"""Runtime helpers for console-less Windows launches."""

from __future__ import annotations

import sys
import traceback
from datetime import datetime
from pathlib import Path
import tempfile
from typing import Callable, TypeVar

from version_info import module_version

__version__ = module_version(__name__)

BASE_DIR = Path(__file__).resolve().parent
FATAL_LOG = BASE_DIR / "warehouse_fatal.log"
TEMP_DIR = Path(tempfile.gettempdir())
_STDIO_HANDLES = []
T = TypeVar("T")


def _open_log_file(path: Path):
    """Open a log path, falling back to the user temp directory when needed."""

    try:
        path.parent.mkdir(parents=True, exist_ok=True)
        return path.open("a", encoding="utf-8", buffering=1)
    except Exception:
        fallback = TEMP_DIR / path.name
        fallback.parent.mkdir(parents=True, exist_ok=True)
        return fallback.open("a", encoding="utf-8", buffering=1)


def ensure_stdio(app_name: str) -> None:
    """Give ``pythonw`` a real stdout/stderr target before loggers are imported."""

    stamp = datetime.now().strftime("%Y%m%d")
    if sys.stdout is None:
        handle = _open_log_file(BASE_DIR / f"{app_name}_stdout_{stamp}.log")
        _STDIO_HANDLES.append(handle)
        sys.stdout = handle
    if sys.stderr is None:
        handle = _open_log_file(BASE_DIR / f"{app_name}_stderr_{stamp}.log")
        _STDIO_HANDLES.append(handle)
        sys.stderr = handle


def log_fatal(app_name: str, exc: BaseException) -> None:
    """Write one startup/runtime crash to a persistent log file."""

    with _open_log_file(FATAL_LOG) as handle:
        handle.write("\n" + "=" * 80 + "\n")
        handle.write(f"{datetime.now():%Y-%m-%d %H:%M:%S} | {app_name}\n")
        handle.write("".join(traceback.format_exception(type(exc), exc, exc.__traceback__)))


def log_runtime_event(app_name: str, message: str) -> None:
    """Write a lightweight launch/shutdown trace for console-less starts."""

    safe_name = "".join(ch if ch.isalnum() or ch in ("_", "-") else "_" for ch in app_name.lower())
    path = BASE_DIR / f"{safe_name}_launch.log"
    with _open_log_file(path) as handle:
        handle.write(f"{datetime.now():%Y-%m-%d %H:%M:%S} | {message}\n")


def show_fatal_message(app_name: str, exc: BaseException) -> None:
    """Show a best-effort message box for console-less launches."""

    try:
        import tkinter as tk
        from tkinter import messagebox

        root = tk.Tk()
        root.withdraw()
        messagebox.showerror(
            app_name,
            "Avvio non riuscito.\n\n"
            f"Controlla i log in:\n{BASE_DIR}\n\n"
            f"Se non ci sono, controlla anche:\n{TEMP_DIR}\n\n"
            f"{exc}",
            parent=root,
        )
        root.destroy()
    except Exception:
        pass


def run_with_fatal_log(app_name: str, func: Callable[[], T]) -> T:
    """Run an app entry point and persist otherwise invisible ``pythonw`` crashes."""

    try:
        log_runtime_event(
            app_name,
            f"START exe={sys.executable!r} version={sys.version.split()[0]} cwd={Path.cwd()} base={BASE_DIR} argv={sys.argv!r}",
        )
        result = func()
        log_runtime_event(app_name, f"RETURN result={result!r}")
        return result
    except BaseException as exc:
        log_runtime_event(app_name, f"EXCEPTION type={type(exc).__name__} value={exc!r}")
        log_fatal(app_name, exc)
        show_fatal_message(app_name, exc)
        raise