# -*- coding: utf-8 -*-

from __future__ import unicode_literals
from django.db import models
from django.conf import settings
from .fields import MACAddressField


class ItemType(models.Model):
    name = models.CharField(max_length=100, verbose_name='nom')

    def __unicode__(self):
        return self.name

    class Meta:
        verbose_name = 'type d’objet'
        verbose_name_plural = 'types d’objet'


class Item(models.Model):
    type = models.ForeignKey(ItemType, verbose_name='type de matériel',
                             related_name='items')
    designation = models.CharField(max_length=100, verbose_name='désignation')
    mac_address = MACAddressField(verbose_name='addresse MAC', blank=True,
                                  null=True)
    buy_date = models.DateTimeField(verbose_name='date d’achat')
    user_in_charge = models.ForeignKey(settings.AUTH_USER_MODEL,
                                       verbose_name='membre responsable',
                                       related_name='items')
    comment = models.TextField(verbose_name='commentaire', blank=True,
                               null=True)

    def __unicode__(self):
        return self.designation

    def get_current_loan(self):
        """
        Returns the current Loan for this Item, if exists, or None.
        """
        try:
            return self.loans.get(loan_date_end__isnull=True)
        except Loan.DoesNotExist:
            return None

    def is_available(self):
        """
        Returns the status of the Item. If a Loan without an end date exists,
        returns False (else True).
        """
        if self.loans.filter(loan_date_end__isnull=True).count():
            return False
        return True

    class Meta:
        verbose_name = 'objet'


class Loan(models.Model):
    item = models.ForeignKey(Item, verbose_name='objet', related_name='loans')
    user = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name='membre',
                             related_name='loans')
    loan_date = models.DateTimeField(verbose_name='date de prêt')
    loan_date_end = models.DateTimeField(verbose_name='date de fin de prêt',
                                         null=True, blank=True)
    location = models.CharField(max_length=100, verbose_name='emplacement',
                                null=True, blank=True)

    def __unicode__(self):
        return 'prêt de {item} à {user}'.format(item=self.item,
                                                user=self.user)

    class Meta:
        verbose_name = 'prêt d’objet'
        verbose_name_plural = 'prêts d’objets'