import logging

import requests
from celery import shared_task
from django.utils import timezone

from labs.models import LabSSHServer

logger = logging.getLogger(__name__)


@shared_task
def ssh_servers_health_check():
    ssh_servers = LabSSHServer.objects.all()
    for ssh_server in ssh_servers:
        try:
            response = requests.get(
                f"https://{ssh_server.domain}/health",
                timeout=5,
            )
            if response.status_code == 200:
                # increment success streak; require 2 consecutive successes to recover
                if ssh_server.status == LabSSHServer.Status.UNHEALTHY:
                    ssh_server.healthy_success_streak = (
                        ssh_server.healthy_success_streak or 0
                    ) + 1
                    if ssh_server.healthy_success_streak >= 2:
                        ssh_server.status = LabSSHServer.Status.HEALTHY
                        ssh_server.healthy_success_streak = 0
                        ssh_server.save(
                            update_fields=["status", "healthy_success_streak"]
                        )
                    else:
                        ssh_server.save(update_fields=["healthy_success_streak"])
                else:
                    if ssh_server.healthy_success_streak != 0:
                        ssh_server.healthy_success_streak = 0
                        ssh_server.save(update_fields=["healthy_success_streak"])
            else:
                raise Exception(
                    f"SSH server is unhealthy, ssh_server_id: {ssh_server.id}, "
                    f"status code: {response.status_code}, response: {response.text[:200]}"
                )
        except Exception as e:
            logger.error(
                f"Unexpected error during health check, ssh_server_id: {ssh_server.id}, error: {e}"
            )
            update_fields = ["status", "healthy_success_streak"]
            if ssh_server.status != LabSSHServer.Status.UNHEALTHY:
                ssh_server.last_unhealthy_at = timezone.now()
                update_fields.append("last_unhealthy_at")
            ssh_server.status = LabSSHServer.Status.UNHEALTHY
            ssh_server.healthy_success_streak = 0
            ssh_server.save(update_fields=update_fields)