"""
Signal handlers for automation_orchestration app
"""
from django.db.models.signals import post_save, pre_save
from django.dispatch import receiver
from django.utils import timezone
from .models import (
    RunbookExecution,
    AutoRemediationExecution,
    MaintenanceWindow,
)


@receiver(post_save, sender=RunbookExecution)
def update_runbook_statistics(sender, instance, created, **kwargs):
    """Update runbook statistics when execution is completed"""
    if instance.status in ['COMPLETED', 'FAILED', 'CANCELLED', 'TIMEOUT']:
        runbook = instance.runbook
        runbook.execution_count += 1
        
        if instance.status == 'COMPLETED':
            # Update success rate
            total_executions = runbook.execution_count
            successful_executions = RunbookExecution.objects.filter(
                runbook=runbook,
                status='COMPLETED'
            ).count()
            runbook.success_rate = successful_executions / total_executions if total_executions > 0 else 0.0
        
        runbook.last_executed_at = instance.started_at
        runbook.save(update_fields=['execution_count', 'success_rate', 'last_executed_at'])


@receiver(post_save, sender=AutoRemediationExecution)
def update_auto_remediation_statistics(sender, instance, created, **kwargs):
    """Update auto-remediation statistics when execution is completed"""
    if instance.status in ['COMPLETED', 'FAILED', 'CANCELLED', 'TIMEOUT']:
        remediation = instance.auto_remediation
        remediation.execution_count += 1
        
        if instance.status == 'COMPLETED':
            remediation.success_count += 1
        
        remediation.last_executed_at = instance.triggered_at
        remediation.save(update_fields=['execution_count', 'success_count', 'last_executed_at'])


@receiver(pre_save, sender=MaintenanceWindow)
def validate_maintenance_window(sender, instance, **kwargs):
    """Validate maintenance window before saving"""
    if instance.start_time and instance.end_time:
        if instance.start_time >= instance.end_time:
            raise ValueError("Start time must be before end time")
    
    # Auto-update status based on current time
    now = timezone.now()
    if instance.start_time and instance.end_time:
        if instance.start_time <= now <= instance.end_time:
            if instance.status == 'SCHEDULED':
                instance.status = 'ACTIVE'
        elif instance.end_time < now:
            if instance.status in ['SCHEDULED', 'ACTIVE']:
                instance.status = 'COMPLETED'