from DateTime.DateTime import DateTime
from DateTime.DateTime import DateTimeError
from Products.CMFCore.utils import getToolByName
from Products.Five.browser import BrowserView
from time import localtime

CEILING = DateTime(9999, 0)
FLOOR = DateTime(1970, 0)
PLONE_CEILING = DateTime(2021, 0)  # 2020-12-31


def english_month_names():
    names = {}
    for x in range(1, 13):
        faux = DateTime(2004, x, 1)
        names[x] = faux.Month()
    return names

ENGLISH_MONTH_NAMES = english_month_names()


class DateComponents(BrowserView):
    """A view that provides some helper methods useful in date widgets.
    """

    def result(self, date=None,
               use_ampm=False,
               starting_year=None,
               ending_year=None,
               future_years=None,
               minute_step=5):
        """Returns a dict with date information.
        """
        ptool = getToolByName(self.context, 'portal_properties')
        site_props = getattr(ptool, 'site_properties', None)

        # Get the date format from the locale
        dates = self.request.locale.dates

        timepattern = dates.getFormatter('time').getPattern()
        if 'a' in timepattern:
            use_ampm = True
        month_names = dates.getFormatter('date').calendar.months

        # 'id' is what shows up.  December for month 12.
        # 'value' is the value for the form.
        # 'selected' is whether or not it is selected.

        default = 0
        years = []
        days = []
        months = []
        hours = []
        minutes = []
        ampm = []
        now = DateTime()

        if isinstance(date, basestring):
            date = date.strip()
            if not date:
                date = None
            else:
                # Please see datecomponents.txt for an explanation of
                # the next few lines. Also see #11423
                dateParts = date.split(" ")
                dateParts[0] = dateParts[0].replace("-", "/")
                date = ' '.join(dateParts)

        if date is None:
            date = now
            default = 1
        elif not isinstance(date, DateTime):
            try:
                date = DateTime(date)
            except (TypeError, DateTimeError):
                date = now
                default = 1

        # Anything above PLONE_CEILING should be PLONE_CEILING
        if date.greaterThan(PLONE_CEILING):
            date = PLONE_CEILING

        # Represent the date in the local timezone
        try:
            local_zone = date.localZone(localtime(date.timeTime()))
        except ValueError:
            # Dates before 1970 use a negative timeTime() value, which on
            # on some platforms are not handled well and lead to a ValueError.
            # In those cases, calculate the local timezone (which is DST based)
            # from the same date in the *current year* instead. This is better
            # than failing altogether!
            timeZoneDate = DateTime(localtime().tm_year, *date.parts()[1:])
            local_zone = date.localZone(localtime(timeZoneDate.timeTime()))
        date = date.toZone(local_zone)

        # Get portal year range
        min_year = starting_year
        if starting_year is None and site_props is not None:
            min_year = site_props.getProperty('calendar_starting_year', 1999)
        else:
            min_year = int(starting_year or 1999)
        if ending_year is None:
            if future_years is None and site_props is not None:
                future_years = site_props.getProperty('calendar_future_years_available', 5)
            else:
                future_years = int(future_years or 5)
            max_year = int(future_years) + now.year()
        else:
            max_year = int(ending_year)

        # keeps the existing date if it's out of range
        if not default:
            if min_year > date.year():
                min_year = date.year()
            if max_year < date.year():
                max_year = date.year()

        year = date.year()

        if default:
            years.append({'id': '--', 'value': '0000', 'selected': 1})
        else:
            years.append({'id': '--', 'value': '0000', 'selected': None})

        for x in range(min_year, max_year+1):
            d = {'id': x, 'value': x, 'selected': None}
            if x == year and not default:
                d['selected'] = 1
            years.append(d)

        month = date.month()

        if default:
            months.append({'id': '--', 'value': '00', 'selected': 1, 'title': '--'})
        else:
            months.append({'id': '--', 'value': '00', 'selected': None, 'title': '--'})

        for x in range(1, 13):
            d = {'id': ENGLISH_MONTH_NAMES[x], 'value': '%02d' % x, 'selected': None}
            if x == month and not default:
                d['selected'] = 1
            d['title'] = month_names[x][0]
            months.append(d)

        day = date.day()

        if default:
            days.append({'id': '--', 'value': '00', 'selected': 1})
        else:
            days.append({'id': '--', 'value': '00', 'selected': None})

        for x in range(1, 32):
            d = {'id': x, 'value': '%02d' % x, 'selected': None}
            if x == day and not default:
                d['selected'] = 1
            days.append(d)

        if use_ampm:
            hours_range = [12] + range(1, 12)
            hour_default = '12'
            hour = int(date.h_12())
        else:
            hours_range = range(0, 24)
            hour_default = '00'
            hour = int(date.h_24())
        
        if default:
            hours.append({'id': '--', 'value': hour_default, 'selected': 1})
        else:
            hours.append({'id': '--', 'value': hour_default, 'selected': None})

        for x in hours_range:
            d = {'id': '%02d' % x, 'value': '%02d' % x, 'selected': None}
            if x == hour and not default:
                d['selected'] = 1
            hours.append(d)

        if default:
            minutes.append({'id': '--', 'value': '00', 'selected': 1})
        else:
            minutes.append({'id': '--', 'value': '00', 'selected': None})

        minute = date.minute()

        if minute_step is None:
            minute_step = 5

        if minute + minute_step >= 60:
            # edge case. see doctest for explanation
            minute = 60 - minute_step

        for x in range(0, 60, minute_step):
            d = {'id': '%02d' % x, 'value': '%02d' % x, 'selected': None}
            if (x == minute or minute < x < minute + minute_step) and not default:
                d['selected'] = 1
            minutes.append(d)

        if use_ampm:
            p = date.strftime('%p')

            if default:
                ampm.append({'id': '--', 'value': 'AM', 'selected': 1})
            else:
                ampm.append({'id': '--', 'value': 'AM', 'selected': None})

            for x in ('AM', 'PM'):
                d = {'id': x, 'value': x, 'selected': None}
                if x == p and not default:
                    d['selected'] = 1
                ampm.append(d)

        return {'years': years, 'months': months, 'days': days,
                'hours': hours, 'minutes': minutes, 'ampm': ampm}
