#
# spyne - Copyright (C) Spyne contributors.
#
# This library 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 2.1 of the License, or (at your option) any later version.
#
# This library 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 this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
#

from __future__ import print_function

import logging
logger = logging.getLogger(__name__)

import re
import pytz
import uuid

from math import modf
from time import strptime, mktime
from datetime import timedelta, time, datetime, date
from decimal import Decimal as D, InvalidOperation

from pytz import FixedOffset

try:
    from lxml import etree
    from lxml import html
except ImportError:
    etree = None
    html = None

from spyne.protocol._base import ProtocolMixin
from spyne.model import ModelBase, XmlAttribute, Array, Null, \
    ByteArray, File, ComplexModelBase, AnyXml, AnyHtml, Unicode, String, \
    Decimal, Double, Integer, Time, DateTime, Uuid, Date, Duration, Boolean, Any

from spyne.error import ValidationError

from spyne.model.binary import binary_decoding_handlers, BINARY_ENCODING_USE_DEFAULT

from spyne.util import six
from spyne.model.enum import EnumBase
from spyne.model.primitive.datetime import TIME_PATTERN, DATE_PATTERN

from spyne.util.cdict import cdict


_date_re = re.compile(DATE_PATTERN)
_time_re = re.compile(TIME_PATTERN)
_duration_re = re.compile(
        r'(?P<sign>-?)'
        r'P'
        r'(?:(?P<years>\d+)Y)?'
        r'(?:(?P<months>\d+)M)?'
        r'(?:(?P<days>\d+)D)?'
        r'(?:T(?:(?P<hours>\d+)H)?'
        r'(?:(?P<minutes>\d+)M)?'
        r'(?:(?P<seconds>\d+(.\d+)?)S)?)?'
    )


class InProtocolBase(ProtocolMixin):
    """This is the abstract base class for all input protocol implementations.
    Child classes can implement only the required subset of the public methods.

    An output protocol must implement :func:`serialize` and
    :func:`create_out_string`.

    An input protocol must implement :func:`create_in_document`,
    :func:`decompose_incoming_envelope` and :func:`deserialize`.

    The ProtocolBase class supports the following events:

    * ``before_deserialize``:
      Called before the deserialization operation is attempted.

    * ``after_deserialize``:
      Called after the deserialization operation is finished.

    The arguments the constructor takes are as follows:

    :param app: The application this protocol belongs to.
    :param mime_type: The mime_type this protocol should set for transports
        that support this. This is a quick way to override the mime_type by
        default instead of subclassing the releavant protocol implementation.
    """

    def __init__(self, app=None, validator=None, mime_type=None,
             ignore_wrappers=False, binary_encoding=None, string_encoding=None):

        self.validator = None

        super(InProtocolBase, self).__init__(app=app, mime_type=mime_type,
            ignore_wrappers=ignore_wrappers,
               binary_encoding=binary_encoding, string_encoding=string_encoding)

        self.message = None
        self.validator = None
        self.set_validator(validator)

        if mime_type is not None:
            self.mime_type = mime_type

        fsh = {
            Any: self.any_from_bytes,
            Null: self.null_from_bytes,
            File: self.file_from_bytes,
            Array: self.array_from_bytes,
            Double: self.double_from_bytes,
            String: self.string_from_bytes,
            AnyXml: self.any_xml_from_bytes,
            Boolean: self.boolean_from_bytes,
            Integer: self.integer_from_bytes,
            Unicode: self.unicode_from_bytes,
            AnyHtml: self.any_html_from_bytes,
            ByteArray: self.byte_array_from_bytes,
            EnumBase: self.enum_base_from_bytes,
            ModelBase: self.model_base_from_bytes,
            XmlAttribute: self.xmlattribute_from_bytes,
            ComplexModelBase: self.complex_model_base_from_bytes
        }

        self._from_bytes_handlers = cdict(fsh)
        self._from_unicode_handlers = cdict(fsh)

        self._from_bytes_handlers[Date] = self.date_from_bytes
        self._from_bytes_handlers[Time] = self.time_from_bytes
        self._from_bytes_handlers[Uuid] = self.uuid_from_bytes
        self._from_bytes_handlers[Decimal] = self.decimal_from_bytes
        self._from_bytes_handlers[DateTime] = self.datetime_from_bytes
        self._from_bytes_handlers[Duration] = self.duration_from_bytes

