"""
内容搜索缓存（磁盘持久化）

搜索结果按 trace_id 隔离，同一 Agent session 内的 CLI 多次调用也能复用。
文件格式：/tmp/content_cache_{trace_id}.json
"""

import json
import os
import time
from pathlib import Path
from typing import Any, Dict, List, Optional

_CACHE_DIR = Path("/tmp")
_CACHE_TTL = 3600  # 1 小时过期


def _cache_path(trace_id: str) -> Path:
    safe_id = trace_id.replace("/", "_").replace("..", "_")
    return _CACHE_DIR / f"content_cache_{safe_id}.json"


def _load_raw(trace_id: str) -> dict:
    p = _cache_path(trace_id)
    if not p.exists():
        return {}
    try:
        data = json.loads(p.read_text("utf-8"))
        # 检查过期
        if time.time() - data.get("_ts", 0) > _CACHE_TTL:
            p.unlink(missing_ok=True)
            return {}
        return data
    except Exception:
        return {}


def _save_raw(trace_id: str, data: dict) -> None:
    data["_ts"] = time.time()
    try:
        _cache_path(trace_id).write_text(
            json.dumps(data, ensure_ascii=False), encoding="utf-8"
        )
    except Exception:
        pass


def save_search_results(
    trace_id: str,
    platform: str,
    keyword: str,
    posts: List[Dict[str, Any]],
) -> None:
    """保存搜索结果到磁盘缓存"""
    data = _load_raw(trace_id)
    # 每个 platform 只保留最近一次搜索
    data[f"search:{platform}"] = {
        "keyword": keyword,
        "posts": posts,
    }
    _save_raw(trace_id, data)


def get_cached_post(
    trace_id: str,
    platform: str,
    index: int,
) -> Optional[Dict[str, Any]]:
    """按索引从缓存取一条完整记录（1-based）"""
    data = _load_raw(trace_id)
    entry = data.get(f"search:{platform}")
    if not entry:
        return None
    posts = entry.get("posts", [])
    if 1 <= index <= len(posts):
        return posts[index - 1]
    return None


def get_cached_search_info(trace_id: str, platform: str) -> Optional[Dict[str, Any]]:
    """获取缓存的搜索信息（keyword + 总条数），用于错误提示"""
    data = _load_raw(trace_id)
    entry = data.get(f"search:{platform}")
    if not entry:
        return None
    return {"keyword": entry.get("keyword"), "total": len(entry.get("posts", []))}