"""PortAudio/PyAudio 启动前调整动态库搜索路径。

conda 环境下 `.../envs/xxx/lib` 里的 libasound 会到同前缀的 alsa-lib 子目录找插件，
该目录常缺 libasound_module_*.so，日志里刷屏且采集电平可能异常。

处理：1) 去掉仅含插件目录的路径；2) 把系统 /usr/lib/<triplet> 插到 LD_LIBRARY_PATH 最前，
让动态链接优先用系统的 libasound。"""
from __future__ import annotations

import os
import platform


def strip_conda_alsa_from_ld_library_path() -> None:
    ld = os.environ.get("LD_LIBRARY_PATH", "")
    if not ld:
        return
    parts: list[str] = []
    for p in ld.split(":"):
        if not p:
            continue
        pl = p.lower()
        if "conda" in pl or "miniconda" in pl or "mamba" in pl:
            if "alsa-lib" in pl or "alsa_lib" in pl:
                continue
        parts.append(p)
    if parts:
        os.environ["LD_LIBRARY_PATH"] = ":".join(parts)
    else:
        os.environ.pop("LD_LIBRARY_PATH", None)


def prepend_system_lib_dirs_for_alsa() -> None:
    """Linux：把系统 lib 目录放在 LD_LIBRARY_PATH 最前面。"""
    if platform.system() != "Linux":
        return
    triplet = {
        "aarch64": ("/usr/lib/aarch64-linux-gnu", "/lib/aarch64-linux-gnu"),
        "x86_64": ("/usr/lib/x86_64-linux-gnu", "/lib/x86_64-linux-gnu"),
        "amd64": ("/usr/lib/x86_64-linux-gnu", "/lib/x86_64-linux-gnu"),
    }.get(platform.machine().lower())
    if not triplet:
        return
    prepend: list[str] = []
    for d in triplet:
        if os.path.isdir(d):
            prepend.append(d)
    if not prepend:
        return
    rest = [p for p in os.environ.get("LD_LIBRARY_PATH", "").split(":") if p]
    out: list[str] = []
    for p in prepend + rest:
        if p not in out:
            out.append(p)
    os.environ["LD_LIBRARY_PATH"] = ":".join(out)


def fix_ld_path_for_portaudio() -> None:
    prepend_system_lib_dirs_for_alsa()
    strip_conda_alsa_from_ld_library_path()