pdf-quiz-generator/backend/app/tasks/quiz_tasks.py
Daniel e5e31f6eba Two-phase extraction for end-of-document answer keys (PREP 2013); scroll fix; bug audit
Two-phase extraction:
- Detects end-of-document answer key format by scanning last 40 pages for
  "Preferred Response:" (PREP 2013, 2014 etc use this vs PREP 2012 inline "Correct Answer:")
- Phase 1: Extract questions with item_number field, allow null correct_answer
- Phase 2: Extract answer key (item_number → letter) from last 40% of document
- Phase 3: Match questions to answers by item number, resolve letter → full option text
- Unmatched questions go to skipped list with reason shown in Jobs page
- Standard inline format (PREP 2012) unchanged

Updated extraction prompts:
- item_number field added to all extractions for cross-referencing
- Image content rule: "Item CXXXB" figure references must NOT be treated as new questions
- Recognises both "Correct Answer: X" and "Preferred Response: X"
- ANSWER_KEY_PROMPT: dedicated prompt for extracting answer key tables

Quiz navigation scroll:
- Clicking Next, Previous, or question number now scrolls the question card
  into view (smooth scroll to start of question-card div)

Code: extract_questions_no_answers(), extract_answer_key(), _call_model() added to ai_service.py

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
2026-04-01 03:22:26 +02:00

282 lines
12 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

"""Async quiz extraction task with step-by-step progress reporting via Redis."""
import json
import logging
import time
from app.tasks import celery_app
from app.database import SessionLocal
logger = logging.getLogger(__name__)
EXPIRE_SECONDS = 3600 # keep progress for 1 hour
def _redis():
import redis
from app.config import settings
return redis.from_url(settings.REDIS_URL, decode_responses=True)
def _push_step(r, job_id: str, step: str, message: str):
key = f"extraction:steps:{job_id}"
entry = json.dumps({"step": step, "message": message, "ts": time.time()})
r.rpush(key, entry)
r.expire(key, EXPIRE_SECONDS)
@celery_app.task(name="extract_quiz", bind=True)
def extract_quiz(
self,
job_id: str,
user_id: int,
section_id: int,
title: str,
mode: str,
time_limit_minutes: int | None,
model_id: str | None,
question_category_id: int | None,
):
"""Background quiz extraction task with live progress reporting."""
r = _redis()
r.set(f"extraction:status:{job_id}", "running", ex=EXPIRE_SECONDS)
# Ensure user job index exists (in case set before task ran)
r.lpush(f"extraction:user_jobs:{user_id}", job_id)
r.expire(f"extraction:user_jobs:{user_id}", 86400)
db = SessionLocal()
try:
from app.models.section import Section
from app.models.pdf_document import PDFDocument
from app.services import ai_service, vector_service, pdf_service, embedding_service
from app.models.quiz import Quiz
from app.models.question import Question
from app.models.quiz_question_link import QuizQuestionLink
from app.config import settings
import os
_push_step(r, job_id, "start", "Starting extraction…")
section = db.query(Section).filter(Section.id == section_id).first()
if not section:
raise ValueError("Section not found")
document = db.query(PDFDocument).filter(PDFDocument.id == section.document_id).first()
if not document:
raise ValueError("Document not found")
total_pages = section.end_page - section.start_page + 1
_push_step(r, job_id, "text", f"Loading text from pages {section.start_page}{section.end_page} ({total_pages} pages)…")
# Determine model first (used for chunk logging)
if model_id:
from app.models.ai_model_config import AIModelConfig
config = db.query(AIModelConfig).filter(AIModelConfig.model_id == model_id).first()
