File size: 5,588 Bytes
16fa4e7
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
168
169
170
171
172
173
174
"""Load PDFs, split into chunks with metadata, and index into Qdrant."""

from __future__ import annotations

import hashlib
import uuid
from collections import defaultdict
from pathlib import Path
from typing import Protocol

from langchain_community.document_loaders import PyPDFLoader
from langchain_core.documents import Document
from langchain_text_splitters import RecursiveCharacterTextSplitter
from loguru import logger

from src.config import settings
from src.schemas import ChunkMetadata
from src.store import ensure_collection, get_vector_store


class Chunker(Protocol):
    def split_documents(self, documents: list[Document]) -> list[Document]:
        """Split page-level documents into chunk-level documents."""


def _splitter(
    chunk_size: int | None = None, chunk_overlap: int | None = None
) -> RecursiveCharacterTextSplitter:
    size = chunk_size or settings.chunk_size
    overlap = chunk_overlap or settings.chunk_overlap

    return RecursiveCharacterTextSplitter(
        chunk_size=size,
        chunk_overlap=overlap,
        separators=["\n\n", "\n", ". ", " ", ""],
        keep_separator=False,
    )


def _document_id(path: Path) -> str:
    raw = f"{path.name}:{path.stat().st_size}"
    return hashlib.sha1(raw.encode("utf-8")).hexdigest()[:16]


def _chunk_id(doc_id: str, page: int, index: int) -> str:
    return f"{doc_id}:{page}:{index}"


def _load_pdf(path: Path) -> list[Document]:
    loader = PyPDFLoader(str(path))
    pages = loader.load()
    doc_id = _document_id(path)
    for doc in pages:
        page_number = int(doc.metadata.get("page", 0)) + 1
        doc.metadata = {
            "document_id": doc_id,
            "filename": path.name,
            "source": str(path.resolve()),
            "page": page_number,
            "section": doc.metadata.get("section"),
        }
    return pages


def discover_pdfs(data_dir: Path | None = None) -> list[Path]:
    directory = data_dir or settings.data_dir
    if not directory.exists():
        return []
    return sorted(p for p in directory.iterdir() if p.is_file() and p.suffix.lower() == ".pdf")


def build_chunks(
    pdf_paths: list[Path],
    chunk_size: int | None = None,
    chunk_overlap: int | None = None,
    chunker: Chunker | None = None,
) -> list[Document]:
    page_docs: list[Document] = []
    for path in pdf_paths:
        logger.info("Loading PDF: {}", path.name)
        page_docs.extend(_load_pdf(path))

    if chunker is None:
        chunks = _splitter(chunk_size, chunk_overlap).split_documents(page_docs)
    else:
        chunks = chunker.split_documents(page_docs)

    per_doc_counter: dict[str, int] = defaultdict(int)
    for chunk in chunks:
        doc_id = chunk.metadata["document_id"]
        idx = per_doc_counter[doc_id]
        per_doc_counter[doc_id] += 1
        meta = ChunkMetadata(
            document_id=doc_id,
            filename=chunk.metadata["filename"],
            source=chunk.metadata["source"],
            page=chunk.metadata["page"],
            chunk_id=_chunk_id(doc_id, chunk.metadata["page"], idx),
            section=chunk.metadata.get("section"),
        )
        chunk.metadata = meta.model_dump()
    return chunks


def index_chunks(chunks: list[Document], collection_name: str | None = None) -> int:
    """Compute deterministic UUIDs and add chunks to the vector store.

    Re-ingesting the same content upserts instead of creating duplicates.
    """
    if not chunks:
        return 0
    ids = [str(uuid.uuid5(uuid.NAMESPACE_DNS, c.metadata["chunk_id"])) for c in chunks]
    get_vector_store(collection_name=collection_name).add_documents(chunks, ids=ids)
    return len(chunks)


def ingest(
    recreate: bool = False,
    collection_name: str | None = None,
    chunker: Chunker | None = None,
    chunk_size: int | None = None,
    chunk_overlap: int | None = None,
) -> int:
    pdfs = discover_pdfs()
    if not pdfs:
        logger.warning("No PDF files found in {}", settings.data_dir)
        return 0

    ensure_collection(recreate=recreate, collection_name=collection_name)
    chunks = build_chunks(
        pdfs,
        chunker=chunker,
        chunk_size=chunk_size,
        chunk_overlap=chunk_overlap,
    )

    if not chunks:
        logger.warning("No chunks produced from {} PDF(s)", len(pdfs))
        return 0

    count = index_chunks(chunks, collection_name=collection_name)
    logger.info("Ingested {} chunks from {} PDF(s)", count, len(pdfs))
    return count


def save_and_ingest_pdf(file_bytes: bytes, filename: str) -> dict[str, object]:
    """Save an uploaded PDF to `data_dir` and ingest it into Qdrant.

    Args: file_bytes, filename. Returns: {"filename", "chunks_indexed"}. Raises: ValueError.
    """
    if not filename:
        raise ValueError("Filename is required.")
    if not filename.lower().endswith(".pdf"):
        raise ValueError("Only PDF files are accepted.")
    if not file_bytes:
        raise ValueError("Uploaded file is empty.")

    safe_name = Path(filename).name
    settings.data_dir.mkdir(parents=True, exist_ok=True)
    dest = settings.data_dir / safe_name
    dest.write_bytes(file_bytes)
    logger.info("Saved uploaded PDF: {}", dest)

    ensure_collection(recreate=False)
    chunks = build_chunks([dest])
    if not chunks:
        logger.warning("No chunks produced for uploaded file {}", safe_name)
        return {"filename": safe_name, "chunks_indexed": 0}

    count = index_chunks(chunks)
    logger.info("Indexed {} chunks from {}", count, safe_name)
    return {"filename": safe_name, "chunks_indexed": count}