import os
import sys
import pathlib
import signal
import asyncio
import atexit

# Add project root to Python path to import shared utils
_project_root = pathlib.Path(__file__).parent.parent
if str(_project_root) not in sys.path:
    sys.path.insert(0, str(_project_root))

# 1) Load env and init traceroot BEFORE importing modules that get a logger
from utils import traceroot_wrapper as traceroot
from app import api

# Only initialize traceroot if enabled
if traceroot.is_enabled():
    from traceroot.integrations.fastapi import connect_fastapi
    connect_fastapi(api)

# 2) Now safe to import modules that use traceroot.get_logger() at import-time
from app.component.environment import env
from app.router import register_routers


os.environ["PYTHONIOENCODING"] = "utf-8"

app_logger = traceroot.get_logger("main")

# Log application startup
app_logger.info("Starting Eigent Multi-Agent System API")
app_logger.info(f"Python encoding: {os.environ.get('PYTHONIOENCODING')}")
app_logger.info(f"Environment: {os.environ.get('ENVIRONMENT', 'development')}")

prefix = env("url_prefix", "")
app_logger.info(f"Loading routers with prefix: '{prefix}'")
register_routers(api, prefix)
app_logger.info("All routers loaded successfully")

# Check if debug mode is enabled via environment variable
if os.environ.get('ENABLE_PYTHON_DEBUG') == 'true':
    try:
        import debugpy
        DEBUG_PORT = int(os.environ.get('DEBUG_PORT', '5678'))
        app_logger.info(f"Debug mode enabled - Starting debugpy server on port {DEBUG_PORT}")
        debugpy.listen(("localhost", DEBUG_PORT))
        app_logger.info(f"Debugger ready for attachment on localhost:{DEBUG_PORT}")
        #📝 In VS Code: Run 'Debug Python Backend (Attach)' configuration
        # Don't wait for client automatically - let it attach when ready
    except ImportError:
        app_logger.warning("debugpy not available, install with: uv add debugpy")
    except Exception as e:
        app_logger.error(f"Failed to start debugpy: {e}")


dir = pathlib.Path(__file__).parent / "runtime"
dir.mkdir(parents=True, exist_ok=True)


# Write PID file asynchronously
async def write_pid_file():
    r"""Write PID file asynchronously"""
    import aiofiles

    async with aiofiles.open(dir / "run.pid", "w") as f:
        await f.write(str(os.getpid()))
    app_logger.info(f"PID file written: {os.getpid()}")


# Create task to write PID
pid_task = asyncio.create_task(write_pid_file())
app_logger.info("PID write task created")

# Graceful shutdown handler
shutdown_event = asyncio.Event()


async def cleanup_resources():
    r"""Cleanup all resources on shutdown"""
    app_logger.info("Starting graceful shutdown process")

    from app.service.task import task_locks, _cleanup_task

    if _cleanup_task and not _cleanup_task.done():
        _cleanup_task.cancel()
        try:
            await _cleanup_task
        except asyncio.CancelledError:
            pass

    # Cleanup all task locks
    for task_id in list(task_locks.keys()):
        try:
            task_lock = task_locks[task_id]
            await task_lock.cleanup()
        except Exception as e:
            app_logger.error(f"Error cleaning up task {task_id}: {e}")

    # Remove PID file
    pid_file = dir / "run.pid"
    if pid_file.exists():
        pid_file.unlink()

    app_logger.info("All resources cleaned up successfully")


def signal_handler(signum, frame):
    r"""Handle shutdown signals"""
    app_logger.warning(f"Received shutdown signal: {signum}")
    asyncio.create_task(cleanup_resources())
    shutdown_event.set()


signal.signal(signal.SIGTERM, signal_handler)
signal.signal(signal.SIGINT, signal_handler)

# Register cleanup on exit with safe synchronous wrapper
def sync_cleanup():
    """Synchronous cleanup for atexit - handles PID file removal"""
    try:
        # Only perform synchronous cleanup tasks
        pid_file = dir / "run.pid"
        if pid_file.exists():
            pid_file.unlink()
            app_logger.info("PID file removed during shutdown")
    except Exception as e:
        app_logger.error(f"Error during atexit cleanup: {e}")

atexit.register(sync_cleanup)

# Log successful initialization
app_logger.info("Application initialization completed successfully")