"""SonicForge DAW — Desktop engine launcher (PyInstaller entry point).

Chay FastAPI backend duoi dang tien trinh nen (sidecar) cho ban cai Standalone
Windows (Tauri v2 shell). Tu chon port 8000-8010 (fallback neu bi chiem), tu
thoat khi tien trinh cha (Tauri) ket thuc — Graceful Shutdown.
"""
import logging
import os
import socket
import sys
import threading
import time

PORT_RANGE = (8000, 8010)
APP_DATA_DIR_NAME = "SonicForgeDAW"


def _pick_port():
    for port in range(PORT_RANGE[0], PORT_RANGE[1] + 1):
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
            try:
                s.bind(("127.0.0.1", port))
                return port
            except OSError:
                continue
    return PORT_RANGE[0]


def _parent_alive(pid):
    try:
        os.kill(pid, 0)
        return True
    except OSError:
        return False


def main():
    os.environ.setdefault("SF_DESKTOP", "1")
    port = _pick_port()
    os.environ["SF_PORT"] = str(port)

    # Log ra file — khi dong goi console=False, stdout khong nhin thay duoc.
    try:
        log_dir = os.path.join(
            os.environ.get("APPDATA") or os.path.expanduser("~"),
            APP_DATA_DIR_NAME, "logs",
        )
        os.makedirs(log_dir, exist_ok=True)
        logging.basicConfig(
            level=logging.INFO,
            format="%(asctime)s %(levelname)s %(name)s: %(message)s",
            handlers=[
                logging.FileHandler(os.path.join(log_dir, "engine.log"), encoding="utf-8"),
                logging.StreamHandler(),
            ],
        )
    except Exception:
        logging.basicConfig(level=logging.INFO)

    import uvicorn
    import app.main  # noqa: F401 — import tuong minh de PyInstaller bundle du package app

    config = uvicorn.Config(app.main.app, host="127.0.0.1", port=port,
                            log_level="info", access_log=False)
    server = uvicorn.Server(config)

    parent_pid = os.environ.get("SF_PARENT_PID")
    if parent_pid:
        def _watchdog():
            pid = int(parent_pid)
            while True:
                time.sleep(1.0)
                if not _parent_alive(pid):
                    logging.getLogger("desktop_engine").info(
                        "Parent process exited — shutting down engine")
                    server.should_exit = True
                    return
        threading.Thread(target=_watchdog, daemon=True).start()

    logging.getLogger("desktop_engine").info(
        "SonicForge engine listening on 127.0.0.1:%d", port)
    server.run()


if __name__ == "__main__":
    main()