        self._from_unicode_handlers[Date] = self.date_from_unicode
        self._from_unicode_handlers[Uuid] = self.uuid_from_unicode
        self._from_unicode_handlers[Time] = self.time_from_unicode
        self._from_unicode_handlers[Decimal] = self.decimal_from_unicode
        self._from_unicode_handlers[DateTime] = self.datetime_from_unicode
        self._from_unicode_handlers[Duration] = self.duration_from_unicode


        self._datetime_dsmap = {
            None: self._datetime_from_unicode,
            'sec': self._datetime_from_sec,
            'sec_float': self._datetime_from_sec_float,
            'msec': self._datetime_from_msec,
            'msec_float': self._datetime_from_msec_float,
            'usec': self._datetime_from_usec,
        }

    def _datetime_from_sec(self, cls, value):
        try:
            return datetime.fromtimestamp(value)
        except TypeError:
            logger.error("Invalid value %r", value)
            raise

    def _datetime_from_sec_float(self, cls, value):
        try:
            return datetime.fromtimestamp(value)
        except TypeError:
            logger.error("Invalid value %r", value)
            raise

    def _datetime_from_msec(self, cls, value):
        try:
            return datetime.fromtimestamp(value // 1000)
        except TypeError:
            logger.error("Invalid value %r", value)
            raise

    def _datetime_from_msec_float(self, cls, value):
        try:
            return datetime.fromtimestamp(value / 1000)
        except TypeError:
            logger.error("Invalid value %r", value)
            raise

    def _datetime_from_usec(self, cls, value):
        try:
            return datetime.fromtimestamp(value / 1e6)
        except TypeError:
            logger.error("Invalid value %r", value)
            raise

    def create_in_document(self, ctx, in_string_encoding=None):
        """Uses ``ctx.in_string`` to set ``ctx.in_document``."""

    def decompose_incoming_envelope(self, ctx, message):
        """Sets the ``ctx.method_request_string``, ``ctx.in_body_doc``,
        ``ctx.in_header_doc`` and ``ctx.service`` properties of the ctx object,
        if applicable.
        """

    def deserialize(self, ctx, message):
        """Takes a MethodContext instance and a string containing ONE document
        instance in the ``ctx.in_string`` attribute.

        Returns the corresponding native python object in the ctx.in_object
        attribute.
        """

    def validate_document(self, payload):
        """Method to be overriden to perform any sort of custom input
        validation on the parsed input document.
        """

    def set_validator(self, validator):
        """You must override this function if you want your protocol to support
        validation."""

        assert validator is None

        self.validator = None

    def from_bytes(self, class_, string, *args, **kwargs):
        if string is None:
            return None

        if isinstance(string, six.string_types) and \
                           len(string) == 0 and class_.Attributes.empty_is_none:
            return None

        handler = self._from_bytes_handlers[class_]
        return handler(class_, string, *args, **kwargs)

    def from_unicode(self, class_, string, *args, **kwargs):
        if string is None:
            return None

        #if not six.PY2:
        #    assert isinstance(string, str), \
        #        "Invalid type passed to `from_unicode`: {}".format(
        #                                         (class_, type(string), string))

        cls_attrs = self.get_cls_attrs(class_)

        if isinstance(string, six.string_types) and len(string) == 0 and \
                                                        cls_attrs.empty_is_none:
            return None

        handler = self._from_unicode_handlers[class_]
        return handler(class_, string, *args, **kwargs)

    def null_from_bytes(self, cls, value):
        return None

    def any_from_bytes(self, cls, value):
        return value

    def any_xml_from_bytes(self, cls, string):
        try:
            return etree.fromstring(string)
        except etree.XMLSyntaxError as e:
            raise ValidationError(string, "%%r: %r" % e)

    def any_html_from_bytes(self, cls, string):
        try:
            return html.fromstring(string)
        except etree.ParserError as e:
            if e.args[0] == "Document is empty":
                pass
            else:
                raise

    def uuid_from_unicode(self, cls, string, suggested_encoding=None):
        attr = self.get_cls_attrs(cls)
        ser_as = attr.serialize_as
        encoding = attr.encoding

        if encoding is None:
            encoding = suggested_encoding

        retval = string

        if ser_as in ('bytes', 'bytes_le'):
            retval, = binary_decoding_handlers[encoding](string)

        try:
            retval = _uuid_deserialize[ser_as](retval)
        except (ValueError, TypeError, UnicodeDecodeError) as e:
            raise ValidationError(e)

        return retval

    def uuid_from_bytes(self, cls, string, suggested_encoding=None, **_):
        attr = self.get_cls_attrs(cls)
        ser_as = attr.serialize_as
        encoding = attr.encoding

