scholarr/app/services/domains/ingestion/fingerprints.py
2026-02-26 12:54:19 +01:00

243 lines
7.8 KiB
Python

from __future__ import annotations
import hashlib
import json
import re
from typing import Any
from urllib.parse import urljoin
from app.services.domains.ingestion.constants import (
HTML_TAG_RE,
INITIAL_PAGE_FINGERPRINT_MAX_PUBLICATIONS,
SPACE_RE,
TITLE_ALNUM_RE,
WORD_RE,
)
from app.services.domains.scholar.parser import ParseState, ParsedProfilePage, PublicationCandidate
# Scholar-specific noise patterns stripped before canonical comparison.
# Applied in order; each targets a different Scholar metadata injection style.
_NOISE_DOI_RE = re.compile(r"[,.\s]+doi\s*:\s*\S+.*$", re.IGNORECASE)
_NOISE_ARXIV_RE = re.compile(r"[,.\s]+arxiv\b.*$", re.IGNORECASE)
_NOISE_PREPRINT_RE = re.compile(
r"[,\s]+(?:preprint|extended\s+version|technical\s+report|working\s+paper)\b.*$",
re.IGNORECASE,
)
_NOISE_TRAILING_YEAR_RE = re.compile(r"\s*[,(]\s*\d{4}\s*[),]?\s*$")
# Strips ". Capitalised sentence" appended as venue: ". Comput. Sci…", ". Journal of…"
_NOISE_VENUE_SENTENCE_RE = re.compile(r"(?<=\w{3})\.\s+[A-Z][a-z].*$")
_CANONICAL_DEDUP_THRESHOLD = 0.82
def normalize_title(value: str) -> str:
lowered = value.lower()
return TITLE_ALNUM_RE.sub("", lowered)
def canonical_title_for_dedup(title: str) -> str:
"""Strip Scholar-specific noise suffixes then normalize for dedup comparison."""
t = title.strip()
t = _NOISE_DOI_RE.sub("", t)
t = _NOISE_ARXIV_RE.sub("", t)
t = _NOISE_PREPRINT_RE.sub("", t)
t = _NOISE_TRAILING_YEAR_RE.sub("", t)
t = _NOISE_VENUE_SENTENCE_RE.sub("", t)
return normalize_title(t.strip())
def _stripped_title_for_canonical(title: str) -> str:
"""Apply noise-stripping and lowercase but PRESERVE spaces (for later tokenization)."""
t = title.strip()
t = _NOISE_DOI_RE.sub("", t)
t = _NOISE_ARXIV_RE.sub("", t)
t = _NOISE_PREPRINT_RE.sub("", t)
t = _NOISE_TRAILING_YEAR_RE.sub("", t)
t = _NOISE_VENUE_SENTENCE_RE.sub("", t)
return t.lower().strip()
def _canonical_title_tokens(title: str) -> set[str]:
"""Word tokens of the noise-stripped title (preserves token boundaries)."""
