# -*- coding: utf-8 -*-
from django.utils import timezone
from django.db.models import Sum

KFET_WAKES_UP_AT = 7

# donne le nom des jours d'une liste de dates
# dans un dico ordonné
def daynames(dates):
    names = {}
    for i in dates:
        names[i] = dates[i].strftime("%A")
    return names


# donne le nom des semaines une liste de dates
# dans un dico ordonné
def weeknames(dates):
    names = {}
    for i in dates:
        names[i] = dates[i].strftime("Semaine %W")
    return names


# donne le nom des mois d'une liste de dates
# dans un dico ordonné
def monthnames(dates):
    names = {}
    for i in dates:
        names[i] = dates[i].strftime("%B")
    return names


# rend les dates des nb derniers jours
# dans l'ordre chronologique
# aujourd'hui compris
# nb = 1 : rend hier
def lastdays(nb):
    morning = this_morning()
    days = {}
    for i in range(1, nb+1):
        days[i] = morning - timezone.timedelta(days=nb - i + 1)
    return days


def lastweeks(nb):
    monday_morning = this_monday_morning()
    mondays = {}
    for i in range(1, nb+1):
        mondays[i] = monday_morning \
                    - timezone.timedelta(days=7*(nb - i + 1))
    return mondays


def lastmonths(nb):
    first_month_day = this_first_month_day()
    first_days = {}
    this_year = first_month_day.year
    this_month = first_month_day.month
    for i in range(1, nb+1):
        month = ((this_month - 1 - (nb - i)) % 12) + 1
        year = this_year + (nb - i) // 12
        first_days[i] = timezone.datetime(year=year,
                                          month=month,
                                          day=1,
                                          hour=KFET_WAKES_UP_AT)
    return first_days


def this_first_month_day():
    now = timezone.now()
    first_day = timezone.datetime(year=now.year,
                                  month=now.month,
                                  day=1,
                                  hour=KFET_WAKES_UP_AT)
    return first_day


def this_monday_morning():
    now = timezone.now()
    monday = now - timezone.timedelta(days=now.isoweekday()-1)
    monday_morning = timezone.datetime(year=monday.year,
                                       month=monday.month,
                                       day=monday.day,
                                       hour=KFET_WAKES_UP_AT)
    return monday_morning


def this_morning():
    now = timezone.now()
    morning = timezone.datetime(year=now.year,
                                month=now.month,
                                day=now.day,
                                hour=KFET_WAKES_UP_AT)
    return morning


# Étant donné un queryset d'operations
# rend la somme des article_nb
def tot_ventes(queryset):
    res = queryset.aggregate(Sum('article_nb'))['article_nb__sum']
    return res and res or 0