        if encoding is None:
            encoding = suggested_encoding

        retval = string

        if ser_as in ('bytes', 'bytes_le'):
            retval, = binary_decoding_handlers[encoding](string)
        elif isinstance(string, six.binary_type):
            retval = string.decode('ascii')

        try:
            retval = _uuid_deserialize[ser_as](retval)
        except ValueError as e:
            raise ValidationError(e)

        return retval

    def unicode_from_bytes(self, cls, value):
        retval = value

        if isinstance(value, six.binary_type):
            cls_attrs = self.get_cls_attrs(cls)

            if cls_attrs.encoding is not None:
                retval = six.text_type(value, cls_attrs.encoding,
                                                errors=cls_attrs.unicode_errors)

            elif self.string_encoding is not None:
                retval = six.text_type(value, self.string_encoding,
                                                errors=cls_attrs.unicode_errors)

            else:
                retval = six.text_type(value, errors=cls_attrs.unicode_errors)

        return retval

    def string_from_bytes(self, cls, value):
        retval = value
        cls_attrs = self.get_cls_attrs(cls)
        if isinstance(value, six.text_type):
            if cls_attrs.encoding is None:
                raise Exception("You need to define a source encoding for "
                                "decoding incoming unicode values.")
            else:
                retval = value.encode(cls_attrs.encoding)

        return retval

    def decimal_from_unicode(self, cls, string):
        cls_attrs = self.get_cls_attrs(cls)
        if cls_attrs.max_str_len is not None and len(string) > \
                                                     cls_attrs.max_str_len:
            raise ValidationError(string, "Decimal %%r longer than %d "
                                          "characters" % cls_attrs.max_str_len)

        try:
            return D(string)
        except InvalidOperation as e:
            raise ValidationError(string, "%%r: %r" % e)

    def decimal_from_bytes(self, cls, string):
        return self.decimal_from_unicode(cls,
                                    string.decode(self.default_string_encoding))

    def double_from_bytes(self, cls, string):
        try:
            return float(string)
        except (TypeError, ValueError) as e:
            raise ValidationError(string, "%%r: %r" % e)

    def integer_from_bytes(self, cls, string):
        cls_attrs = self.get_cls_attrs(cls)

        if isinstance(string, (six.text_type, six.binary_type)) and \
                                    cls_attrs.max_str_len is not None and \
                                    len(string) > cls_attrs.max_str_len:
            raise ValidationError(string,
                                         "Integer %%r longer than %d characters"
                                                        % cls_attrs.max_str_len)

        try:
            return int(string)
        except ValueError:
            raise ValidationError(string, "Could not cast %r to integer")

    def time_from_unicode(self, cls, string):
        """Expects ISO formatted times."""

        match = _time_re.match(string)
        if match is None:
            raise ValidationError(string, "%%r does not match regex %r " %
                                                               _time_re.pattern)

        fields = match.groupdict(0)
        microsec = fields.get('sec_frac')
        if microsec is None or microsec == 0:
            microsec = 0
        else:
            microsec = min(999999, int(round(float(microsec) * 1e6)))

        return time(int(fields['hr']), int(fields['min']),
                                                   int(fields['sec']), microsec)

    def time_from_bytes(self, cls, string):
        if isinstance(string, six.binary_type):
            string = string.decode(self.default_string_encoding)

        return self.time_from_unicode(cls, string)

    def date_from_unicode_iso(self, cls, string):
        """This is used by protocols like SOAP who need ISO8601-formatted dates
        no matter what.
        """

        try:
            return date(*(strptime(string, u'%Y-%m-%d')[0:3]))

        except ValueError:
            match = cls._offset_re.match(string)

            if match:
                year = int(match.group('year'))
                month = int(match.group('month'))
                day = int(match.group('day'))

                return date(year, month, day)

            raise ValidationError(string)

    def enum_base_from_bytes(self, cls, value):
        if self.validator is self.SOFT_VALIDATION and not (
                                        cls.validate_string(cls, value)):
            raise ValidationError(value)
        return getattr(cls, value)

    def model_base_from_bytes(self, cls, value):
        return cls.from_bytes(value)

    def datetime_from_unicode_iso(self, cls, string):
        astz = self.get_cls_attrs(cls).as_timezone

        match = cls._utc_re.match(string)
        if match:
            tz = pytz.utc
            retval = _parse_datetime_iso_match(match, tz=tz)
            if astz is not None:
                retval = retval.astimezone(astz)
            return retval

