from django.db import models
from django.core.exceptions import ValidationError
from django.utils.translation import ugettext_lazy as _
from django.contrib.auth.models import Group
from event.models import Activity, EventSpecificMixin
from django.db.models import Q

from .fields import IdField

from datetime import date


class EquipmentCategory(models.Model):
    name = models.CharField(
                _("nom"),
                max_length=200,
                )
    parent = models.ForeignKey(
                'self',
                blank=True,
                null=True,
                default=None,
                on_delete=models.SET_NULL,
                related_name="children",
                help_text=_("merci de ne pas faire de référence cyclique"),
                verbose_name=_("parent"),
                )

    def has_parent(self, cat):
        current = self
        for k in range(100):
            if current is None:
                return False
            if current == cat:
                return True
            current = current.parent

    def full_name(self):
        current = self
        res = ""
        for k in range(100):
            res = "/{current}{old}".format(
                        current=current.name,
                        old=res)
            if current.parent is None:
                break
            current = current.parent
        return res

    full_name.short_description = _("Chemin complet")
    full_name_p = property(full_name)

    class Meta:
        verbose_name = _("catégories")
        verbose_name_plural = _("catégories")

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if self.pk:
            done = False
            current = self
            while not done:
                if current.parent == self:
                    self.parent = None
                    done = True
                elif current.parent is None:
                    done = True
                current = current.parent
        return super().save(*args, **kwargs)


class EquipmentQuerySet(models.QuerySet):
    def in_category(self, cat):
        filtre = Q(id__lt=0)
        childs_id = [c.id for c in EquipmentCategory.objects.all()
                     if c.has_parent(cat)]
        for pk in childs_id:
            filtre |= Q(category__id=pk)
        return self.filter(filtre)


class Equipment(EventSpecificMixin, models.Model):
    name = models.CharField(
                _("nom du matériel"),
                max_length=200,
            )
    stock = models.PositiveSmallIntegerField(_("quantité totale"))
    description = models.TextField(
                    _("description"),
                    blank=True,
                    )
    activities = models.ManyToManyField(
                Activity,
                related_name="equipment",
                through="EquipmentAttribution",
            )
    owner = models.ForeignKey(
            Group,
            verbose_name=_("propriétaire"),
            blank=True,
            null=True,
            on_delete=models.SET_NULL,
            )
    category = models.ForeignKey(
            EquipmentCategory,
            verbose_name=_("catégorie"),
            on_delete=models.PROTECT,
            )

    added_at = models.DateTimeField(
                _("ajouté le"),
                auto_now_add=True,
                )
    modified_at = models.DateTimeField(
                _("dernière modification"),
                auto_now=True,
                )

    objects = EquipmentQuerySet.as_manager()

    def is_in_category(self, cat):
        current = self.category
        for k in range(100):
            if current is None:
                return False
            if current == cat:
                return True
            current = current.parent

    def ids_aviable(self):
        if self.stock is None:
            return []
        res = list(map(lambda x: x+1, range(self.stock)))
        for lost in self.losts.all():
            res = [x
                   for x in res
                   if x not in lost.ids]
        # TODO cassé
        # TODO utilisés
        return res

    def ids_lost(self):
        res = []
        for lost in self.losts.all():
            res = res + [x
                         for x in lost.ids
                         if x not in res]
        return res

    def stock_aviable(self):
        aviable = self.ids_aviable()
        return len(aviable)

    def stock_lost(self):
        return len(self.ids_lost())

    def full_category(self):
        return self.category.full_name()

    full_category.short_description = _("Chemin complet")
    ids_aviable.short_description = _("disponibles")
    ids_lost.short_description = _("perdus")
    stock_aviable.short_description = _("quantité disponible")
    stock_lost.short_description = _("quantité perdue")

    full_category_p = property(full_category)
    ids_aviable_p = property(ids_aviable)
    ids_lost_p = property(ids_lost)
    stock_aviable_p = property(stock_aviable)
    stock_lost_p = property(stock_lost)

    class Meta:
        verbose_name = _("matériel")
        verbose_name_plural = _("matériels")

    def __str__(self):
        return self.name


class EquipmentAttribute(models.Model):
    name = models.CharField(
                _("nom"),
                max_length=200,
                unique=True,
                )

    class Meta:
        verbose_name = _("attribut")
        verbose_name_plural = _("attributs")

    def __str__(self):
        return self.name


class EquipmentAttributeValue(models.Model):
    equipment = models.ForeignKey(
                Equipment,
                on_delete=models.CASCADE,
                related_name="attributes",
                verbose_name=_("matériel"),
                help_text=_("Matériel concerné par le defaut"),
            )
    attribute = models.ForeignKey(
                    EquipmentAttribute,
                    verbose_name=_("attribut"),
                    on_delete=models.CASCADE,
                    )
    value = models.CharField(
                    _("valeur"),
                    max_length=200,
                    )

    class Meta:
        verbose_name = _("attribut de matériel")
        verbose_name_plural = _("attributs de matériel")

    def __str__(self):
        return "{attr}={value}".format(attr=self.attribute.name,
                                       value=self.value)


class EquipmentAttribution(models.Model):
    equipment = models.ForeignKey(
                Equipment,
                verbose_name=_("matériel"),
                on_delete=models.CASCADE,
                )
    activity = models.ForeignKey(
                Activity,
                on_delete=models.CASCADE,
                )
    amount = models.BigIntegerField(_("quantité attribuée"))
    remarks = models.TextField(
                _("remarques concernant l'attribution"),
                blank=True,
                )

    class Meta:
        verbose_name = _("attribution de matériel")
        verbose_name_plural = _("attributions de matériel")

    def __str__(self):
        return "%s (%d) -> %s" % (self.equipment.name,
                                  self.amount,
                                  self.activity.get_herited('title'))

    def save(self, *args, **kwargs):
        if (self.equipment.event
                and self.equipment.event != self.activity.event):
            raise ValidationError

        super(EquipmentAttribution, self).save(*args, **kwargs)


class EquipmentDefault(models.Model):
    remark = models.TextField(_("remarque sur le défaut"))
    equipment = models.ForeignKey(
                Equipment,
                verbose_name=_("matériel"),
                on_delete=models.CASCADE,
                related_name="remarks",
                help_text=_("Matériel concerné par le defaut"),
            )
    ids = IdField()
    is_unusable = models.BooleanField(_("inutilisable"))
    send_repare = models.BooleanField(_("à envoyer réparareur"))

    class Meta:
        verbose_name = _("defaut matériel")
        verbose_name_plural = _("défauts sur le matériel")

    def __str__(self):
        return "%s : %s" % (self.equipment.name,
                            self.remark)


class EquipmentLost(models.Model):
    lost_at = models.DateField(
            _("perdu le"),
            default=date.today,
            )
    equipment = models.ForeignKey(
                Equipment,
                verbose_name=_("matériel"),
                on_delete=models.CASCADE,
                related_name="losts",
                help_text=_("Matériel concerné par la perte"),
            )
    ids = IdField()


class EquipmentRevision(models.Model):
    date = models.DateField(
            _("date"),
            default=date.today,
            )
    equipment = models.ForeignKey(
                Equipment,
                verbose_name=_("matériel"),
                on_delete=models.CASCADE,
                related_name="revisions",
                help_text=_("Matériel concerné par les révisions"),
            )
    remark = models.TextField(_("remarque sur la révision"))
    ids = IdField()

    class Meta:
        verbose_name = _("révision de matériel")
        verbose_name_plural = _("révisions de matériel")

    def __str__(self):
        return "%s : %s" % (self.equipment.name,
                            self.remark)