import uuid

from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils import timezone


class User(AbstractUser):
    class Track(models.TextChoices):
        BEGINNER = "beginner", "入门"
        STANDARD = "standard", "标准"
        ADVANCED = "advanced", "进阶"
        OPEN = "open", "Open"

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    nickname = models.CharField(max_length=40)
    avatar_url = models.URLField(blank=True)
    bio = models.CharField(max_length=200, blank=True)
    track = models.CharField(max_length=16, choices=Track.choices, default=Track.STANDARD)
    rating = models.PositiveIntegerField(default=1000)

    def __str__(self):
        return self.nickname or self.username


class InviteCode(models.Model):
    code = models.CharField(max_length=32, unique=True)
    group = models.CharField(max_length=80, blank=True)
    max_uses = models.PositiveIntegerField(default=1)
    used_count = models.PositiveIntegerField(default=0)
    expires_at = models.DateTimeField(null=True, blank=True)
    is_active = models.BooleanField(default=True)
    created_by = models.ForeignKey(
        User, null=True, blank=True, on_delete=models.SET_NULL, related_name="invite_codes"
    )
    created_at = models.DateTimeField(auto_now_add=True)

    @property
    def is_available(self):
        return (
            self.is_active
            and self.used_count < self.max_uses
            and (self.expires_at is None or self.expires_at > timezone.now())
        )

    def __str__(self):
        return self.code


class InviteCodeUsage(models.Model):
    invite_code = models.ForeignKey(InviteCode, on_delete=models.PROTECT, related_name="usages")
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name="invite_usage")
    used_at = models.DateTimeField(auto_now_add=True)
    ip_address = models.GenericIPAddressField(null=True, blank=True)


class UserSession(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="login_sessions")
    session_key = models.CharField(max_length=40, unique=True)
    user_agent = models.CharField(max_length=300, blank=True)
    ip_address = models.GenericIPAddressField(null=True, blank=True)
    last_seen_at = models.DateTimeField(auto_now=True)
    revoked_at = models.DateTimeField(null=True, blank=True)


class VisitorMigration(models.Model):
    class Status(models.TextChoices):
        PENDING = "pending", "待确认"
        APPLIED = "applied", "已迁移"

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name="visitor_migration")
    payload = models.JSONField(default=dict)
    summary = models.JSONField(default=dict)
    status = models.CharField(max_length=16, choices=Status.choices, default=Status.PENDING)
    created_at = models.DateTimeField(auto_now_add=True)
    applied_at = models.DateTimeField(null=True, blank=True)


class AuditLog(models.Model):
    actor = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
    action = models.CharField(max_length=80)
    target_type = models.CharField(max_length=80)
    target_id = models.CharField(max_length=80, blank=True)
    reason = models.CharField(max_length=300, blank=True)
    metadata = models.JSONField(default=dict, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ["-created_at"]