from django.db import models
from django.conf import settings
from django.utils import timezone
from django.utils.translation import gettext_lazy as _

from datetime import timedelta


class OnlineExamRegistrate(models.Model):

    PAYMENT_CODE = 0
    PAYMENT_ONLINE = 1
    PAYMENT_CHOICES = (
        (PAYMENT_CODE, _('promotion code')),
        (PAYMENT_ONLINE, _('online payment'))
    )

    FLAG_PCTA = 'PCTA'
    FLAG_PCTP = 'PCTP'
    FLAG_CHOICES = (
        (FLAG_PCTA, 'PCTA'),
        (FLAG_PCTP, 'PCTP')
    )

    EXAM_MODIFY_MAX_TIMES = 2

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL, on_delete=models.DO_NOTHING)
    online_exam = models.ForeignKey(
        'university.OnlineExam', on_delete=models.CASCADE)
    flag = models.CharField(
        max_length=32, default=FLAG_PCTA, choices=FLAG_CHOICES)
    name = models.CharField(max_length=64)
    chinese_id = models.CharField(max_length=64)
    phone = models.CharField(max_length=64)
    email = models.EmailField()
    company = models.CharField(max_length=64)
    city = models.CharField(max_length=64)
    tug_role = models.CharField(max_length=64)
    payment_method = models.SmallIntegerField(choices=PAYMENT_CHOICES, default=PAYMENT_CODE)
    promotion_code = models.ForeignKey(
        'university.OnlineExamPromotionCode', on_delete=models.DO_NOTHING, null=True, blank=True)
    online_payment_success = models.BooleanField(default=False)
    need_receipt = models.BooleanField(default=False)
    receipt_header = models.CharField(max_length=128, blank=True, null=True)
    receipt_tin = models.CharField(max_length=255, blank=True, null=True)
    obtained_dba_certs = models.CharField(max_length=255, blank=True, null=True)
    exam_modified_times = models.IntegerField(default=0)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = 'online_exam_registrate'
        unique_together = ('user', 'online_exam')

    @property
    def exam_modification_remaining(self):
        return self.EXAM_MODIFY_MAX_TIMES - self.exam_modified_times

    @property
    def can_update_exam(self):
        return self.online_exam.start_at - timedelta(days=3) > timezone.now()

    @property
    def can_update_info_except_exam(self):
        return self.online_exam.start_at > timezone.now()