api_key = config.api_key if config and config.api_key else None
model_name = config.name if config else model_id
else:
model_id, api_key = ai_service.get_model_for_task(db, "extraction")
model_name = model_id
# For large page ranges, process in chunks of 50 pages to avoid truncation
CHUNK_PAGES = 50
import json as _json
if total_pages <= CHUNK_PAGES:
chunks = [(section.start_page, section.end_page)]
else:
chunks = []
p = section.start_page
while p <= section.end_page:
end = min(p + CHUNK_PAGES - 1, section.end_page)
chunks.append((p, end))
p = end + 1
n_chunks = len(chunks)
if n_chunks > 1:
_push_step(r, job_id, "text", f"Large section: splitting into {n_chunks} chunks of up to {CHUNK_PAGES} pages each.")
# --- Detect end-of-document answer key format (e.g. PREP 2013) ---
last_chunk_content = vector_service.get_pages_text(
document_id=section.document_id,
start_page=max(section.end_page - 40, section.start_page),
end_page=section.end_page,
)
has_end_answer_key = bool(last_chunk_content and (
"Preferred Response:" in last_chunk_content or
"preferred response:" in last_chunk_content.lower()
))
if has_end_answer_key:
_push_step(r, job_id, "ai", "Detected end-of-document answer key format (Preferred Response). Using two-phase extraction.")
all_valid_questions = []
all_skipped = []
if has_end_answer_key:
# === PHASE 1: Extract questions (allow null correct_answer) ===
raw_questions = []
for chunk_idx, (start_p, end_p) in enumerate(chunks, 1):
_push_step(r, job_id, "ai", f"Phase 1 Chunk {chunk_idx}/{n_chunks}: pages {start_p}{end_p} (questions)…")
chunk_content = vector_service.get_pages_text(
document_id=section.document_id, start_page=start_p, end_page=end_p,
)
if not chunk_content:
continue
try:
chunk_qs = ai_service.extract_questions_no_answers(
chunk_content, page_info=f"{start_p}-{end_p}",
page_ref=start_p, model_id=model_id, api_key=api_key,
)
raw_questions.extend(chunk_qs)
_push_step(r, job_id, "ai", f" Pages {start_p}{end_p}: {len(chunk_qs)} questions found. Total: {len(raw_questions)}.")
except Exception as e:
_push_step(r, job_id, "ai", f" Pages {start_p}{end_p} failed: {e}. Continuing…")
# === PHASE 2: Extract answer key from end of document ===
_push_step(r, job_id, "ai", f"Phase 2 Extracting answer key from last pages…")
# Include larger portion for answer key (last 30-40% of doc)
answer_start = max(section.start_page, int(section.end_page * 0.6))
answer_content = vector_service.get_pages_text(
document_id=section.document_id,
start_page=answer_start,
end_page=section.end_page,
)
answer_key = ai_service.extract_answer_key(
answer_content, page_info=f"{answer_start}-{section.end_page}",
model_id=model_id, api_key=api_key,
)
_push_step(r, job_id, "ai", f" Answer key extracted: {len(answer_key)} answers found.")
# === PHASE 3: Match questions to answers ===
_push_step(r, job_id, "ai", "Phase 3 Matching questions to answers…")
for q in raw_questions:
item_num = q.get("item_number")
if not item_num:
# No item number — skip
all_skipped.append(q.get("question_text", "")[:120])
continue
letter = answer_key.get(item_num)
if not letter:
all_skipped.append(q.get("question_text", "")[:120])
continue
# Resolve letter → full option text
options = q.get("options") or []
letter_idx = ord(letter.upper()) - ord("A")
if 0 <= letter_idx < len(options):
q["correct_answer"] = options[letter_idx]
all_valid_questions.append(q)
else:
all_skipped.append(q.get("question_text", "")[:120])
_push_step(r, job_id, "ai", f"Matching complete: {len(all_valid_questions)} matched, {len(all_skipped)} unmatched.")
else:
