"""浏览采集：取消标记与增量落盘（供 GUI 停止后返回已采数据）。"""

from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any


def _path_from_env(key: str) -> Path | None:
    raw = (os.environ.get(key) or "").strip()
    return Path(raw) if raw else None


def clear_session() -> None:
    """重置增量落盘；取消标记由 GUI 在 browse 会话中单独管理。"""
    partial = _path_from_env("XHS_PARTIAL_FEEDS_FILE")
    if partial:
        partial.parent.mkdir(parents=True, exist_ok=True)
        partial.write_text(json.dumps({"feeds": []}, ensure_ascii=False), encoding="utf-8")


def request_cancel() -> None:
    cancel = _path_from_env("XHS_CANCEL_FILE")
    if cancel:
        cancel.parent.mkdir(parents=True, exist_ok=True)
        cancel.write_text("1", encoding="utf-8")


def is_cancelled() -> bool:
    cancel = _path_from_env("XHS_CANCEL_FILE")
    return bool(cancel and cancel.exists())


def persist_collected(collected: dict[str, dict]) -> None:
    partial = _path_from_env("XHS_PARTIAL_FEEDS_FILE")
    if not partial:
        return
    payload = {"feeds": list(collected.values())}
    partial.parent.mkdir(parents=True, exist_ok=True)
    partial.write_text(json.dumps(payload, ensure_ascii=False), encoding="utf-8")


def load_partial_feeds() -> list[dict[str, Any]]:
    partial = _path_from_env("XHS_PARTIAL_FEEDS_FILE")
    if not partial or not partial.is_file():
        return []
    try:
        data = json.loads(partial.read_text(encoding="utf-8"))
    except (json.JSONDecodeError, OSError):
        return []
    feeds = data.get("feeds") if isinstance(data, dict) else data
    return feeds if isinstance(feeds, list) else []


def raise_if_cancelled() -> None:
    from .errors import BrowseCancelledError

    if is_cancelled():
        raise BrowseCancelledError()