Files
odoo-ai/agent_service/tools/receipt_parser.py
Carlos Garcia ec6b41943f fix: vision OCR JSON failures — add format='json' and repair fallback
Three receipts per batch were failing with JSONDecodeError (e.g.
"Expecting ':' delimiter: line 1 column 90") because activeblue-chat
(llama3.2-vision) occasionally outputs near-JSON with trailing commas,
single-quoted strings, or unquoted keys.

Two-layer fix:
1. Add format='json' to the Ollama chat call — Ollama JSON mode forces
   syntactically valid output at the sampler level, eliminating most
   structural errors.
2. Add _repair_json() fallback that runs on any remaining JSONDecodeError:
   strips trailing commas, converts single→double quotes, and quotes
   unquoted keys. If repair succeeds, the result is re-serialised as
   canonical JSON before being returned.

Also re-serialise with json.dumps() on success so the fast path in
_parse_receipt_text always receives clean, canonical JSON regardless of
whitespace or key ordering in the model's original output.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-20 22:24:50 -04:00

286 lines
11 KiB
Python

from __future__ import annotations
import base64
import hashlib
import io
import logging
import re
import zipfile
from pathlib import Path
logger = logging.getLogger(__name__)
# Extract YYYYMMDD from filenames like 20260509_180857.jpg
_DATE_PATTERN = re.compile(r'(\d{4})(\d{2})(\d{2})_\d{6}')
_MIME = {
'.jpg': 'image/jpeg', '.jpeg': 'image/jpeg',
'.png': 'image/png', '.gif': 'image/gif',
'.bmp': 'image/bmp', '.tiff': 'image/tiff', '.tif': 'image/tiff',
'.webp': 'image/webp', '.pdf': 'application/pdf',
'.html': 'text/html', '.htm': 'text/html',
'.txt': 'text/plain', '.zip': 'application/zip',
}
_IMAGE_EXTS = {'.jpg', '.jpeg', '.png', '.gif', '.bmp', '.tiff', '.tif', '.webp'}
def parse_upload(filename: str, data: bytes) -> list[dict]:
"""
Parse one uploaded file into a list of receipt dicts.
ZIP files are recursively unpacked; all other types return a single entry.
Each dict: {filename, text, b64, mimetype}
"""
ext = Path(filename).suffix.lower()
if ext == '.zip':
return _extract_zip(filename, data)
b64 = base64.b64encode(data).decode()
mimetype = _MIME.get(ext, 'application/octet-stream')
sha256 = hashlib.sha256(data).hexdigest()
# Extract date from timestamp-style filenames (e.g. 20260509_180857.jpg)
date_from_name = None
m = _DATE_PATTERN.search(filename)
if m:
date_from_name = f'{m.group(1)}-{m.group(2)}-{m.group(3)}'
if ext in _IMAGE_EXTS:
text = _ocr_image(data, filename)
elif ext == '.pdf':
text = _extract_pdf(data, filename)
elif ext in ('.html', '.htm'):
text = _extract_html(data, filename)
elif ext == '.txt':
text = data.decode('utf-8', errors='replace')
else:
try:
text = data.decode('utf-8', errors='replace')
except Exception:
text = f'[Binary file: {filename}]'
return [{'filename': filename, 'text': text, 'b64': b64, 'mimetype': mimetype,
'sha256': sha256, 'date_from_name': date_from_name}]
def _extract_zip(zip_filename: str, data: bytes) -> list[dict]:
results = []
try:
with zipfile.ZipFile(io.BytesIO(data)) as zf:
for member in zf.namelist():
if member.endswith('/'):
continue
try:
member_data = zf.read(member)
results.extend(parse_upload(Path(member).name, member_data))
except Exception as exc:
logger.warning('receipt_parser: zip member %s failed: %s', member, exc)
except Exception as exc:
logger.error('receipt_parser: zip %s failed: %s', zip_filename, exc)
return results
def _ocr_image(data: bytes, filename: str) -> str:
"""Extract text from a receipt image.
Tries vision-model OCR first when VISION_OCR_MODEL is configured,
then falls back to the Tesseract pipeline.
"""
from agent_service.config import get_settings
settings = get_settings()
if settings.vision_ocr_model:
result = _ocr_image_vision(data, filename,
settings.ollama_url,
settings.vision_ocr_model)
if result:
return result
logger.warning('Vision OCR returned empty for %s — falling back to Tesseract', filename)
return _ocr_image_tesseract(data, filename)
def _ocr_image_vision(data: bytes, filename: str, ollama_url: str, model: str) -> str:
"""Use an Ollama vision model to extract receipt data directly as JSON.
Returns a JSON string {vendor, amount, date, time, category} so the
expenses agent can skip the second LLM extraction step entirely.
Returns empty string on any failure so the caller falls back to Tesseract.
"""
import json as _json
import re as _re
def _repair_json(s: str) -> str:
"""Fix the most common LLM JSON formatting mistakes.
Handles:
- trailing commas before } or ] → {"a":1,} becomes {"a":1}
- single-quoted strings → {'a':'b'} becomes {"a":"b"}
- unquoted string keys → {a: "b"} becomes {"a": "b"}
"""
# trailing commas
s = _re.sub(r',\s*([}\]])', r'\1', s)
# single-quoted strings (careful around apostrophes in values)
s = _re.sub(r"'([^']*)'", r'"\1"', s)
# unquoted keys: word characters before a colon
s = _re.sub(r'(?<!["\w])(\w+)\s*:', r'"\1":', s)
return s
try:
import ollama as _ollama
client = _ollama.Client(host=ollama_url)
response = client.chat(
model=model,
