"""
MT5 路径占位符解析（不做任何自动探测）。

支持占位符:
    {PROJECT_ROOT}    项目根目录绝对路径
    {APP_DATA_DIR}    %APPDATA% (C:\\Users\\<user>\\AppData\\Roaming)
    ${APPDATA}        同上 (POSIX 风格)
    ${USERPROFILE}    C:\\Users\\<user>

留空的路径会原样返回，由调用方/用户决定。
"""

import os
from typing import Optional


PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


def _expand_placeholders(value: str, project_root: str) -> str:
    if not value:
        return value
    expanded = (
        value
        .replace("{PROJECT_ROOT}", project_root)
        .replace("{APP_DATA_DIR}", os.environ.get("APPDATA", ""))
        .replace("${APPDATA}", os.environ.get("APPDATA", ""))
        .replace("${USERPROFILE}", os.environ.get("USERPROFILE", ""))
    )
    if "{" in expanded and "}" in expanded:
        return expanded
    return os.path.normpath(expanded)


def resolve_mt5_settings(mt5_settings: dict, project_root: Optional[str] = None) -> dict:
    """只做 {PROJECT_ROOT} 等占位符替换；空值原样保留，不做任何自动探测。"""
    if project_root is None:
        project_root = PROJECT_ROOT

    resolved = dict(mt5_settings)

    for key, default_sub in (("ini_dir", os.path.join("config", "generated")),
                             ("reports_dir", "reports")):
        v = resolved.get(key, "")
        if not v:
            resolved[key] = os.path.join(project_root, default_sub)
        else:
            expanded = _expand_placeholders(v, project_root)
            if expanded and (os.path.isabs(expanded) or "{" not in expanded):
                resolved[key] = expanded
            else:
                resolved[key] = os.path.join(project_root, expanded)

    return resolved


if __name__ == "__main__":
    import pprint
    sample = {
        "terminal_path": "",
        "data_dir": "",
        "ini_dir": "{PROJECT_ROOT}/config/generated",
        "reports_dir": "{PROJECT_ROOT}/reports",
    }
    pprint.pp(resolve_mt5_settings(sample))