"""
Gunicorn Configuration for WebDAV Server
Production-grade WSGI server configuration with aiohttp worker
"""

import os
import multiprocessing

# ============================================================================
# Server Socket
# ============================================================================

bind = f"{os.getenv('HOST', '0.0.0.0')}:{os.getenv('PORT', '8080')}"
backlog = 2048

# ============================================================================
# Worker Processes
# ============================================================================

# Number of worker processes
workers = int(os.getenv('WORKERS', multiprocessing.cpu_count() * 2 + 1))

# Worker class - MUST be aiohttp.GunicornWebWorker for aiohttp
worker_class = 'aiohttp.GunicornWebWorker'

# Worker connections (only for async workers)
worker_connections = int(os.getenv('WORKER_CONNECTIONS', 1024))

# Maximum requests a worker will process before restarting (prevents memory leaks)
max_requests = int(os.getenv('MAX_REQUESTS', 10000))
max_requests_jitter = int(os.getenv('MAX_REQUESTS_JITTER', 1000))

# Worker timeout in seconds
timeout = int(os.getenv('WORKER_TIMEOUT', 60))

# Graceful timeout for workers
graceful_timeout = int(os.getenv('GRACEFUL_TIMEOUT', 30))

# Keep-alive timeout
keepalive = int(os.getenv('KEEPALIVE_TIMEOUT', 30))

# ============================================================================
# Logging
# ============================================================================

# Access log
accesslog = os.getenv('ACCESS_LOG_FILE', './logs/gunicorn_access.log')
access_log_format = '%(h)s %(l)s %(u)s %(t)s "%(r)s" %(s)s %(b)s "%(f)s" "%(a)s" %(D)s'

# Error log
errorlog = os.getenv('ERROR_LOG_FILE', './logs/gunicorn_error.log')

# Log level
loglevel = os.getenv('LOG_LEVEL', 'info').lower()

# Capture output from workers
capture_output = True

# Enable log rotation
logconfig_dict = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'generic': {
            'format': '%(asctime)s [%(process)d] [%(levelname)s] %(message)s',
            'datefmt': '%Y-%m-%d %H:%M:%S',
            'class': 'logging.Formatter'
        },
        'access': {
            'format': '%(message)s',
            'class': 'logging.Formatter'
        }
    },
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
            'formatter': 'generic',
            'stream': 'ext://sys.stdout'
        },
        'error_file': {
            'class': 'logging.handlers.RotatingFileHandler',
            'formatter': 'generic',
            'filename': errorlog,
            'maxBytes': 10485760,  # 10MB
            'backupCount': 5
        },
        'access_file': {
            'class': 'logging.handlers.RotatingFileHandler',
            'formatter': 'access',
            'filename': accesslog,
            'maxBytes': 10485760,  # 10MB
            'backupCount': 5
        }
    },
    'loggers': {
        'gunicorn.error': {
            'handlers': ['console', 'error_file'],
            'level': loglevel.upper(),
            'propagate': False
        },
        'gunicorn.access': {
            'handlers': ['access_file'],
            'level': 'INFO',
            'propagate': False
        }
    },
    'root': {
        'level': loglevel.upper(),
        'handlers': ['console', 'error_file']
    }
}

# ============================================================================
# Process Naming
# ============================================================================

proc_name = 'webdav_server'

# ============================================================================
# Server Mechanics
# ============================================================================

# Daemon mode (run in background)
daemon = os.getenv('DAEMON', 'false').lower() == 'true'

# PID file
pidfile = os.getenv('PID_FILE', './gunicorn.pid')

# User and group to run workers
user = os.getenv('USER', None)
group = os.getenv('GROUP', None)

# Directory to switch to before loading apps
chdir = os.getenv('CHDIR', '.')

# Environment variables to set for workers
raw_env = [
    f"WEBDAV_ENV={os.getenv('WEBDAV_ENV', 'production')}"
]

# ============================================================================
# Server Hooks
# ============================================================================

def on_starting(server):
    """Called just before the master process is initialized."""
    server.log.info("Starting WebDAV Server...")
    
    # Create necessary directories
    os.makedirs('./logs', exist_ok=True)
    os.makedirs('./webdav', exist_ok=True)
    os.makedirs('./backups', exist_ok=True)


def on_reload(server):
    """Called to recycle workers during a reload."""
    server.log.info("Reloading WebDAV Server...")


def when_ready(server):
    """Called just after the server is started."""
    server.log.info(f"WebDAV Server is ready. Listening on: {bind}")
    server.log.info(f"Workers: {workers}")
    server.log.info(f"Worker class: {worker_class}")


def pre_fork(server, worker):
    """Called just before a worker is forked."""
    pass


def post_fork(server, worker):
    """Called just after a worker has been forked."""
    server.log.info(f"Worker spawned (pid: {worker.pid})")


def pre_exec(server):
    """Called just before a new master process is forked."""
    server.log.info("Forked child, re-executing.")


def worker_int(worker):
    """Called when a worker receives the SIGINT or SIGQUIT signal."""
    worker.log.info(f"Worker received INT or QUIT signal (pid: {worker.pid})")


def worker_abort(worker):
    """Called when a worker receives the SIGABRT signal."""
    worker.log.info(f"Worker received SIGABRT signal (pid: {worker.pid})")


def pre_request(worker, req):
    """Called just before a worker processes the request."""
    worker.log.debug(f"{req.method} {req.path}")


def post_request(worker, req, environ, resp):
    """Called after a worker processes the request."""
    pass


def worker_exit(server, worker):
    """Called just after a worker has been exited."""
    server.log.info(f"Worker exited (pid: {worker.pid})")


def on_exit(server):
    """Called just before exiting Gunicorn."""
    server.log.info("Shutting down WebDAV Server...")

# ============================================================================
# SSL Configuration (if needed)
# ============================================================================

# Uncomment and configure for SSL support
# keyfile = '/path/to/key.pem'
# certfile = '/path/to/cert.pem'
# ssl_version = 'TLSv1_2'
# cert_reqs = 0  # ssl.CERT_NONE
# ca_certs = None
# suppress_ragged_eofs = True
# do_handshake_on_connect = False
# ciphers = 'TLSv1'