Files
label_ai_service/app/services/qa_service.py
wh 4211e587ee feat(US5+6): QA generation — POST /api/v1/qa/gen-text and /gen-image
- Add qa_models.py with TextQAItem, GenTextQARequest, QAPair, ImageQAItem,
  GenImageQARequest, ImageQAPair, TextQAResponse, ImageQAResponse
- Implement gen_text_qa(): batch-formats triples into a single prompt, calls
  llm.chat(), parses JSON array via extract_json()
- Implement gen_image_qa(): downloads cropped image from source-data bucket,
  base64-encodes inline (data URI), builds multimodal message, calls
  llm.chat_vision(), parses JSON; image_path preserved on ImageQAPair
- Replace qa.py stub with full router: POST /qa/gen-text and /qa/gen-image
  using Depends(get_llm_client) and Depends(get_storage_client)
- 15 new tests (8 service + 7 router), 53/53 total passing
2026-04-10 16:05:49 +08:00

107 lines
3.4 KiB
Python

import base64
from app.clients.llm.base import LLMClient
from app.clients.storage.base import StorageClient
from app.core.config import get_config
from app.core.json_utils import extract_json
from app.core.logging import get_logger
from app.models.qa_models import (
GenImageQARequest,
GenTextQARequest,
ImageQAPair,
ImageQAResponse,
QAPair,
TextQAResponse,
)
logger = get_logger(__name__)
_DEFAULT_TEXT_PROMPT = (
"请根据以下知识三元组生成问答对,以 JSON 数组格式返回,每条包含 question 和 answer 字段。\n\n"
"三元组列表:\n{triples_text}"
)
_DEFAULT_IMAGE_PROMPT = (
"请根据图片内容和以下四元组信息生成问答对,以 JSON 数组格式返回,每条包含 question 和 answer 字段。"
)
async def gen_text_qa(req: GenTextQARequest, llm: LLMClient) -> TextQAResponse:
cfg = get_config()
model = req.model or cfg["models"]["default_text"]
# Format all triples + source snippets into a single batch prompt
triple_lines: list[str] = []
for item in req.items:
triple_lines.append(
f"({item.subject}, {item.predicate}, {item.object}) — 来源: {item.source_snippet}"
)
triples_text = "\n".join(triple_lines)
prompt_template = req.prompt_template or _DEFAULT_TEXT_PROMPT
if "{triples_text}" in prompt_template:
prompt = prompt_template.format(triples_text=triples_text)
else:
prompt = prompt_template + "\n\n" + triples_text
messages = [{"role": "user", "content": prompt}]
raw = await llm.chat(model, messages)
logger.info("gen_text_qa", extra={"items": len(req.items), "model": model})
items_raw = extract_json(raw)
pairs = [QAPair(question=item["question"], answer=item["answer"]) for item in items_raw]
return TextQAResponse(pairs=pairs)
async def gen_image_qa(
req: GenImageQARequest,
llm: LLMClient,
storage: StorageClient,
) -> ImageQAResponse:
cfg = get_config()
bucket = cfg["storage"]["buckets"]["source_data"]
model = req.model or cfg["models"]["default_vision"]
prompt = req.prompt_template or _DEFAULT_IMAGE_PROMPT
pairs: list[ImageQAPair] = []
for item in req.items:
# Download cropped image bytes from storage
image_bytes = await storage.download_bytes(bucket, item.cropped_image_path)
# Base64 encode inline for multimodal message
b64 = base64.b64encode(image_bytes).decode()
image_data_url = f"data:image/jpeg;base64,{b64}"
# Build quad info text
quad_text = f"{item.subject}{item.predicate}{item.object}"
if item.qualifier:
quad_text += f" ({item.qualifier})"
messages = [
{
"role": "user",
"content": [
{"type": "image_url", "image_url": {"url": image_data_url}},
{"type": "text", "text": f"{prompt}\n\n{quad_text}"},
],
}
]
raw = await llm.chat_vision(model, messages)
logger.info("gen_image_qa", extra={"path": item.cropped_image_path, "model": model})
items_raw = extract_json(raw)
for qa in items_raw:
pairs.append(
ImageQAPair(
question=qa["question"],
answer=qa["answer"],
image_path=item.cropped_image_path,
)
)
return ImageQAResponse(pairs=pairs)