"""
PyInstaller 运行时钩子：固定 MSVC 运行库加载顺序，再注册 DLL 搜索路径。

打包阶段在 strip 掉各 wheel 自带 CRT 后，会 **仅嵌入** 构建所用 Python ``DLLs``
下的 ``vcruntime140.dll`` / ``vcruntime140_1.dll`` / ``msvcp140.dll`` 至 ``_MEIPASS``。
本钩子在导入 chroma/torch 等扩展 **之前**，用 ``ctypes.WinDLL(绝对路径)`` 从 **同一目录**
（优先 exe 旁若用户自行放置了完整三件套，否则 ``_MEIPASS``）预加载，避免进程落到
目标机 ``System32`` 里较旧版本（如 14.29）再与 native 扩展不兼容触发 ``0xc0000005``。

随后再 ``add_dll_directory`` exe 目录与 ``_MEIPASS``，并调整 ``PATH``。不使用 ``SetDllDirectoryW``。
"""


def _preload_msvc_crt_once():
    """若 exe 目录或 ``_MEIPASS`` 下存在 ``msvcp140.dll``，则按依赖顺序预加载该目录内 CRT。"""
    import ctypes
    import sys
    from pathlib import Path

    if sys.platform != "win32" or not getattr(sys, "frozen", False):
        return

    order = ("vcruntime140.dll", "vcruntime140_1.dll", "msvcp140.dll")
    search_dirs = []
    try:
        exe_parent = Path(sys.executable).resolve().parent
        search_dirs.append(exe_parent)
    except OSError:
        pass
    meipass = getattr(sys, "_MEIPASS", None)
    if meipass:
        search_dirs.append(Path(meipass))

    for d in search_dirs:
        if not d.is_dir():
            continue
        if not (d / "msvcp140.dll").is_file():
            continue
        for name in order:
            p = d / name
            if p.is_file():
                try:
                    ctypes.WinDLL(str(p))
                except OSError:
                    pass
        return


def _apply_dll_search_paths():
    """将 exe 目录与 ``_MEIPASS`` 注册为 DLL 目录，并置于 PATH 最前（exe 目录优先）。"""
    import os
    import sys
    from pathlib import Path

    if not getattr(sys, "frozen", False):
        return

    dirs = []
    try:
        exe_dir = str(Path(sys.executable).resolve().parent)
        if exe_dir:
            dirs.append(exe_dir)
    except OSError:
        pass

    meipass = getattr(sys, "_MEIPASS", None)
    if meipass:
        dirs.append(meipass)

    for d in dirs:
        if not d:
            continue
        try:
            if hasattr(os, "add_dll_directory"):
                os.add_dll_directory(d)
        except OSError:
            pass

    path = os.environ.get("PATH", "")
    prefix = os.pathsep.join([d for d in dirs if d])
    if not prefix:
        return
    if path.startswith(prefix):
        return
    os.environ["PATH"] = f"{prefix}{os.pathsep}{path}"


_preload_msvc_crt_once()
_apply_dll_search_paths()