# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.

import re
from datetime import (datetime, tzinfo, timedelta)
try:
    from functools import total_ordering
except ImportError:
    from total_ordering import total_ordering

from aria.parser import implements_specification
from aria.utils.collections import (StrictDict, OrderedDict)
from aria.utils.formatting import safe_repr

from .modeling.data_types import (coerce_to_data_type_class, report_issue_for_bad_format,
                                  coerce_value)


class Timezone(tzinfo):
    """
    Timezone as fixed offset in hours and minutes east of UTC.
    """

    def __init__(self, hours=0, minutes=0):
        super(Timezone, self).__init__()
        self._offset = timedelta(hours=hours, minutes=minutes)

    def utcoffset(self, dt):                                                                        # pylint: disable=unused-argument
        return self._offset

    def tzname(self, dt):                                                                           # pylint: disable=unused-argument
        return unicode(self._offset)

    def dst(self, dt):                                                                              # pylint: disable=unused-argument
        return Timezone._ZERO

    _ZERO = timedelta(0)


UTC = Timezone()


@total_ordering
@implements_specification('timestamp', 'yaml-1.1')
class Timestamp(object):
    '''
    TOSCA timestamps follow the YAML specification, which in turn is a variant of ISO8601.

    Long forms and short forms (without time of day and assuming UTC timezone) are supported for
    parsing. The canonical form (for rendering) matches the long form at the UTC timezone.

    See the `Timestamp Language-Independent Type for YAML Version 1.1 (Working Draft 2005-01-18)
    <http://yaml.org/type/timestamp.html>`__
    '''

    REGULAR_SHORT = r'^(?P<year>[0-9][0-9][0-9][0-9])-(?P<month>[0-9][0-9])-(?P<day>[0-9][0-9])$'
    REGULAR_LONG = \
        r'^(?P<year>[0-9][0-9][0-9][0-9])-(?P<month>[0-9][0-9]?)-(?P<day>[0-9][0-9]?)' + \
        r'([Tt]|[ \t]+)' \
        r'(?P<hour>[0-9][0-9]?):(?P<minute>[0-9][0-9]):(?P<second>[0-9][0-9])' + \
        r'(?P<fraction>\.[0-9]*)?' + \
        r'(([ \t]*)Z|(?P<tzhour>[-+][0-9][0-9])?(:(?P<tzminute>[0-9][0-9])?)?)?$'
    CANONICAL = '%Y-%m-%dT%H:%M:%S'

    def __init__(self, entry_schema, constraints, value, aspect):                                   # pylint: disable=unused-argument
        value = unicode(value)
        match = re.match(Timestamp.REGULAR_SHORT, value)
        if match is not None:
            # Parse short form
            year = int(match.group('year'))
            month = int(match.group('month'))
            day = int(match.group('day'))
            self.value = datetime(year, month, day, tzinfo=UTC)
        else:
            match = re.match(Timestamp.REGULAR_LONG, value)
            if match is not None:
                # Parse long form
                year = int(match.group('year'))
                month = int(match.group('month'))
                day = int(match.group('day'))
                hour = match.group('hour')
                if hour is not None:
                    hour = int(hour)
                minute = match.group('minute')
                if minute is not None:
                    minute = int(minute)
                second = match.group('second')
                if second is not None:
                    second = int(second)
                fraction = match.group('fraction')
                if fraction is not None:
                    fraction = int(float(fraction) * 1000000.0) # convert to microseconds
                tzhour = match.group('tzhour')
                if tzhour is not None:
                    tzhour = int(tzhour)
                else:
                    tzhour = 0
                tzminute = match.group('tzminute')
                if tzminute is not None:
                    tzminute = int(tzminute)
                else:
                    tzminute = 0
                self.value = datetime(year, month, day, hour, minute, second, fraction,
                                      Timezone(tzhour, tzminute))
            else:
                raise ValueError(
                    u'timestamp must be formatted as YAML ISO8601 variant or "YYYY-MM-DD": {0}'
                    .format(safe_repr(value)))

    @property
    def as_datetime_utc(self):
        return self.value.astimezone(UTC)

    @property
    def as_raw(self):
        return self.__str__()

    def __str__(self):
        the_datetime = self.as_datetime_utc
        return u'{0}{1}Z'.format(the_datetime.strftime(Timestamp.CANONICAL),
                                 Timestamp._fraction_as_str(the_datetime))

    def __repr__(self):
        return repr(self.__str__())

    def __eq__(self, timestamp):
        if not isinstance(timestamp, Timestamp):
            return False
        return self.value == timestamp.value

    def __lt__(self, timestamp):
        return self.value < timestamp.value

    @staticmethod
    def _fraction_as_str(the_datetime):
        return u'{0:g}'.format(the_datetime.microsecond / 1000000.0).lstrip('0')