# === STANDARD: inline correct answer format ===
for chunk_idx, (start_p, end_p) in enumerate(chunks, 1):
if n_chunks > 1:
_push_step(r, job_id, "ai", f"Chunk {chunk_idx}/{n_chunks}: pages {start_p}{end_p}{model_name}")
else:
_push_step(r, job_id, "ai", f"Sending pages {start_p}{end_p} to {model_name}")
chunk_content = vector_service.get_pages_text(
document_id=section.document_id, start_page=start_p, end_page=end_p,
)
if not chunk_content:
_push_step(r, job_id, "ai", f" No text found for pages {start_p}{end_p}, skipping.")
continue
try:
chunk_data = ai_service.extract_questions(
chunk_content, page_info=f"{start_p}-{end_p}",
page_ref=start_p, model_id=model_id, api_key=api_key,
)
chunk_skipped = []
if chunk_data and chunk_data[0].get("skipped"):
chunk_skipped = chunk_data[0].pop("skipped")
chunk_valid = [q for q in chunk_data if q.get("correct_answer")]
all_valid_questions.extend(chunk_valid)
all_skipped.extend(chunk_skipped)
_push_step(r, job_id, "ai", f" Pages {start_p}{end_p}: {len(chunk_valid)} questions extracted{f', {len(chunk_skipped)} skipped' if chunk_skipped else ''}. Total so far: {len(all_valid_questions)}.")
except Exception as e:
_push_step(r, job_id, "ai", f" Pages {start_p}{end_p} failed: {e}. Continuing…")
valid_questions = all_valid_questions
skipped = all_skipped
_push_step(r, job_id, "ai", f"Extraction complete: {len(valid_questions)} total valid questions{f', {len(skipped)} skipped' if skipped else ''}.")
if not valid_questions:
raise ValueError("No valid questions extracted. The AI could not find questions with correct answers in this page range.")
# Extract images
_push_step(r, job_id, "images", "Extracting question images…")
file_path = os.path.join(settings.UPLOAD_DIR, document.filename)
page_images = {}
if os.path.exists(file_path):
try:
page_images = pdf_service.extract_all_images(
file_path, document.id, section.start_page, section.end_page
)
except Exception as e:
_push_step(r, job_id, "images", f"Image extraction skipped: {e}")
# Create quiz
quiz = Quiz(
section_id=section_id,
user_id=user_id,
title=title,
questions_count=len(valid_questions),
mode=mode,
time_limit_minutes=time_limit_minutes,
skipped_questions=_json.dumps(skipped) if skipped else None,
)
db.add(quiz)
db.flush()
_push_step(r, job_id, "save", f"Saving {len(valid_questions)} questions and generating embeddings…")
for pos, q in enumerate(valid_questions):
page_ref = q.get("page_reference")
image_path = None
if page_ref and page_ref in page_images and page_images[page_ref]:
image_path = page_images[page_ref].pop(0)
if not page_images[page_ref]:
del page_images[page_ref]
question = Question(
source_quiz_id=quiz.id,
question_category_id=question_category_id,
question_text=q["question_text"],
question_type=q["question_type"],
options=q.get("options"),
correct_answer=q["correct_answer"],
explanation=q.get("explanation", ""),
page_reference=page_ref,
image_path=image_path,
)
db.add(question)
db.flush()
db.add(QuizQuestionLink(quiz_id=quiz.id, question_id=question.id, position=pos))
try:
embedding_service.embed_question(question)
except Exception:
pass
db.commit()
db.refresh(quiz)
_push_step(r, job_id, "done", f"Quiz ready! {len(valid_questions)} questions extracted and saved.")
r.set(f"extraction:status:{job_id}", "completed", ex=EXPIRE_SECONDS)
r.set(f"extraction:quiz_id:{job_id}", str(quiz.id), ex=EXPIRE_SECONDS)
return quiz.id
except Exception as e:
logger.exception(f"Quiz extraction failed for job {job_id}")
_push_step(r, job_id, "error", f"Extraction failed: {e}")
r.set(f"extraction:status:{job_id}", "failed", ex=EXPIRE_SECONDS)
r.set(f"extraction:error:{job_id}", str(e)[:500], ex=EXPIRE_SECONDS)
raise
finally:
db.close()