File size: 5,308 Bytes
5543737
817d4c6
5543737
 
f051f2e
817d4c6
 
 
 
 
 
5543737
817d4c6
 
 
 
 
 
 
 
 
 
 
 
5543737
817d4c6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5543737
817d4c6
 
 
f051f2e
1e3e62c
5543737
 
 
 
 
 
 
5daa3d4
5543737
1e3e62c
817d4c6
f051f2e
817d4c6
5543737
 
817d4c6
5543737
817d4c6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5543737
817d4c6
 
 
 
 
 
 
 
 
 
 
 
5543737
 
 
 
 
 
 
 
817d4c6
 
 
 
 
 
f051f2e
817d4c6
 
 
 
 
5543737
817d4c6
 
 
5daa3d4
5543737
 
 
 
 
 
5daa3d4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
817d4c6
 
 
 
 
5543737
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
# session_rag.py
from __future__ import annotations
import logging, hashlib
from typing import Iterable, List, Optional, Dict, Any
import numpy as np
from sentence_transformers import SentenceTransformer

try:
    import faiss  # type: ignore
    _HAS_FAISS = True
except Exception:
    logging.warning("FAISS not installed — using NumPy cosine fallback.")
    faiss = None  # type: ignore
    _HAS_FAISS = False

def _normalize_rows(x: np.ndarray) -> np.ndarray:
    norms = np.linalg.norm(x, axis=1, keepdims=True) + 1e-10
    return x / norms

def _hash_text(s: str) -> str:
    return hashlib.sha256(s.encode("utf-8")).hexdigest()

def _coerce_texts(items: Iterable) -> List[str]:
    out: List[str] = []
    seen = set()
    for it in items or []:
        if isinstance(it, str):
            txt = it.strip()
        elif isinstance(it, dict):
            txt = (it.get("text") or it.get("content") or "").strip()
        else:
            txt = ""
        if not txt:
            continue
        h = _hash_text(txt)
        if h in seen:
            continue
        seen.add(h)
        out.append(txt)
    return out

def _simple_chunk(text: str, max_chars: int = 1200, overlap: int = 150) -> List[str]:
    if len(text) <= max_chars:
        return [text]
    chunks = []
    i = 0
    while i < len(text):
        chunks.append(text[i : i + max_chars])
        i += max_chars - overlap
    return chunks

class SessionRAG:
    """
    Ephemeral per-session retriever with artifact registry.

    Public:
      - add_docs(items)
      - register_artifacts(arts)
      - retrieve(query, k=5)
      - get_latest_csv_columns()
      - get_csv_summaries()
      - clear()
    """
    def __init__(self, model_name: str = "all-MiniLM-L6-v2"):
        self.model = SentenceTransformer(model_name)
        self.texts: List[str] = []
        self.embeddings: Optional[np.ndarray] = None
        self.index = None
        self.dim: Optional[int] = None
        self.artifacts: List[Dict[str, Any]] = []  # keeps structured info per upload

    def _fit_faiss(self) -> None:
        if not _HAS_FAISS or self.embeddings is None:
            return
        emb = _normalize_rows(self.embeddings.astype("float32"))
        self.dim = emb.shape[1]
        self.index = faiss.IndexFlatIP(self.dim)
        self.index.add(emb)

    def _ensure_embeddings(self) -> None:
        if not self.texts:
            self.embeddings = None
            self.index = None
            return
        embs = self.model.encode(self.texts, batch_size=64, show_progress_bar=False)
        self.embeddings = np.asarray(embs, dtype="float32")
        if _HAS_FAISS:
            self._fit_faiss()
        else:
            self.index = None

    def add_docs(self, items: Iterable) -> int:
        raw_texts = _coerce_texts(items)
        if not raw_texts:
            return 0
        chunks: List[str] = []
        for t in raw_texts:
            chunks.extend(_simple_chunk(t))
        existing_hashes = {_hash_text(t) for t in self.texts}
        added = 0
        for c in chunks:
            h = _hash_text(c)
            if h in existing_hashes:
                continue
            self.texts.append(c)
            existing_hashes.add(h)
            added += 1
        if added > 0:
            self._ensure_embeddings()
        return added

    def register_artifacts(self, arts: Iterable[Dict[str, Any]]) -> int:
        count = 0
        for a in (arts or []):
            if isinstance(a, dict):
                self.artifacts.append(a)
                count += 1
        return count

    def retrieve(self, query: str, k: int = 5) -> List[str]:
        if not query or not self.texts:
            return []
        q_emb = self.model.encode([query], show_progress_bar=False)
        q = _normalize_rows(np.asarray(q_emb, dtype="float32"))
        if self.embeddings is None:
            return []
        if _HAS_FAISS and self.index is not None:
            D, I = self.index.search(q, min(k, len(self.texts)))
            idxs = [i for i in I[0] if 0 <= i < len(self.texts)]
            return [self.texts[i] for i in idxs]
        docs = _normalize_rows(self.embeddings)
        sims = (q @ docs.T)[0]
        top_idx = np.argsort(-sims)[: min(k, len(self.texts))]
        return [self.texts[i] for i in top_idx]

    # ---------- helpers for structured data ----------
    def get_latest_csv_columns(self) -> List[str]:
        for a in reversed(self.artifacts):
            if a.get("kind") == "csv" and a.get("columns"):
                return list(map(str, a["columns"]))
        return []

    def get_csv_summaries(self) -> List[Dict[str, Any]]:
        """
        Return a list of dicts with keys:
          - file (str)
          - digest (str)
          - summary (dict)
        newest-first
        """
        out: List[Dict[str, Any]] = []
        for a in reversed(self.artifacts):
            if a.get("kind") == "csv_summary":
                out.append({
                    "file": a.get("name"),
                    "digest": a.get("digest"),
                    "summary": a.get("summary"),
                })
        return out

    def clear(self) -> None:
        self.texts = []
        self.embeddings = None
        self.index = None
        self.dim = None
        self.artifacts = []