"""
Базовые views для конфигурации.
"""
import time
import mimetypes
from pathlib import Path

from django.http import JsonResponse, FileResponse, Http404
from django.db import connection
from django.core.cache import cache
from django.conf import settings
import redis
import logging

logger = logging.getLogger(__name__)


def serve_media(request, path):
    """
    Безопасная раздача медиа-файлов (работает при DEBUG=False при обращении к Django на порту 8123).
    Проверяет path на path traversal; отдаёт файл из MEDIA_ROOT.
    """
    media_root = Path(settings.MEDIA_ROOT).resolve()
    # Запрет path traversal: путь должен оставаться внутри MEDIA_ROOT
    file_path = (media_root / path).resolve()
    if not str(file_path).startswith(str(media_root)) or not file_path.exists():
        raise Http404("Media file not found")
    if file_path.is_dir():
        raise Http404("Media file not found")
    content_type, _ = mimetypes.guess_type(str(file_path))
    response = FileResponse(
        open(file_path, "rb"),
        as_attachment=False,
        filename=file_path.name,
        content_type=content_type or "application/octet-stream",
    )
    response["Cache-Control"] = "public, max-age=604800"  # 7 дней
    return response


def health_check(request):
    """
    Health check endpoint для мониторинга.
    Проверяет доступность БД, Redis, Celery и WebSocket.
    """
    start_time = time.time()
    health_status = {
        'status': 'healthy',
        'timestamp': time.time(),
        'checks': {}
    }
    
    # Проверка базы данных
    try:
        db_start = time.time()
        with connection.cursor() as cursor:
            cursor.execute('SELECT 1')
        db_time = (time.time() - db_start) * 1000  # в миллисекундах
        health_status['checks']['database'] = {
            'status': 'healthy',
            'message': 'Database connection successful',
            'response_time_ms': round(db_time, 2)
        }
    except Exception as e:
        health_status['status'] = 'unhealthy'
        health_status['checks']['database'] = {
            'status': 'unhealthy',
            'message': f'Database error: {str(e)}',
            'response_time_ms': None
        }
        logger.error(f'Database health check failed: {e}', exc_info=True)
    
    # Проверка Redis
    try:
        redis_start = time.time()
        cache.set('health_check', 'ok', 10)
        cache_value = cache.get('health_check')
        redis_time = (time.time() - redis_start) * 1000
        if cache_value == 'ok':
            health_status['checks']['redis'] = {
                'status': 'healthy',
                'message': 'Redis connection successful',
                'response_time_ms': round(redis_time, 2)
            }
        else:
            health_status['status'] = 'unhealthy'
            health_status['checks']['redis'] = {
                'status': 'unhealthy',
                'message': 'Redis cache verification failed',
                'response_time_ms': round(redis_time, 2)
            }
    except Exception as e:
        health_status['status'] = 'unhealthy'
        health_status['checks']['redis'] = {
            'status': 'unhealthy',
            'message': f'Redis error: {str(e)}',
            'response_time_ms': None
        }
        logger.error(f'Redis health check failed: {e}', exc_info=True)
    
    # Проверка Celery (через Redis)
    try:
        celery_start = time.time()
        from celery import current_app
        inspect = current_app.control.inspect()
        active_workers = inspect.active()
        celery_time = (time.time() - celery_start) * 1000
        
        if active_workers is not None:
            worker_count = len(active_workers)
            health_status['checks']['celery'] = {
                'status': 'healthy',
                'message': f'Celery is running with {worker_count} active worker(s)',
                'worker_count': worker_count,
                'response_time_ms': round(celery_time, 2)
            }
        else:
            health_status['status'] = 'unhealthy'
            health_status['checks']['celery'] = {
                'status': 'unhealthy',
                'message': 'No active Celery workers found',
                'response_time_ms': round(celery_time, 2)
            }
    except Exception as e:
        # Celery может быть недоступен, но это не критично для базового health check
        health_status['checks']['celery'] = {
            'status': 'warning',
            'message': f'Celery check failed: {str(e)}',
            'response_time_ms': None
        }
        logger.warning(f'Celery health check failed: {e}')
    
    # Проверка WebSocket (Channels)
    try:
        ws_start = time.time()
        from channels.layers import get_channel_layer
        channel_layer = get_channel_layer()
        if channel_layer:
            # Простая проверка доступности channel layer
            ws_time = (time.time() - ws_start) * 1000
            health_status['checks']['websocket'] = {
                'status': 'healthy',
                'message': 'WebSocket channel layer is available',
                'response_time_ms': round(ws_time, 2)
            }
        else:
            health_status['checks']['websocket'] = {
                'status': 'warning',
                'message': 'WebSocket channel layer not configured',
                'response_time_ms': None
            }
    except Exception as e:
        health_status['checks']['websocket'] = {
            'status': 'warning',
            'message': f'WebSocket check failed: {str(e)}',
            'response_time_ms': None
        }
        logger.warning(f'WebSocket health check failed: {e}')
    
    # Общее время выполнения
    total_time = (time.time() - start_time) * 1000
    health_status['total_response_time_ms'] = round(total_time, 2)
    
    # Добавляем информацию о версии и окружении
    health_status['version'] = getattr(settings, 'VERSION', '1.0.0')
    health_status['environment'] = 'production' if not settings.DEBUG else 'development'
    
    # Возвращаем 200 если все критичные сервисы здоровы, 503 если есть проблемы
    critical_checks = ['database', 'redis']
    critical_healthy = all(
        health_status['checks'].get(check, {}).get('status') == 'healthy'
        for check in critical_checks
    )
    
    status_code = 200 if critical_healthy else 503
    
    return JsonResponse(health_status, status=status_code)