import uuid
from django.db import models
from django.contrib.auth.models import User
from datetime import datetime, timezone
from billard import utils
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.core.mail import mail_admins
from celery import shared_task
from .tasks import request_process_location_data


class LocationData(models.Model):
    client_id = models.UUIDField(blank=False, null=False, verbose_name="Client-ID")
    desk_no = models.IntegerField(blank=False, null=False, verbose_name="Tischnummer")
    tst = models.DateTimeField(blank=False, null=False, verbose_name="Zeitstempel")
    on_off = models.BooleanField(blank=False, null=False, verbose_name="Ein/Ausgebucht")
    processed = models.BooleanField(default=False, verbose_name="Verarbeitet")
    error_msg = models.TextField(blank=True, null=True, verbose_name="Fehlermeldung")

    def __str__(self):
        return str(self.client_id)

    class Meta:
        verbose_name = "Standortlog"
        verbose_name_plural = "Standortlogs"


class Location(models.Model):
    users = models.ManyToManyField(User, related_name='locations', verbose_name="Benutzer")
    code = models.CharField(max_length=16, unique=True, verbose_name="Code")
    name = models.CharField(max_length=64, unique=True, verbose_name="Name")
    street = models.CharField(max_length=64, blank=True, null=True, verbose_name="Straße")
    plz = models.CharField(max_length=8, blank=True, null=True, verbose_name="Postleitzahl")
    city = models.CharField(max_length=64, blank=True, null=True, verbose_name="Stadt")
    phone = models.CharField(max_length=64, blank=True, null=True, verbose_name="Telefon")
    email = models.EmailField(blank=True, null=True, verbose_name="Email")
    url = models.URLField(blank=True,null=True, verbose_name="URL")

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = "Standort"
        verbose_name_plural = "Standorte"


class Client(models.Model):
    uuid = models.UUIDField(unique=True, default=uuid.uuid4, verbose_name="Identifier")
    location = models.ForeignKey(Location, verbose_name="Standort")

    def __str__(self):
        return '{}, {}'.format(self.location.name, self.uuid)

    class Meta:
        verbose_name = "Client"
        verbose_name_plural = "Clienten"


class Desk(models.Model):
    client = models.ForeignKey(Client, verbose_name='Client', related_name='desks')
    desk_no = models.IntegerField(verbose_name='Tischnummer')
    name = models.CharField(max_length=32, blank=True, null=True, verbose_name='Tischbezeichnung')
    enabled = models.BooleanField(verbose_name='Tisch aktiv')
    prize = models.DecimalField(max_digits=5, decimal_places=2, default=0.0, verbose_name="Normelpreis")
    prize_hh = models.DecimalField(max_digits=5, decimal_places=2, blank=True, null=True,
                                   verbose_name="Preis Happy Hour")

    def accounting_for(self):
        t = Accounting.objects.filter(client=self.client, desk_no=self.desk_no)[:3][::-1]
        if t.__len__() > 0:
            a = t[t.__len__() - 1]
            if a.time_to is None:
                prize = utils.get_prize_for(start=a.time_from, end=datetime.now(timezone.utc), pph=self.prize)
                if prize != a.prize:
                    a.prize = prize
        return t

    def __str__(self):
        return '{}, {}'.format(self.client.uuid, self.name)

    class Meta:
        verbose_name = "Tisch"
        verbose_name_plural = "Tische"


class Accounting(models.Model):
    desk = models.ForeignKey(Desk, verbose_name="Tisch")
    time_from = models.DateTimeField(verbose_name="Beginn")
    time_to = models.DateTimeField(blank=True, null=True, verbose_name="Ende")
    prize = models.DecimalField(max_digits=5, decimal_places=2, blank=True, null=True, verbose_name="Preis")
    billed = models.BooleanField(default=False, verbose_name="Abgerechnet")

    def __str__(self):
        return '{}: {} -> {}, {}, {}'.format(self.desk, self.time_from, self.time_to, self.prize, self.billed)

    class Meta:
        ordering = ['-time_from']
        verbose_name = "Buchhaltungseintrag"
        verbose_name_plural = "Buchhaltungseinträge"


@receiver(post_save, sender=LocationData)
def test(sender, **kwargs):
    request_process_location_data.delay()


@shared_task
def process_location_data():
    data = LocationData.objects.filter(processed=False)
    for ld in data:
        cli = Client.objects.filter(uuid=ld.client_id, desks__desk_no=ld.desk_no)
        if cli.count() < 1:
            ld.processed = True
            ld.error_msg = 'No client object found. Stopp processing! {}, {}'.format(ld.client_id, ld.desk_no)
            ld.save()
            mail_admins(subject=ld.error_msg, message=ld.error_msg)
        else:
            cli = cli[0]
            desk = cli.desks.filter(desk_no=ld.desk_no, enabled=True)
            if desk.count() != 1:
                ld.processed = True
                ld.error_msg = 'No desk object found. Stopp processing! {}, {}'.format(ld.client_id, ld.desk_no)
                ld.save()
                mail_admins(subject=ld.error_msg, message=ld.error_msg)
            desk = desk[0]
            ac = desk.accounting_set.order_by('time_from').reverse()
            if ld.on_off:
                acc = None
                if ac.count() > 0 and ac[0].time_to is None:
                    mail_admins(subject='Accounting passt nicht',
                                message='Vorheriges Accounting nicht abgeschlossen: Desk_id {}, Accounting_id {}'
                                .format(desk.id, ac[0].id))
                    acc = ac[0]
                if acc is None:
                    acc = Accounting(
                        desk=desk,
                        time_from=ld.tst,
                    )
                acc.save()
                ld.delete()
            else:
                acc = ac[0]
                acc.time_to = ld.tst
                acc.prize = utils.get_prize_for(
                    start=acc.time_from,
                    end=ld.tst,
                    pph=desk.prize
                )
                acc.save()
                ld.delete()