@total_ordering
@implements_specification('3.2.2', 'tosca-simple-1.0')
class Version(object):
    """
    TOSCA supports the concept of "reuse" of type definitions, as well as template definitions which
    could be version and change over time. It is important to provide a reliable, normative means to
    represent a version string which enables the comparison and management of types and templates
    over time. Therefore, the TOSCA TC intends to provide a normative version type (string) for this
    purpose in future Working Drafts of this specification.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_VERSION>`__
    """

    REGEX = \
        r'^(?P<major>\d+)\.(?P<minor>\d+)(\.(?P<fix>\d+)' + \
        r'((\.(?P<qualifier>\w+))(\-(?P<build>\d+))?)?)?$'

    @staticmethod
    def key(version):
        """
        Key method for fast sorting.
        """
        return (version.major, version.minor, version.fix, version.qualifier, version.build)

    def __init__(self, entry_schema, constraints, value, aspect):                                   # pylint: disable=unused-argument
        str_value = unicode(value)
        match = re.match(Version.REGEX, str_value, flags=re.UNICODE)
        if match is None:
            raise ValueError(
                u'version must be formatted as <major_version>.<minor_version>'
                u'[.<fix_version>[.<qualifier>[-<build_version]]]: {0}'.format(safe_repr(value)))

        self.value = str_value

        self.major = match.group('major')
        self.major = int(self.major)
        self.minor = match.group('minor')
        self.minor = int(self.minor)
        self.fix = match.group('fix')
        if self.fix is not None:
            self.fix = int(self.fix)
        self.qualifier = match.group('qualifier')
        self.build = match.group('build')
        if self.build is not None:
            self.build = int(self.build)

    @property
    def as_raw(self):
        return self.value

    def __str__(self):
        return self.value

    def __repr__(self):
        return repr(self.__str__())

    def __eq__(self, version):
        if not isinstance(version, Version):
            return False
        return (self.major, self.minor, self.fix, self.qualifier, self.build) == \
            (version.major, version.minor, version.fix, version.qualifier, version.build)

    @implements_specification('3.2.2.1', 'tosca-simple-1.0')
    def __lt__(self, version):
        if self.major < version.major:
            return True
        elif self.major == version.major:
            if self.minor < version.minor:
                return True
            elif self.minor == version.minor:
                if self.fix < version.fix:
                    return True
                elif self.fix == version.fix:
                    if self.qualifier == version.qualifier:
                        if self.build < version.build:
                            return True
        return False


@implements_specification('3.2.3', 'tosca-simple-1.0')
class Range(object):
    """
    The range type can be used to define numeric ranges with a lower and upper boundary. For
    example, this allows for specifying a range of ports to be opened in a firewall.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_RANGE>`__
    """

    def __init__(self, entry_schema, constraints, value, aspect):                                   # pylint: disable=unused-argument
        if not isinstance(value, list):
            raise ValueError(u'range value is not a list: {0}'.format(safe_repr(value)))
        if len(value) != 2:
            raise ValueError(u'range value does not have exactly 2 elements: {0}'
                             .format(safe_repr(value)))

        def is_int(v):
            return isinstance(v, int) and (not isinstance(v, bool)) # In Python bool is an int

        if not is_int(value[0]):
            raise ValueError(u'lower bound of range is not a valid integer: {0}'
                             .format(safe_repr(value[0])))

        if value[1] != 'UNBOUNDED':
            if not is_int(value[1]):
                raise ValueError(u'upper bound of range is not a valid integer or "UNBOUNDED": {0}'
                                 .format(safe_repr(value[0])))

            if value[0] >= value[1]:
                raise ValueError(
                    u'upper bound of range is not greater than the lower bound: {0} >= {1}'
                    .format(safe_repr(value[0]), safe_repr(value[1])))

        self.value = value

    def is_in(self, value):
        if value < self.value[0]:
            return False
        if (self.value[1] != 'UNBOUNDED') and (value > self.value[1]):
            return False
        return True

    @property
    def as_raw(self):
        return list(self.value)


@implements_specification('3.2.4', 'tosca-simple-1.0')
class List(list):
    """
    The list type allows for specifying multiple values for a parameter of property. For example, if
    an application allows for being configured to listen on multiple ports, a list of ports could be
    configured using the list data type.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_LIST>`__
    """