        if match is None:
            match = cls._offset_re.match(string)
            if match:
                tz_hr, tz_min = [int(match.group(x))
                                                   for x in ("tz_hr", "tz_min")]
                tz = FixedOffset(tz_hr * 60 + tz_min, {})
                retval = _parse_datetime_iso_match(match, tz=tz)
                if astz is not None:
                    retval = retval.astimezone(astz)
                return retval

        if match is None:
            match = cls._local_re.match(string)
            if match:
                retval = _parse_datetime_iso_match(match)
                if astz:
                    retval = retval.replace(tzinfo=astz)
                return retval

        raise ValidationError(string)

    def datetime_from_unicode(self, cls, string):
        serialize_as = self.get_cls_attrs(cls).serialize_as
        return self._datetime_dsmap[serialize_as](cls, string)

    def datetime_from_bytes(self, cls, string):
        if isinstance(string, six.binary_type):
            string = string.decode(self.default_string_encoding)

        serialize_as = self.get_cls_attrs(cls).serialize_as
        return self._datetime_dsmap[serialize_as](cls, string)

    def date_from_bytes(self, cls, string):
        if isinstance(string, six.binary_type):
            string = string.decode(self.default_string_encoding)

        date_format = self._get_date_format(self.get_cls_attrs(cls))
        try:
            if date_format is not None:
                dt = datetime.strptime(string, date_format)
                return date(dt.year, dt.month, dt.day)

            return self.date_from_unicode_iso(cls, string)

        except ValueError as e:
            match = cls._offset_re.match(string)
            if match:
                return date(int(match.group('year')),
                            int(match.group('month')), int(match.group('day')))
            else:
                raise ValidationError(string,
                                         "%%r: %s" % repr(e).replace("%", "%%"))

    def date_from_unicode(self, cls, string):
        date_format = self._get_date_format(self.get_cls_attrs(cls))
        try:
            if date_format is not None:
                dt = datetime.strptime(string, date_format)
                return date(dt.year, dt.month, dt.day)

            return self.date_from_unicode_iso(cls, string)

        except ValueError as e:
            match = cls._offset_re.match(string)
            if match:
                return date(int(match.group('year')),
                            int(match.group('month')), int(match.group('day')))
            else:
                # the message from ValueError is quite nice already
                raise ValidationError(e.message, "%s")

    def duration_from_unicode(self, cls, string):
        duration = _duration_re.match(string).groupdict(0)
        if duration is None:
            raise ValidationError(string,
                "Time data '%%s' does not match regex '%s'" %
                                                        (_duration_re.pattern,))

        days = int(duration['days'])
        days += int(duration['months']) * 30
        days += int(duration['years']) * 365
        hours = int(duration['hours'])
        minutes = int(duration['minutes'])
        seconds = float(duration['seconds'])
        f, i = modf(seconds)
        seconds = i
        microseconds = int(1e6 * f)

        delta = timedelta(days=days, hours=hours, minutes=minutes,
            seconds=seconds, microseconds=microseconds)

        if duration['sign'] == "-":
            delta *= -1

        return delta

    def duration_from_bytes(self, cls, string):
        if isinstance(string, six.binary_type):
            string = string.decode(self.default_string_encoding)

        return self.duration_from_unicode(cls, string)

    def boolean_from_bytes(self, cls, string):
        return string.lower() in ('true', '1')

    def byte_array_from_bytes(self, cls, value, suggested_encoding=None):
        encoding = self.get_cls_attrs(cls).encoding
        if encoding is BINARY_ENCODING_USE_DEFAULT:
            encoding = suggested_encoding
        return binary_decoding_handlers[encoding](value)

    def file_from_bytes(self, cls, value, suggested_encoding=None):
        encoding = self.get_cls_attrs(cls).encoding
        if encoding is BINARY_ENCODING_USE_DEFAULT:
            encoding = suggested_encoding

        return File.Value(data=binary_decoding_handlers[encoding](value))

    def complex_model_base_from_bytes(self, cls, string, **_):
        raise TypeError("Only primitives can be deserialized from string.")

    def array_from_bytes(self, cls, string, **_):
        if self.get_cls_attrs(cls).serialize_as != 'sd-list':
            raise TypeError("Only primitives can be deserialized from string.")

