from __future__ import annotations

import os
import re
import shutil
import subprocess
import sys
from pathlib import Path
from typing import Literal

WINDOWS_RESERVED_NAMES = {
    "CON",
    "PRN",
    "AUX",
    "NUL",
    *(f"COM{number}" for number in range(1, 10)),
    *(f"LPT{number}" for number in range(1, 10)),
}


class WindowsLabelError(ValueError):
    pass


def windows_filename_problems(value: str) -> list[str]:
    problems = []
    forbidden = sorted({character for character in value if character in '<>:"/\\|?*'})
    if forbidden:
        problems.append("caractères interdits " + " ".join(repr(char) for char in forbidden))
    if any(ord(character) < 32 for character in value):
        problems.append("caractère de contrôle")
    if value.endswith((" ", ".")):
        problems.append("espace ou point final")
    if not value or value in {".", ".."}:
        problems.append("nom vide ou réservé")
    elif value.split(".", 1)[0].upper() in WINDOWS_RESERVED_NAMES:
        problems.append("nom système réservé")
    return problems


def validate_windows_labels(
    labels: list[str] | tuple[str, ...], platform_name: str | None = None
) -> None:
    """Reject labels that cannot be used as filenames on native Windows."""
    if (platform_name or os.name) != "nt":
        return
    invalid = []
    for label in labels:
        problems = windows_filename_problems(label)
        if problems:
            invalid.append((label, problems))
    if not invalid:
        return
    details = "\n".join(
        f"  - {label!r}: {', '.join(problems)}" for label, problems in invalid
    )
    raise WindowsLabelError(
        "Labels incompatibles avec Windows :\n"
        f"{details}\n"
        "Modifiez ces labels avant de poursuivre (par exemple, remplacez ':' par ' - ')."
    )


def safe_filename(value: str, fallback: str = "Unknown") -> str:
    """Return a filename component accepted by both Linux and Windows."""
    cleaned = re.sub(r'[<>:"/\\|?*\x00-\x1f]', "", value).strip().rstrip(". ")
    if not cleaned:
        cleaned = fallback
    if cleaned.split(".", 1)[0].upper() in WINDOWS_RESERVED_NAMES:
        cleaned = f"_{cleaned}"
    return cleaned


def open_path(path: str | Path) -> None:
    """Open a file with the desktop's default application."""
    target = str(Path(path).expanduser().resolve())
    if os.name == "nt":
        os.startfile(target)  # type: ignore[attr-defined]
    elif sys.platform.startswith("linux"):
        subprocess.Popen(["xdg-open", target])
    else:
        raise RuntimeError(f"Unsupported platform: {sys.platform}")


def launch_pdf_arranger(path: str | Path) -> None:
    executable = shutil.which("pdf-arranger") or shutil.which("pdfarranger")
    if not executable:
        raise FileNotFoundError(
            "PDF Arranger is not installed or is not available in PATH."
        )
    subprocess.Popen([executable, str(Path(path).expanduser().resolve())])


def replace_with_link_or_copy(
    source: str | Path,
    destination: str | Path,
    *,
    prefer: Literal["hardlink", "symlink"] = "hardlink",
) -> str:
    """Replace destination with a link, falling back to a regular copy."""
    source_path = Path(source).expanduser().resolve()
    destination_path = Path(destination).expanduser()
    destination_path.parent.mkdir(parents=True, exist_ok=True)

    if os.path.lexists(destination_path):
        destination_path.unlink()

    strategies = (prefer, "symlink" if prefer == "hardlink" else "hardlink")
    for strategy in strategies:
        try:
            if strategy == "hardlink":
                os.link(source_path, destination_path)
            else:
                os.symlink(source_path, destination_path)
            return strategy
        except (NotImplementedError, OSError):
            continue

    shutil.copy2(source_path, destination_path)
    return "copy"