import datetime

from django.forms.widgets import Widget

class DatePickerWidget(Widget):
    template_name = 'widgets/date-picker.html'

    n_weeks = 5

    def get_context(self, name, value, attrs):
        context = super().get_context(name, value, attrs)

        # get first day of the week
        today = datetime.date.today()
        context['widget']['today'] = today
        first_day_of_week = today - datetime.timedelta(days=today.weekday())
        
        # get the weekdays
        weekdays = []
        for i in range(7):
            weekdays.append((first_day_of_week + datetime.timedelta(days=i)).strftime('%A')[0])
        context['widget']['weekdays'] = weekdays

        # for the next weeks
        weeks = []
        for i in range(self.n_weeks):
                date = first_day_of_week + datetime.timedelta(days=i*7)
                week = {
                    'days': [],
                    'month': date.strftime('%b'),
                    'year': date.strftime('%Y'),
                }
                for j in range(7):
                    day = {
                        'date': date + datetime.timedelta(days=j),
                        'day': (date + datetime.timedelta(days=j)).strftime('%d'),
                    }
                    week['days'].append(day)
                weeks.append(week)

        context['widget']['weeks'] = weeks

        return context
    
    def value_from_datadict(self, data, files, name):
        dates = []
        for day in self.GetValidDates():
            if data.get(f"date_{day.strftime('%Y-%m-%d')}") == "on":
                dates.append(day)
        return dates

    def value_omitted_from_data(self, data, files, name):
        return not any(
            (data.get(f"date_{day.strftime('%Y-%m-%d')}") == "on")
            for day in self.GetValidDates()
        )

    def GetValidDates(self):
        today = datetime.date.today()
        return [
            (today + datetime.timedelta(days=i))
            for i in range(7*self.n_weeks)
        ]