        # sd-list being space-delimited list.
        retval = []
        inner_type, = cls._type_info.values()
        for s in string.split():
            retval.append(self.from_bytes(inner_type, s))

        return retval

    def xmlattribute_from_bytes(self, cls, value):
        return self.from_bytes(cls.type, value)

    def _datetime_from_unicode(self, cls, string):
        cls_attrs = self.get_cls_attrs(cls)

        # get parser
        parser = cls_attrs.parser

        # get date_format
        dt_format = cls_attrs.dt_format
        if dt_format is None:
            dt_format = cls_attrs.date_format
        if dt_format is None:
            dt_format = cls_attrs.out_format
        if dt_format is None:
            dt_format = cls_attrs.format

        # parse the string
        if parser is not None:
            retval = parser(self, cls, string)

        elif dt_format is not None:
            if six.PY2:
                # FIXME: perhaps it should encode to string's encoding instead
                # of utf8 all the time
                if isinstance(dt_format, six.text_type):
                    dt_format = dt_format.encode('utf8')
                if isinstance(string, six.text_type):
                    string = string.encode('utf8')

            retval = datetime.strptime(string, dt_format)

            astz = cls_attrs.as_timezone
            if astz:
                retval = retval.astimezone(cls_attrs.as_time_zone)

        else:
            retval = self.datetime_from_unicode_iso(cls, string)

        return retval


_uuid_deserialize = {
    None: lambda s: uuid.UUID(s.decode('ascii') if isinstance(s, bytes) else s),
    'hex': lambda s: uuid.UUID(hex=s),
    'urn': lambda s: uuid.UUID(hex=s),
    'bytes': lambda s: uuid.UUID(bytes=s),
    'bytes_le': lambda s: uuid.UUID(bytes_le=s),
    'fields': lambda s: uuid.UUID(fields=s),
    'int': lambda s: uuid.UUID(int=s),
    ('int', int): lambda s: uuid.UUID(int=s),
    ('int', str): lambda s: uuid.UUID(int=int(s)),
}

if six.PY2:
    _uuid_deserialize[None] = lambda s: uuid.UUID(s)
    _uuid_deserialize[('int', long)] = _uuid_deserialize[('int', int)]


def _parse_datetime_iso_match(date_match, tz=None):
    fields = date_match.groupdict()

    year = int(fields.get('year'))
    month = int(fields.get('month'))
    day = int(fields.get('day'))
    hour = int(fields.get('hr'))
    minute = int(fields.get('min'))
    second = int(fields.get('sec'))
    usecond = fields.get("sec_frac")
    if usecond is None:
        usecond = 0
    else:
        # we only get the most significant 6 digits because that's what
        # datetime can handle.
        usecond = min(999999, int(round(float(usecond) * 1e6)))

    return datetime(year, month, day, hour, minute, second, usecond, tz)


_dt_sec = lambda cls, val: \
        int(mktime(val.timetuple()))
_dt_sec_float = lambda cls, val: \
        mktime(val.timetuple()) + (val.microsecond / 1e6)

_dt_msec = lambda cls, val: \
        int(mktime(val.timetuple())) * 1000 + (val.microsecond // 1000)
_dt_msec_float = lambda cls, val: \
        mktime(val.timetuple()) * 1000 + (val.microsecond / 1000.0)

_dt_usec = lambda cls, val: \
        int(mktime(val.timetuple())) * 1000000 + val.microsecond

_datetime_smap = {
    'sec': _dt_sec,
    'secs': _dt_sec,
    'second': _dt_sec,
    'seconds': _dt_sec,

    'sec_float': _dt_sec_float,
    'secs_float': _dt_sec_float,
    'second_float': _dt_sec_float,
    'seconds_float': _dt_sec_float,

    'msec': _dt_msec,
    'msecs': _dt_msec,
    'msecond': _dt_msec,
    'mseconds': _dt_msec,
    'millisecond': _dt_msec,
    'milliseconds': _dt_msec,

    'msec_float': _dt_msec_float,
    'msecs_float': _dt_msec_float,
    'msecond_float': _dt_msec_float,
    'mseconds_float': _dt_msec_float,
    'millisecond_float': _dt_msec_float,
    'milliseconds_float': _dt_msec_float,

    'usec': _dt_usec,
    'usecs': _dt_usec,
    'usecond': _dt_usec,
    'useconds': _dt_usec,
    'microsecond': _dt_usec,
    'microseconds': _dt_usec,
}


def _file_to_iter(f):
    try:
        data = f.read(65536)
        while len(data) > 0:
            yield data
            data = f.read(65536)

    finally:
        f.close()