    @staticmethod
    def _create(context, presentation, entry_schema, constraints, value, aspect):                   # pylint: disable=unused-argument
        if not isinstance(value, list):
            raise ValueError(u'"list" data type value is not a list: {0}'.format(safe_repr(value)))

        entry_schema_type = entry_schema._get_type(context)
        entry_schema_constraints = entry_schema.constraints

        the_list = List()
        for v in value:
            v = coerce_value(context, presentation, entry_schema_type, None,
                             entry_schema_constraints, v, aspect)
            if v is not None:
                the_list.append(v)

        return the_list

    # Can't define as property because it's old-style Python class
    def as_raw(self):
        return list(self)


@implements_specification('3.2.5', 'tosca-simple-1.0')
class Map(StrictDict):
    """
    The map type allows for specifying multiple values for a parameter of property as a map. In
    contrast to the list type, where each entry can only be addressed by its index in the list,
    entries in a map are named elements that can be addressed by their keys.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_MAP>`__
    """

    @staticmethod
    def _create(context, presentation, entry_schema, constraints, value, aspect):                   # pylint: disable=unused-argument
        if not isinstance(value, dict):
            raise ValueError(u'"map" data type value is not a dict: {0}'.format(safe_repr(value)))

        if entry_schema is None:
            raise ValueError(u'"map" data type does not define "entry_schema"')

        entry_schema_type = entry_schema._get_type(context)
        entry_schema_constraints = entry_schema.constraints

        the_map = Map()
        for k, v in value.iteritems():
            v = coerce_value(context, presentation, entry_schema_type, None,
                             entry_schema_constraints, v, aspect)
            if v is not None:
                the_map[k] = v

        return the_map

    def __init__(self, items=None):
        super(Map, self).__init__(items, key_class=basestring)

    # Can't define as property because it's old-style Python class
    def as_raw(self):
        return OrderedDict(self)


@total_ordering
@implements_specification('3.2.6', 'tosca-simple-1.0')
class Scalar(object):
    """
    The scalar-unit type can be used to define scalar values along with a unit from the list of
    recognized units.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_SCALAR_UNIT>`__
    """

    @staticmethod
    def key(scalar):
        """
        Key method for fast sorting.
        """
        return scalar.value

    def __init__(self, entry_schema, constraints, value, aspect):                                   # pylint: disable=unused-argument
        str_value = unicode(value)
        match = re.match(self.REGEX, str_value, flags=re.UNICODE)                                   # pylint: disable=no-member
        if match is None:
            raise ValueError(u'scalar must be formatted as <scalar> <unit>: {0}'
                             .format(safe_repr(value)))

        self.factor = float(match.group('scalar'))
        if self.factor < 0:
            raise ValueError('scalar is negative: {0}'.format(safe_repr(self.factor)))

        self.unit = match.group('unit')

        unit_lower = self.unit.lower()
        unit_size = None
        for k, v in self.UNITS.iteritems():                                                         # pylint: disable=no-member
            if k.lower() == unit_lower:
                self.unit = k
                unit_size = v
                break
        if unit_size is None:
            raise ValueError(u'scalar specified with unsupported unit: {0}'
                             .format(safe_repr(self.unit)))

        self.value = self.TYPE(self.factor * unit_size)                                             # pylint: disable=no-member

    @property
    def as_raw(self):
        return OrderedDict((
            ('value', self.value),
            ('factor', self.factor),
            ('unit', self.unit),
            ('unit_size', self.UNITS[self.unit])))                                                  # pylint: disable=no-member

    def __str__(self):
        return u'{0} {1}'.format(self.value, self.UNIT)                                             # pylint: disable=no-member

    def __repr__(self):
        return repr(self.__str__())

    def __eq__(self, scalar):
        if isinstance(scalar, Scalar):
            value = scalar.value
        else:
            value = self.TYPE(scalar)                                                               # pylint: disable=no-member
        return self.value == value

    def __lt__(self, scalar):
        if isinstance(scalar, Scalar):
            value = scalar.value
        else:
            value = self.TYPE(scalar)                                                               # pylint: disable=no-member
        return self.value < value


@implements_specification('3.2.6.4', 'tosca-simple-1.0')
class ScalarSize(Scalar):
    """
    Integer scalar for counting bytes.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_SCALAR_UNIT_SIZE>`__
    """

    # See: http://www.regular-expressions.info/floatingpoint.html
    REGEX = \
        r'^(?P<scalar>[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?)\s*(?P<unit>B|kB|KiB|MB|MiB|GB|GiB|TB|TiB)$'

    UNITS = {
        'B':               1,
        'kB':           1000,
        'KiB':          1024,
        'MB':        1000000,
        'MiB':       1048576,
        'GB':     1000000000,
        'GiB':    1073741824,
        'TB':  1000000000000,
        'TiB': 1099511627776}

    TYPE = int
    UNIT = 'bytes'


@implements_specification('3.2.6.5', 'tosca-simple-1.0')
class ScalarTime(Scalar):
    """
    Floating point scalar for counting seconds.

