import uuid
from django.conf import settings
from django.db import models
from django.db.models import Q
class Segment(models.Model):
    name=models.CharField(max_length=100,unique=True)
    cidr=models.CharField(max_length=100,blank=True)
    def __str__(self): return self.name
class Server(models.Model):
    id=models.UUIDField(primary_key=True,default=uuid.uuid4,editable=False)
    name=models.CharField(max_length=150,unique=True)
    segment=models.ForeignKey(Segment,on_delete=models.PROTECT)
    address=models.CharField(max_length=255,blank=True)
    enabled=models.BooleanField(default=True)
    maintenance=models.BooleanField(default=False)
    last_seen=models.DateTimeField(null=True,blank=True)
    latest_sample_at=models.DateTimeField(null=True,blank=True)
    latest=models.JSONField(default=dict,blank=True)
    created_at=models.DateTimeField(auto_now_add=True)
    def __str__(self): return self.name
class AgentCredential(models.Model):
    server=models.ForeignKey(Server,on_delete=models.CASCADE)
    digest=models.CharField(max_length=64,unique=True)
    label=models.CharField(max_length=100,default='agent')
    active=models.BooleanField(default=True)
    created_at=models.DateTimeField(auto_now_add=True)
class AccessToken(models.Model):
    user=models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE)
    digest=models.CharField(max_length=64,unique=True)
    expires_at=models.DateTimeField(db_index=True)
class Event(models.Model):
    id=models.UUIDField(primary_key=True)
    server=models.ForeignKey(Server,on_delete=models.CASCADE)
    kind=models.CharField(max_length=50,db_index=True)
    occurred_at=models.DateTimeField(db_index=True)
    received_at=models.DateTimeField(auto_now_add=True,db_index=True)
    payload=models.JSONField(default=dict)
    class Meta:
        indexes=[models.Index(fields=['server','occurred_at']),models.Index(fields=['server','kind','occurred_at'])]
class Metric(models.Model):
    event=models.OneToOneField(Event,on_delete=models.CASCADE,primary_key=True)
    server=models.ForeignKey(Server,on_delete=models.CASCADE)
    at=models.DateTimeField(db_index=True)
    cpu=models.FloatField()
    ram=models.FloatField()
    disk=models.FloatField()
    class Meta:
        indexes=[models.Index(fields=['server','at'])]
class Worker(models.Model):
    server=models.ForeignKey(Server,on_delete=models.CASCADE)
    hostname=models.CharField(max_length=255)
    last_seen=models.DateTimeField()
    online=models.BooleanField(default=True)
    active=models.IntegerField(default=0)
    processed=models.BigIntegerField(default=0)
    class Meta:
        constraints=[models.UniqueConstraint(fields=['server','hostname'],name='unique_worker_per_collector')]
class Task(models.Model):
    server=models.ForeignKey(Server,on_delete=models.CASCADE)
    task_id=models.CharField(max_length=200)
    name=models.CharField(max_length=255,blank=True)
    worker=models.CharField(max_length=255,blank=True)
    state=models.CharField(max_length=30)
    first_at=models.DateTimeField()
    last_at=models.DateTimeField(db_index=True)
    runtime=models.FloatField(null=True,blank=True)
    retries=models.IntegerField(default=0)
    class Meta:
        constraints=[models.UniqueConstraint(fields=['server','task_id'],name='unique_task_per_collector')]
        indexes=[models.Index(fields=['server','last_at'])]
class Alarm(models.Model):
    server=models.ForeignKey(Server,on_delete=models.CASCADE)
    code=models.CharField(max_length=80)
    severity=models.CharField(max_length=20,default='warning')
    message=models.CharField(max_length=400)
    opened_at=models.DateTimeField(auto_now_add=True)
    resolved_at=models.DateTimeField(null=True,blank=True)
    acknowledged_at=models.DateTimeField(null=True,blank=True)
    acknowledged_by=models.ForeignKey(settings.AUTH_USER_MODEL,null=True,blank=True,on_delete=models.SET_NULL)
    class Meta:
        constraints=[models.UniqueConstraint(fields=['server','code'],condition=Q(resolved_at__isnull=True),name='one_open_alarm')]
class Notification(models.Model):
    alarm=models.OneToOneField(Alarm,on_delete=models.CASCADE)
    sent_at=models.DateTimeField(null=True,blank=True)
    attempts=models.IntegerField(default=0)
    next_attempt=models.DateTimeField()
    last_error=models.CharField(max_length=100,blank=True)
class Configuration(models.Model):
    id=models.PositiveSmallIntegerField(primary_key=True,default=1,editable=False)
    retention_days=models.PositiveIntegerField(default=90)
    heartbeat_timeout=models.PositiveIntegerField(default=60)
    cpu_warning=models.PositiveIntegerField(default=85)
    ram_warning=models.PositiveIntegerField(default=90)
    disk_warning=models.PositiveIntegerField(default=90)
    updated_at=models.DateTimeField(auto_now=True)
class Audit(models.Model):
    at=models.DateTimeField(auto_now_add=True)
    actor=models.CharField(max_length=150)
    action=models.CharField(max_length=200)
    details=models.JSONField(default=dict)