import argparse
import hashlib
import os
from pathlib import Path
import shutil
import subprocess
import sys


ROOT = Path(__file__).resolve().parent
BACKEND = ROOT / "backend"
FRONTEND = ROOT / "frontend"
VENV = ROOT / ".venv"


def install_dependencies(
    inputs: tuple[Path, ...], stamp: Path, command: list[str], cwd: Path
) -> None:
    fingerprint = hashlib.sha256()
    for path in inputs:
        fingerprint.update(hashlib.sha256(path.read_bytes()).digest())
    current = fingerprint.hexdigest()
    if stamp.is_file() and stamp.read_text(encoding="ascii") == current:
        return

    stamp.unlink(missing_ok=True)
    subprocess.run(command, cwd=cwd, check=True)
    stamp.write_text(current, encoding="ascii")


def main() -> int:
    parser = argparse.ArgumentParser(description="Локальный запуск AI-заметок.")
    parser.add_argument("--port", type=int, default=8000, help="Порт приложения (по умолчанию 8000).")
    args = parser.parse_args()
    if not 1 <= args.port <= 65535:
        parser.error("Порт должен быть от 1 до 65535.")
    if sys.version_info < (3, 11):
        parser.exit(1, "Установите Python 3.11 или новее.\n")

    npm = shutil.which("npm.cmd" if os.name == "nt" else "npm")
    if not npm or not shutil.which("node"):
        parser.exit(1, "Установите Node.js с npm и заново откройте терминал.\n")

    env_file = ROOT / ".env"
    if not env_file.exists():
        shutil.copyfile(ROOT / ".env.example", env_file)
        print("Создан .env. Для генерации добавьте ключ Groq в этот файл.", flush=True)

    python = VENV / ("Scripts/python.exe" if os.name == "nt" else "bin/python")
    if not python.is_file():
        subprocess.run([sys.executable, "-m", "venv", str(VENV)], check=True)

    install_dependencies(
        (BACKEND / "requirements.txt",),
        VENV / ".notes-dependencies",
        [str(python), "-m", "pip", "install", "-r", "requirements.txt"],
        BACKEND,
    )
    install_dependencies(
        (FRONTEND / "package.json", FRONTEND / "package-lock.json"),
        FRONTEND / "node_modules" / ".notes-dependencies",
        [npm, "ci"],
        FRONTEND,
    )
    subprocess.run([npm, "run", "build"], cwd=FRONTEND, check=True)

    return subprocess.call(
        [
            str(python), "-m", "uvicorn", "app.main:app",
            "--env-file", str(env_file), "--host", "127.0.0.1", "--port", str(args.port),
        ],
        cwd=BACKEND,
        env={**os.environ, "NOTES_WEB_DIST": str(FRONTEND / "dist")},
    )


if __name__ == "__main__":
    try:
        raise SystemExit(main())
    except subprocess.CalledProcessError as error:
        print("Запуск остановлен. Причина указана выше.", file=sys.stderr)
        raise SystemExit(error.returncode) from None
    except KeyboardInterrupt:
        raise SystemExit(130) from None