecated features.

    Note: This class is deprecated. Use ``abdl.feature`` instead.
    """
    # enable_key_match_compat = False
    # warn_key_match_compat = False

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        warnings.warn("DeprecationError is deprecated. "
                      "Use ``abdl.feature`` instead.", DeprecationWarning)

    @classmethod
    def warn_all(cls):
        """Enables all deprecation warnings."""
        warnings.warn("DeprecationError is deprecated. "
                      "Use ``abdl.feature`` instead.", DeprecationWarning)

class PatternError(Exception):
    """Raised for invalid input or output expressions."""
    # TODO implement formatting

    def __init__(self, msg, pattern=None, defs=None, pos=None, toks=None):
        super().__init__(msg, pattern, defs, pos, toks)
        self.msg = msg
        self.pattern = pattern
        self.defs = defs
        self.pos = pos
        self._toks = toks # internal use

    def _normalize(self, pattern, defs):
        if pattern is not None:
            if self.pattern is not None:
                raise ValueError("Attempt to normalize normalized pattern")
            self.pattern = pattern
        if defs is not None:
            if self.defs is not None:
                raise ValueError("Attempt to normalize normalized defs")
            self.defs = defs

class ValidationError(Exception):
    """Raised when the object tree doesn't validate against the given pattern."""
    # FIXME TODO?