"""OCR 编排：Pix2Text 优先，失败/低置信/未部署时降级到多模态 VLM。"""
import logging

from app.config import settings
from app.services.llm.client import LLMClient
from app.services.ocr.base import OcrResult
from app.services.ocr.pix2text_client import Pix2TextClient
from app.services.ocr.vlm_engine import VlmOcrEngine

logger = logging.getLogger(__name__)

# Pix2Text 结果置信度低于此值则降级到 VLM
_CONFIDENCE_THRESHOLD = 0.5


async def run_ocr(image_bytes: bytes, mime: str, llm: LLMClient) -> OcrResult:
    """返回识别结果，engine 字段标明最终使用的引擎。"""
    # 1. 若配置了 Pix2Text 服务且健康，优先用
    if settings.ocr_service_url:
        client = Pix2TextClient(settings.ocr_service_url)
        if await client.healthy():
            try:
                result = await client.recognize(image_bytes, mime)
                if result.markdown.strip() and result.confidence >= _CONFIDENCE_THRESHOLD:
                    return result
                logger.info(
                    "Pix2Text 置信度低(%.2f)或结果为空，降级 VLM", result.confidence
                )
            except Exception as e:  # noqa: BLE001
                logger.warning("Pix2Text 识别失败，降级 VLM：%s", e)
        else:
            logger.info("Pix2Text 服务不健康，降级 VLM")

    # 2. 降级 / 默认：多模态大模型
    return await VlmOcrEngine(llm).recognize(image_bytes, mime)