"""
id: rag
title: Lightweight RAG
author: admin
description: Store documents and retrieve by simple keyword scoring.
version: 0.1.0
license: Proprietary
"""

import json
import re
import time
from pathlib import Path

ROOT = Path("/data/adaptai/rag")
ROOT.mkdir(parents=True, exist_ok=True)
INDEX = ROOT / "index.json"


class Tools:
    def add_text(self, text: str, doc_id: str = "") -> dict:
        doc_id = doc_id or f"doc_{int(time.time())}"
        (ROOT / f"{doc_id}.txt").write_text(text, encoding="utf-8")
        self._reindex()
        return {"ok": True, "doc_id": doc_id}

    def add_file(self, path: str, doc_id: str = "") -> dict:
        p = Path(path)
        if not p.exists():
            return {"ok": False, "error": "file not found"}
        text = p.read_text(encoding="utf-8", errors="replace")
        return self.add_text(text, doc_id)

    def query(self, q: str, top_k: int = 5) -> dict:
        idx = self._load_index()
        tokens = self._tok(q)
        scored = []
        for doc_id, dt in idx.items():
            score = sum(dt.get(t, 0) for t in tokens)
            if score:
                scored.append((score, doc_id))
        scored.sort(reverse=True)
        hits = []
        for score, doc_id in scored[:top_k]:
            text = (ROOT / f"{doc_id}.txt").read_text(
                encoding="utf-8", errors="replace"
            )
            hits.append({"doc_id": doc_id, "score": score, "preview": text[:400]})
        return {"query": q, "hits": hits}

    def list(self) -> dict:
        idx = self._load_index()
        return {"docs": list(idx.keys())}

    def remove(self, doc_id: str) -> dict:
        try:
            (ROOT / f"{doc_id}.txt").unlink(missing_ok=True)
            self._reindex()
            return {"ok": True}
        except Exception as e:
            return {"ok": False, "error": str(e)}

    def _tok(self, s: str):
        s = s.lower()
        return re.findall(r"[a-z0-9]+", s)

    def _reindex(self):
        idx = {}
        for f in ROOT.glob("*.txt"):
            counts = {}
            for t in self._tok(f.read_text(encoding="utf-8", errors="replace")):
                counts[t] = counts.get(t, 0) + 1
            idx[f.stem] = counts
        INDEX.write_text(json.dumps(idx), encoding="utf-8")

    def _load_index(self):
        if not INDEX.exists():
            return {}
        return json.loads(INDEX.read_text(encoding="utf-8"))