from django.db import models
from django.contrib.auth import get_user_model
from django.urls import reverse
from django.core.exceptions import ValidationError

from tickets.models.ticket_list import TicketList


class Ticket(models.Model):
    TICKET_TYPES = (
        (1, "ST_REQUEST", [[111, 121, 149, 159], [110, 121, 149, 159], [121, 131, 149, 159], [131, 141, 149], [141, 151, 110], [149, 151, 110], [159], [151]]),
        (2, "SERVICE_REQUEST", [[210, 211, 251], [211, 212, 220, 238, 249], [212, 221, 229, 238, 249], [221, 222, 238, 249], [220, 211, 238, 249], [229, 211, 251], [222, 231, 238, 249], [231, 241, 238, 249], [238, 231, 239, 211, 212, 221, 220, 222, 249], [239, 231, 239, 211, 212, 221, 220, 222, 249], [241, 251], [249, 251], [251]]),
        (3, "ACCESS_REQUEST", [[320, 321, 359], [321], [359]]),
        (4, "NEG_REQUEST", [[420, 421, 459], [421], [459]])
    )

    TICKET_TYPES_CHOICES = tuple((item[0], item[1]) for item in TICKET_TYPES)

    LIFE_CYCLE_DICT = dict((item[0], item[2]) for item in TICKET_TYPES)
    TICKET_TYPES_DICT = dict(TICKET_TYPES_CHOICES)

    title = models.CharField(max_length=128)
    ticket_list = models.ForeignKey(TicketList, on_delete=models.CASCADE)
    ticket_type = models.PositiveSmallIntegerField(choices=TICKET_TYPES_CHOICES)
    status = models.PositiveSmallIntegerField(null=True)
    created_at = models.DateTimeField(auto_now_add=True, editable=False)
    updated_at = models.DateTimeField(auto_now=True)
    due_date = models.DateField()
    created_by = models.ForeignKey(get_user_model(), on_delete=models.SET_NULL, null=True, related_name="created_by", editable=False)
    assigned_to = models.ForeignKey(get_user_model(), on_delete=models.SET_NULL, null=True, blank=True, related_name="assigned_to")
    note = models.TextField(blank=True, null=True)
    priority = models.PositiveSmallIntegerField(default=0)

    def __str__(self):
        return self.title

    def _get_statuses(self) -> list:
        return self.LIFE_CYCLE_DICT.get(self.ticket_type)

    def get_available_statuses(self) -> list:
        for status_scenario in self._get_statuses():
            if status_scenario[0] == int(self.status):
                return status_scenario[1:] if len(status_scenario) > 1 else None

    def set_first_status(self):
        self.status = self._get_statuses()[0][0]

    def save(self, *args, **kwargs):
        if not self.status:
            self.set_first_status()
        else:
            unique_statuses = set()
            for status_group in self._get_statuses():
                for status in status_group:
                    unique_statuses.add(status)

            if self.status not in unique_statuses:
                self.set_first_status()
        
        super(Ticket, self).save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse("tickets:ticket_detail", kwargs={"ticket_id": self.id})

    class Meta:
        ordering = ["-priority", "created_at"]