import os
import platform
import winreg


def get_qgis_install_dir():
    # 尝试从环境变量获取
    qgis_env = os.getenv('QGIS_PREFIX_PATH')
    if qgis_env:
        return f'{qgis_env.replace("apps/qgis-ltr","")}bin'
    # 尝试从Windows注册表获取
    if platform.system() == "Windows":
        sub_key = winreg.OpenKey(winreg.HKEY_CURRENT_USER, r'Software\QGIS')
        try:
            qgis_dir, _ = winreg.QueryValueEx(sub_key, 'QGIS_PREFIX_PATH')
            return qgis_dir
        except WindowsError:
            pass
    # 常见的安装路径
    default_paths = [
        os.path.join(os.path.expanduser('~'), 'AppData\Local\QGIS\QGIS3'),
        r'C:\Program Files\QGIS 3.X',
        r'C:\Program Files (x86)\QGIS 3.X',
    ]
    for path in default_paths:
        if os.path.exists(path):
            return path
    return None

# 使用函数
qgis_dir = get_qgis_install_dir()
print(f"QGIS Install Directory: {qgis_dir}")