from django.conf import settings
from django.db import models

from apps.tickets.models import Ticket, TicketCategory


class Solution(models.Model):
    title = models.CharField(max_length=200)
    problem_signature = models.TextField()
    related_system = models.CharField(max_length=120, blank=True)
    environment_scope = models.CharField(max_length=120, blank=True)
    category = models.ForeignKey(TicketCategory, null=True, blank=True, on_delete=models.SET_NULL)
    root_cause = models.TextField()
    solution = models.TextField()
    risk_note = models.TextField(blank=True)
    status = models.CharField(max_length=40, default="draft")
    allow_auto_resolve = models.BooleanField(default=False)
    requires_human_action = models.BooleanField(default=False)
    requires_external_confirmation = models.BooleanField(default=False)
    requires_production_change = models.BooleanField(default=False)
    usage_count = models.PositiveIntegerField(default=0)
    created_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ["-updated_at"]

    def __str__(self) -> str:
        return self.title


class TicketResolution(models.Model):
    ticket = models.OneToOneField(Ticket, on_delete=models.CASCADE, related_name="resolution")
    resolution_type = models.CharField(max_length=80, default="resolved")
    source = models.CharField(max_length=24, default="human")
    root_cause = models.TextField(blank=True)
    solution_text = models.TextField()
    linked_solution = models.ForeignKey(Solution, null=True, blank=True, on_delete=models.SET_NULL)
    agent_run_id = models.BigIntegerField(null=True, blank=True)
    confirmed_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)


class TicketSolutionLink(models.Model):
    ticket = models.ForeignKey(Ticket, on_delete=models.CASCADE, related_name="solution_links")
    solution = models.ForeignKey(Solution, on_delete=models.CASCADE, related_name="ticket_links")
    link_type = models.CharField(max_length=40, default="referenced")
    agent_run_id = models.BigIntegerField(null=True, blank=True)
    created_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        unique_together = [("ticket", "solution", "link_type")]