
# 
#   Copyright 2016 RIFT.IO Inc
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#

'''
Exceptions for the YANG Translator package.
'''

import logging
import sys
import traceback

from rift.mano.yang_translator.common.utils import _

log = logging.getLogger(__name__)


class YANGException(Exception):
    '''Base exception class for YANG

    To correctly use this class, inherit from it and define
    a 'msg_fmt' property.

    '''

    _FATAL_EXCEPTION_FORMAT_ERRORS = False

    message = _('An unknown exception occurred.')

    def __init__(self, **kwargs):
        try:
            self.message = self.msg_fmt % kwargs
        except KeyError:
            exc_info = sys.exc_info()
            log.exception(_('Exception in string format operation: %s')
                          % exc_info[1])

            if YANGException._FATAL_EXCEPTION_FORMAT_ERRORS:
                raise exc_info[0]

    def __str__(self):
        return self.message

    @staticmethod
    def generate_inv_schema_property_error(self, attr, value, valid_values):
        msg = (_('Schema definition of "%(propname)s" has '
                 '"%(attr)s" attribute with invalid value '
                 '"%(value1)s". The value must be one of '
                 '"%(value2)s".') % {"propname": self.name,
                                     "attr": attr,
                                     "value1": value,
                                     "value2": valid_values})
        ExceptionCollector.appendException(
            InvalidSchemaError(message=msg))

    @staticmethod
    def set_fatal_format_exception(flag):
        if isinstance(flag, bool):
            YANGException._FATAL_EXCEPTION_FORMAT_ERRORS = flag


class MissingRequiredFieldError(YANGException):
    msg_fmt = _('%(what)s is missing required field "%(required)s".')


class UnknownFieldError(YANGException):
    msg_fmt = _('%(what)s contains unknown field "%(field)s". Refer to the '
                'definition to verify valid values.')


class TypeMismatchError(YANGException):
    msg_fmt = _('%(what)s must be of type "%(type)s".')


class InvalidNodeTypeError(YANGException):
    msg_fmt = _('Node type "%(what)s" is not a valid type.')


class InvalidTypeError(YANGException):
    msg_fmt = _('Type "%(what)s" is not a valid type.')


class InvalidSchemaError(YANGException):
    msg_fmt = _('%(message)s')


class ValidationError(YANGException):
    msg_fmt = _('%(message)s')


class UnknownInputError(YANGException):
    msg_fmt = _('Unknown input "%(input_name)s".')


class InvalidPropertyValueError(YANGException):
    msg_fmt = _('Value of property "%(what)s" is invalid.')


class InvalidTemplateVersion(YANGException):
    msg_fmt = _('The template version "%(what)s" is invalid. '
                'Valid versions are "%(valid_versions)s".')


class InvalidYANGVersionPropertyException(YANGException):
    msg_fmt = _('Value of YANG version property "%(what)s" is invalid.')


class URLException(YANGException):
    msg_fmt = _('%(what)s')


class YangExtImportError(YANGException):
    msg_fmt = _('Unable to import extension "%(ext_name)s". '
                'Check to see that it exists and has no '
                'language definition errors.')


class YangExtAttributeError(YANGException):
    msg_fmt = _('Missing attribute in extension "%(ext_name)s". '
                'Check to see that it has required attributes '
                '"%(attrs)s" defined.')


class InvalidGroupTargetException(YANGException):
    msg_fmt = _('"%(message)s"')


class ConfFileParseError(YANGException):
    msg_fmt = _('%(message)s')


class ConfOptionNotDefined(YANGException):
    msg_fmt = _('Option %(key)s in section %(section)s '
                'is not defined in conf file')


class ConfSectionNotDefined(YANGException):
    msg_fmt = _('Section %(section)s is not defined in conf file')


class YangModImportError(YANGException):
    msg_fmt = _('Unable to import module %(mod_name)s. '
                'Check to see that it exists and has no '
                'language definition errors.')


class YangClassImportError(YANGException):
    msg_fmt = _('Unable to import class %(name)s in '
                'module %(mod_name)s. Check to see that it '
                'exists and has no language definition errors.')


class YangClassAttributeError(YANGException):
    msg_fmt = _('Class attribute referenced not found. '
                '%(message)s. Check to see that it is defined.')


class ExceptionCollector(object):

    exceptions = []
    collecting = False

    @staticmethod
    def clear():
        del ExceptionCollector.exceptions[:]

    @staticmethod
    def start():
        ExceptionCollector.clear()
        ExceptionCollector.collecting = True

    @staticmethod
    def stop():
        ExceptionCollector.collecting = False

    @staticmethod
    def contains(exception):
        for ex in ExceptionCollector.exceptions:
            if str(ex) == str(exception):
                return True
        return False

    @staticmethod
    def appendException(exception):
        if ExceptionCollector.collecting:
            if not ExceptionCollector.contains(exception):
                exception.trace = traceback.extract_stack()[:-1]
                ExceptionCollector.exceptions.append(exception)
        else:
            raise exception

    @staticmethod
    def exceptionsCaught():
        return len(ExceptionCollector.exceptions) > 0

    @staticmethod
    def getTraceString(traceList):
        traceString = ''
        for entry in traceList:
            f, l, m, c = entry[0], entry[1], entry[2], entry[3]
            traceString += (_('\t\tFile %(file)s, line %(line)s, in '
                              '%(method)s\n\t\t\t%(call)s\n')
                            % {'file': f, 'line': l, 'method': m, 'call': c})
        return traceString

    @staticmethod
    def getExceptionReportEntry(exception, full=True):
        entry = exception.__class__.__name__ + ': ' + str(exception)
        if full:
            entry += '\n' + ExceptionCollector.getTraceString(exception.trace)
        return entry

    @staticmethod
    def getExceptions():
        return ExceptionCollector.exceptions

    @staticmethod
    def getExceptionsReport(full=True):
        report = []
        for exception in ExceptionCollector.exceptions:
            report.append(
                ExceptionCollector.getExceptionReportEntry(exception, full))
        return report

    @staticmethod
    def assertExceptionMessage(exception, message):
        err_msg = exception.__name__ + ': ' + message
        report = ExceptionCollector.getExceptionsReport(False)
        assert err_msg in report, (_('Could not find "%(msg)s" in "%(rep)s".')
                                   % {'rep': report.__str__(), 'msg': err_msg})