format='json', # Ollama JSON mode — forces syntactically valid output
messages=[{
'role': 'user',
'content': (
'You are a receipt data extractor. '
'Read this receipt image and extract the following fields. '
'Copy values EXACTLY as printed — do NOT guess, infer, or '
'invent values you cannot clearly see.\n\n'
'Fields to extract:\n'
'- vendor: the store or restaurant name exactly as printed; '
'empty string if not clearly visible\n'
'- amount: the FINAL total the customer paid; find a line '
'labeled "Total", "Grand Total", "Amount Due", or "Balance Due"; '
'copy the number exactly; do NOT use subtotal, tax, or tip; '
'return 0 if no clearly labeled final total is visible\n'
'- date: transaction date in YYYY-MM-DD format; '
'null if not clearly visible\n'
'- time: transaction time in HH:MM 24-hour format; '
'null if not clearly visible\n'
'- category: one of: meals, fuel, hotel, office, transport, other\n\n'
'Return ONLY a valid JSON object, no commentary, no markdown:\n'
'{"vendor":"...","amount":0.00,"date":"YYYY-MM-DD or null",'
'"time":"HH:MM or null","category":"..."}'
),
'images': [data],
}],
)
if isinstance(response, dict):
raw = (response.get('message', {}).get('content') or '').strip()
else:
raw = (response.message.content or '').strip()
# Must contain a JSON object, not prose
first, last = raw.find('{'), raw.rfind('}')
if first == -1 or last <= first:
logger.warning('Vision OCR %s: model returned prose, falling back to Tesseract',
filename)
return ''
json_str = raw[first:last + 1]
# Parse — on failure attempt common repairs then retry once
try:
parsed = _json.loads(json_str)
except _json.JSONDecodeError as json_err:
repaired = _repair_json(json_str)
try:
parsed = _json.loads(repaired)
logger.debug('Vision OCR %s: JSON repaired successfully', filename)
except _json.JSONDecodeError:
logger.warning('Vision OCR %s: JSON parse failed (%s), falling back',
filename, json_err)
return ''
if 'amount' not in parsed:
logger.warning('Vision OCR %s: JSON missing amount field, falling back', filename)
return ''
logger.debug('Vision OCR %s (%s): extracted JSON ok', filename, model)
# Re-serialise so downstream always gets clean, canonical JSON
return _json.dumps(parsed)
except ImportError:
logger.warning('ollama package not installed — vision OCR unavailable for %s', filename)
return ''
except Exception as exc:
logger.warning('Vision OCR failed for %s: %s', filename, exc)
return ''
def _ocr_image_tesseract(data: bytes, filename: str) -> str:
"""Tesseract-based OCR pipeline (fallback)."""
try:
from PIL import Image, ImageFilter, ImageOps
import pytesseract
img = Image.open(io.BytesIO(data))
# Resize very large images — tesseract is slower and less accurate at
# phone-camera resolution; 1800px wide is plenty for receipt text.
max_w = 1800
if img.width > max_w:
scale = max_w / img.width
img = img.resize((max_w, int(img.height * scale)), Image.LANCZOS)
# Grayscale + adaptive binarisation + sharpen
img = ImageOps.grayscale(img)
img = ImageOps.autocontrast(img)
img = img.point(lambda x: 0 if x < 140 else 255)
img = img.filter(ImageFilter.SHARPEN)
# psm 1 = automatic page segmentation + OSD (handles rotated receipts).
# Fall back to psm 6 if OSD data is missing.
try:
text = pytesseract.image_to_string(img, config='--oem 3 --psm 1').strip()
except Exception:
text = pytesseract.image_to_string(img, config='--oem 3 --psm 6').strip()
logger.debug('Tesseract OCR %s: %d chars', filename, len(text))
return text
except ImportError:
logger.warning('pytesseract/Pillow not installed — OCR unavailable for %s', filename)
return f'[Image: {filename} — install pytesseract+Pillow for OCR]'
except Exception as exc:
logger.warning('Tesseract OCR failed for %s: %s', filename, exc)
return f'[Image: {filename} — OCR failed: {exc}]'
def _extract_pdf(data: bytes, filename: str) -> str:
try:
import pdfplumber
parts = []
with pdfplumber.open(io.BytesIO(data)) as pdf:
for page in pdf.pages:
t = page.extract_text()
if t:
parts.append(t)
return '\n'.join(parts).strip()
except ImportError:
logger.warning('pdfplumber not installed — PDF extraction unavailable for %s', filename)
return f'[PDF: {filename} — install pdfplumber for text extraction]'
except Exception as exc:
logger.warning('PDF extraction failed for %s: %s', filename, exc)
return f'[PDF: {filename} — extraction failed: {exc}]'
def _extract_html(data: bytes, filename: str) -> str:
try:
from html.parser import HTMLParser
class _TextExtractor(HTMLParser):
def __init__(self):
super().__init__()
self._parts: list[str] = []
self._skip = False
def handle_starttag(self, tag, attrs):
if tag in ('script', 'style'):
self._skip = True
def handle_endtag(self, tag):
if tag in ('script', 'style'):
self._skip = False
def handle_data(self, data):
if not self._skip:
s = data.strip()
if s:
self._parts.append(s)
def text(self):
return ' '.join(self._parts)
parser = _TextExtractor()
parser.feed(data.decode('utf-8', errors='replace'))
return parser.text()
except Exception as exc:
logger.warning('HTML extraction failed for %s: %s', filename, exc)
return f'[HTML: {filename} — extraction failed: {exc}]'