# Source code for taurus.core.epics.epicsvalidator

    #!/usr/bin/env python
    # ###########################################################################
    #
    # This file is part of Taurus
    #
    # http://taurus-scada.org
    #
    # Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
    #
    # Taurus 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 3 of the License, or
    # (at your option) any later version.
    #
    # Taurus 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 Taurus.  If not, see <http://www.gnu.org/licenses/>.
    #
    # ###########################################################################

    """
    Epics module. See __init__.py for more detailed documentation
    """
    __all__ = [
        "EpicsAuthorityNameValidator",
        "EpicsDeviceNameValidator",
        "EpicsAttributeNameValidator",
    ]

    from taurus.core.taurusvalidator import (
        TaurusAttributeNameValidator,
        TaurusDeviceNameValidator,
        TaurusAuthorityNameValidator,
    )

    # legal chars on PV names: a-z A-Z 0-9 _ - : . [ ] < > ;
    # ... but "[" "]" and "." are discouraged:
    # http://www.aps.anl.gov/epics/tech-talk/2006/msg00431.php
    PV_CHARS = r"[a-zA-Z0-9_\-:;\<\>" + r"[\.\[\]]"

    class EpicsAuthorityNameValidator(TaurusAuthorityNameValidator):
        """Validator for Epics authority names. For now, the only supported
        authority is "//":
        """

        scheme = "(ca|epics)"
        authority = "//"
        path = "(?!)"
        query = "(?!)"
        fragment = "(?!)"

        def getNames(self, fullname, factory=None):
            if self.isValid(fullname):
                return "ca://", "//", ""
            return None

    class EpicsDeviceNameValidator(TaurusDeviceNameValidator):
        """Validator for Epics device names. Apart from the standard named
        groups (scheme, authority, path, query and fragment), the following named
        groups are created:

         - devname: device name (only empty string allowed for now)

        Note: brackets on the group name indicate that this group will only contain
        a string if the URI contains it.
        """

        scheme = "(ca|epics)"
        authority = EpicsAuthorityNameValidator.authority
        path = r"/(?P<devname>)"  # (only empty string allowed for now)
        query = "(?!)"
        fragment = "(?!)"

        def getNames(self, fullname, factory=None):
            if self.isValid(fullname):
                return "ca:", "", ""
            return None

    class EpicsAttributeNameValidator(TaurusAttributeNameValidator):
        """Validator for Epics attribute names. Apart from the standard named
        groups (scheme, authority, path, query and fragment), the following named
        groups are created:

         - attrname: attribute name (an epics PV name).

        Note: brackets on the group name indicate that this group will only contain
        a value if the URI contains it.
        """

        scheme = "(ca|epics)"
        authority = EpicsAuthorityNameValidator.authority
        path = r"(?P<attrname>%s+?(\.(?P<_field>[A-Z]+))?)" % PV_CHARS
        query = "(?!)"
        fragment = "[^# ]*"

        def getNames(self, fullname, factory=None, fragment=False):
            """reimplemented from :class:`TaurusDeviceNameValidator`"""

            groups = self.getUriGroups(fullname)
            if groups is None:
                return None

            complete = "ca:%s" % groups["attrname"]
            normal = groups["attrname"]
            short = normal

            # return fragment if requested
            if fragment:
                key = groups.get("fragment", None)
                return complete, normal, short, key
            return complete, normal, short