#!/usr/bin/env python3
"""
Verify Python version, OS, and required packages before running the toolchain.

Usage:
    python check_deps.py
"""

from __future__ import annotations  # allows str | None syntax on Python < 3.10

import importlib.metadata
import sys

# Must not import arma_modlist_tools here — that's what we're checking FOR.

MIN_PYTHON = (3, 9)
REQUIRED_PACKAGES = ["requests", "tqdm"]


def _python_ok() -> bool:
    return sys.version_info >= MIN_PYTHON


def _get_os_label() -> str:
    """Inline OS detection — avoids importing compat before deps are confirmed."""
    import platform
    if sys.platform == "win32":
        if "Server" in platform.version() or "Server" in platform.uname().version:
            return "Windows Server"
        return "Windows"
    if sys.platform == "linux":
        try:
            with open("/etc/os-release", encoding="utf-8") as f:
                text = f.read().lower()
            if "ubuntu" in text:
                import os
                headless = not (os.environ.get("DISPLAY") or os.environ.get("WAYLAND_DISPLAY"))
                return "Ubuntu Server" if headless else "Ubuntu"
        except OSError:
            pass
        return "Linux"
    return "Unknown"


def _pkg_version(name: str) -> str | None:
    try:
        return importlib.metadata.version(name)
    except importlib.metadata.PackageNotFoundError:
        return None


def main() -> None:
    print()

    # Python version
    ver = sys.version.split()[0]
    py_ok = _python_ok()
    status = "OK" if py_ok else f"NEED >= {MIN_PYTHON[0]}.{MIN_PYTHON[1]}"
    print(f"  {'Python':<14} {ver:<12}  {status}")

    # OS
    os_label = _get_os_label()
    print(f"  {'OS':<14} {os_label}")
    print()

    # Packages
    missing = []
    for pkg in REQUIRED_PACKAGES:
        v = _pkg_version(pkg)
        if v:
            print(f"  {pkg:<14} {v:<12}  OK")
        else:
            print(f"  {pkg:<14} {'---':<12}  MISSING")
            missing.append(pkg)

    print()

    if not py_ok:
        print(f"  Python {MIN_PYTHON[0]}.{MIN_PYTHON[1]}+ is required.")
        sys.exit(1)

    if missing:
        print(f"  {len(missing)} package(s) missing. Install with:")
        print(f"    pip install {' '.join(missing)}")
        print()
        print("  Run check_deps.py again to verify.")
        sys.exit(1)

    print("  All checks passed. Ready to run.")
    print()


if __name__ == "__main__":
    main()