import time
import datetime

from flask.ext.admin._compat import text_type
from flask.ext.admin.babel import lazy_gettext


class BaseFilter(object):
    """
        Base filter class.
    """
    def __init__(self, name, options=None, data_type=None):
        """
            Constructor.

            :param name:
                Displayed name
            :param options:
                List of fixed options. If provided, will use drop down instead of textbox.
            :param data_type:
                Client-side widget type to use.
        """
        self.name = name
        self.options = options
        self.data_type = data_type

    def get_options(self, view):
        """
            Return list of predefined options.

            Override to customize behavior.

            :param view:
                Associated administrative view class.
        """
        options = self.options

        if options:
            if callable(options):
                options = options()

            return [(v, text_type(n)) for v, n in options]

        return None

    def validate(self, value):
        """
            Validate value.

            If value is valid, returns `True` and `False` otherwise.

            :param value:
                Value to validate
        """
        # useful for filters with date conversions, see if conversion in clean() raises ValueError
        try:
            self.clean(value)
            return True
        except ValueError:
            return False

    def clean(self, value):
        """
            Parse value into python format. Occurs before .apply()

            :param value:
                Value to parse
        """
        return value

    def apply(self, query):
        """
            Apply search criteria to the query and return new query.

            :param query:
                Query
        """
        raise NotImplementedError()

    def operation(self):
        """
            Return readable operation name.

            For example: u'equals'
        """
        raise NotImplementedError()

    def __unicode__(self):
        return self.name


# Customized filters
class BaseBooleanFilter(BaseFilter):
    """
        Base boolean filter, uses fixed list of options.
    """
    def __init__(self, name, options=None, data_type=None):
        super(BaseBooleanFilter, self).__init__(name,
                                                (('1', lazy_gettext(u'Yes')),
                                                 ('0', lazy_gettext(u'No'))),
                                                data_type)

    def validate(self, value):
        return value in ('0', '1')


class BaseIntFilter(BaseFilter):
    """
        Base Int filter. Adds validation and changes value to python int.
    """
    def clean(self, value):
        return int(float(value))


class BaseFloatFilter(BaseFilter):
    """
        Base Float filter. Adds validation and changes value to python float.
    """
    def clean(self, value):
        return float(value)


class BaseIntListFilter(BaseFilter):
    """
        Base Integer list filter. Adds validation for int "In List" filter.
    """
    def clean(self, value):
        return [int(float(v.strip())) for v in value.split(',') if v.strip()]


class BaseFloatListFilter(BaseFilter):
    """
        Base Float list filter. Adds validation for float "In List" filter.
    """
    def clean(self, value):
        return [float(v.strip()) for v in value.split(',') if v.strip()]


class BaseDateFilter(BaseFilter):
    """
        Base Date filter. Uses client-side date picker control.
    """
    def __init__(self, name, options=None, data_type=None):
        super(BaseDateFilter, self).__init__(name,
                                             options,
                                             data_type='datepicker')

    def clean(self, value):
        return datetime.datetime.strptime(value, '%Y-%m-%d').date()


class BaseDateBetweenFilter(BaseFilter):
    """
        Base Date Between filter. Consolidates logic for validation and clean.
        Apply method is different for each back-end.
    """
    def clean(self, value):
        return [datetime.datetime.strptime(range, '%Y-%m-%d')
                for range in value.split(' to ')]

    def operation(self):
        return lazy_gettext('between')

    def validate(self, value):
        try:
            value = [datetime.datetime.strptime(range, '%Y-%m-%d')
                     for range in value.split(' to ')]
            # if " to " is missing, fail validation
            # sqlalchemy's .between() will not work if end date is before start date
            if (len(value) == 2) and (value[0] <= value[1]):
                return True
            else:
                return False
        except ValueError:
            return False


class BaseDateTimeFilter(BaseFilter):
    """
        Base DateTime filter. Uses client-side date time picker control.
    """
    def __init__(self, name, options=None, data_type=None):
        super(BaseDateTimeFilter, self).__init__(name,
                                                 options,
                                                 data_type='datetimepicker')

    def clean(self, value):
        # datetime filters will not work in SQLite + SQLAlchemy if value not converted to datetime
        return datetime.datetime.strptime(value, '%Y-%m-%d %H:%M:%S')


class BaseDateTimeBetweenFilter(BaseFilter):
    """
        Base DateTime Between filter. Consolidates logic for validation and clean.
        Apply method is different for each back-end.
    """
    def clean(self, value):
        return [datetime.datetime.strptime(range, '%Y-%m-%d %H:%M:%S')
                for range in value.split(' to ')]

    def operation(self):
        return lazy_gettext('between')

    def validate(self, value):
        try:
            value = [datetime.datetime.strptime(range, '%Y-%m-%d %H:%M:%S')
                     for range in value.split(' to ')]
            if (len(value) == 2) and (value[0] <= value[1]):
                return True
            else:
                return False
        except ValueError:
            return False


class BaseTimeFilter(BaseFilter):
    """
        Base Time filter. Uses client-side time picker control.
    """
    def __init__(self, name, options=None, data_type=None):
        super(BaseTimeFilter, self).__init__(name,
                                             options,
                                             data_type='timepicker')

    def clean(self, value):
        # time filters will not work in SQLite + SQLAlchemy if value not converted to time
        timetuple = time.strptime(value, '%H:%M:%S')
        return datetime.time(timetuple.tm_hour,
                             timetuple.tm_min,
                             timetuple.tm_sec)


class BaseTimeBetweenFilter(BaseFilter):
    """
        Base Time Between filter. Consolidates logic for validation and clean.
        Apply method is different for each back-end.
    """
    def clean(self, value):
        timetuples = [time.strptime(range, '%H:%M:%S')
                      for range in value.split(' to ')]
        return [datetime.time(timetuple.tm_hour,
                              timetuple.tm_min,
                              timetuple.tm_sec)
                              for timetuple in timetuples]

    def operation(self):
        return lazy_gettext('between')

    def validate(self, value):
        try:
            timetuples = [time.strptime(range, '%H:%M:%S')
                          for range in value.split(' to ')]
            if (len(timetuples) == 2) and (timetuples[0] <= timetuples[1]):
                return True
            else:
                return False
        except ValueError:
            raise
            return False


def convert(*args):
    """
        Decorator for field to filter conversion routine.

        See :mod:`flask.ext.admin.contrib.sqla.filters` for usage example.
    """
    def _inner(func):
        func._converter_for = map(str.lower, args)
        return func
    return _inner


class BaseFilterConverter(object):
    """
        Base filter converter.

        Derive from this class to implement custom field to filter conversion
        logic.
    """
    def __init__(self):
        self.converters = dict()

        for p in dir(self):
            attr = getattr(self, p)

            if hasattr(attr, '_converter_for'):
                for p in attr._converter_for:
                    self.converters[p] = attr