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_SCALAR_UNIT_TIME>`__
    """

    # See: http://www.regular-expressions.info/floatingpoint.html
    REGEX = r'^(?P<scalar>[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?)\s*(?P<unit>ns|us|ms|s|m|h|d)$'

    UNITS = {
        'ns':     0.000000001,
        'us':     0.000001,
        'ms':     0.001,
        's':      1.0,
        'm':     60.0,
        'h':   3600.0,
        'd':  86400.0}

    TYPE = float
    UNIT = 'seconds'


@implements_specification('3.2.6.6', 'tosca-simple-1.0')
class ScalarFrequency(Scalar):
    """
    Floating point scalar for counting cycles per second (Hz).

    See the `TOSCA Simple Profile v1.0 cos01 specification <http://docs.oasis-open.org/tosca
    /TOSCA-Simple-Profile-YAML/v1.0/cos01/TOSCA-Simple-Profile-YAML-v1.0-cos01.html
    #TYPE_TOSCA_SCALAR_UNIT_FREQUENCY>`__
    """

    # See: http://www.regular-expressions.info/floatingpoint.html
    REGEX = r'^(?P<scalar>[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?)\s*(?P<unit>Hz|kHz|MHz|GHz)$'

    UNITS = {
        'Hz':           1.0,
        'kHz':       1000.0,
        'MHz':    1000000.0,
        'GHz': 1000000000.0}

    TYPE = float
    UNIT = 'Hz'


#
# The following are hooked in the YAML as 'coerce_value' extensions
#

def coerce_timestamp(context, presentation, the_type, entry_schema, constraints, value, aspect):    # pylint: disable=unused-argument
    return coerce_to_data_type_class(context, presentation, Timestamp, entry_schema, constraints,
                                     value, aspect)


def coerce_version(context, presentation, the_type, entry_schema, constraints, value, aspect):      # pylint: disable=unused-argument
    return coerce_to_data_type_class(context, presentation, Version, entry_schema, constraints,
                                     value, aspect)


def coerce_range(context, presentation, the_type, entry_schema, constraints, value, aspect):
    if aspect == 'in_range':
        # When we're in a "in_range" constraint, the values are *not* themselves ranges, but numbers
        try:
            return float(value)
        except ValueError as e:
            report_issue_for_bad_format(context, presentation, the_type, value, aspect, e)
        except TypeError as e:
            report_issue_for_bad_format(context, presentation, the_type, value, aspect, e)
    else:
        return coerce_to_data_type_class(context, presentation, Range, entry_schema, constraints,
                                         value, aspect)


def coerce_list(context, presentation, the_type, entry_schema, constraints, value, aspect):         # pylint: disable=unused-argument
    return coerce_to_data_type_class(context, presentation, List, entry_schema, constraints,
                                     value, aspect)


def coerce_map_value(context, presentation, the_type, entry_schema, constraints, value, aspect):    # pylint: disable=unused-argument
    return coerce_to_data_type_class(context, presentation, Map, entry_schema, constraints, value,
                                     aspect)


def coerce_scalar_unit_size(context, presentation, the_type, entry_schema, constraints, value,      # pylint: disable=unused-argument
                            aspect):
    return coerce_to_data_type_class(context, presentation, ScalarSize, entry_schema, constraints,
                                     value, aspect)


def coerce_scalar_unit_time(context, presentation, the_type, entry_schema, constraints, value,      # pylint: disable=unused-argument
                            aspect):
    return coerce_to_data_type_class(context, presentation, ScalarTime, entry_schema, constraints,
                                     value, aspect)


def coerce_scalar_unit_frequency(context, presentation, the_type, entry_schema, constraints, value, # pylint: disable=unused-argument
                                 aspect):
    return coerce_to_data_type_class(context, presentation, ScalarFrequency, entry_schema,
                                     constraints, value, aspect)