return set(WORD_RE.findall(_stripped_title_for_canonical(title)))
def _jaccard(a: set[str], b: set[str]) -> float:
if not a or not b:
return 0.0
return len(a & b) / len(a | b)
def _first_author_last_name(authors_text: str | None) -> str:
if not authors_text:
return ""
first_author = authors_text.split(",", maxsplit=1)[0].strip().lower()
words = WORD_RE.findall(first_author)
if not words:
return ""
return words[-1]
def _first_venue_word(venue_text: str | None) -> str:
if not venue_text:
return ""
words = WORD_RE.findall(venue_text.lower())
if not words:
return ""
return words[0]
def build_publication_fingerprint(candidate: PublicationCandidate) -> str:
canonical = "|".join(
[
normalize_title(candidate.title),
str(candidate.year) if candidate.year is not None else "",
_first_author_last_name(candidate.authors_text),
_first_venue_word(candidate.venue_text),
]
)
return hashlib.sha256(canonical.encode("utf-8")).hexdigest()
def build_initial_page_fingerprint(parsed_page: ParsedProfilePage) -> str | None:
if parsed_page.state not in {ParseState.OK, ParseState.NO_RESULTS}:
return None
normalized_rows: list[dict[str, Any]] = []
for publication in parsed_page.publications[:INITIAL_PAGE_FINGERPRINT_MAX_PUBLICATIONS]:
normalized_rows.append(
{
"cluster_id": publication.cluster_id or "",
"title_normalized": normalize_title(publication.title),
"year": publication.year,
"citation_count": publication.citation_count,
}
)
payload = {
"state": parsed_page.state.value,
"articles_range": parsed_page.articles_range or "",
"has_show_more_button": parsed_page.has_show_more_button,
"profile_name": parsed_page.profile_name or "",
"publications": normalized_rows,
}
canonical = json.dumps(
payload,
sort_keys=True,
separators=(",", ":"),
ensure_ascii=True,
)
return hashlib.sha256(canonical.encode("utf-8")).hexdigest()
def build_publication_url(path_or_url: str | None) -> str | None:
if not path_or_url:
return None
return urljoin("https://scholar.google.com", path_or_url)
def _next_cstart_value(*, articles_range: str | None, fallback: int) -> int:
if articles_range:
numbers = re.findall(r"\d+", articles_range)
if len(numbers) >= 2:
try:
return int(numbers[1])
except ValueError:
pass
return int(fallback)
def _title_tokens(value: str) -> set[str]:
"""Extract normalized word tokens for fuzzy title comparison."""
return set(WORD_RE.findall(value.lower()))
def fuzzy_titles_match(
title_a: str,
title_b: str,
*,
threshold: float = 0.85,
) -> bool:
"""Return True if two titles are near-duplicates by token-level Jaccard similarity.
A threshold of 0.85 catches common academic duplicate patterns:
differences in punctuation, minor word variations, subtitle changes.
"""
tokens_a = _title_tokens(title_a)
tokens_b = _title_tokens(title_b)
return _jaccard(tokens_a, tokens_b) >= threshold
def _dedupe_publication_candidates(
publications: list[PublicationCandidate],
*,
seen_canonical: set[str] | None = None,
) -> list[PublicationCandidate]:
"""Deduplicate candidates using canonical title matching.
Args:
publications: candidates to filter
seen_canonical: optional mutable set shared across pages. Stores the
noise-stripped *lowercased* (but space-preserved) canonical string
so it can be tokenized on the next page for cross-page fuzzy dedup.
Accepted canonicals are added; existing entries are consulted.
"""
deduped: list[PublicationCandidate] = []
seen_exact: set[str] = set()
# Token sets for fuzzy comparison; seeded from cross-page state.
seen_tokens: list[set[str]] = []
if seen_canonical:
for stripped in seen_canonical:
seen_tokens.append(set(WORD_RE.findall(stripped)))
for pub in publications:
identity = _publication_identity(pub)
if identity in seen_exact:
continue
# Use space-preserving stripped form for token-level fuzzy match.
tokens = _canonical_title_tokens(pub.title)
if _is_fuzzy_dup(tokens, seen_tokens):
continue
seen_exact.add(identity)
seen_tokens.append(tokens)
if seen_canonical is not None:
# Store the noise-stripped lowercased (space-preserved) form.
seen_canonical.add(_stripped_title_for_canonical(pub.title))
deduped.append(pub)
return deduped
def _publication_identity(pub: PublicationCandidate) -> str:
if pub.cluster_id:
return f"cluster:{pub.cluster_id}"
canonical = canonical_title_for_dedup(pub.title)
return "|".join(
[
"fallback",
canonical,
str(pub.year) if pub.year is not None else "",
_first_author_last_name(pub.authors_text),
]
)
def _is_fuzzy_dup(tokens: set[str], seen: list[set[str]]) -> bool:
for existing in seen:
if _jaccard(tokens, existing) >= _CANONICAL_DEDUP_THRESHOLD:
return True
return False
def _build_body_excerpt(body: str, *, max_chars: int = 220) -> str | None:
if not body:
return None
flattened = SPACE_RE.sub(" ", HTML_TAG_RE.sub(" ", body)).strip()
if not flattened:
return None
if len(flattened) <= max_chars:
return flattened
return f"{flattened[:max_chars - 1]}..."