"""PaddleOCR 本地 OCR（可选依赖）。"""
from __future__ import annotations

import asyncio
from pathlib import Path

from .base import OCRProvider


class PaddleOCRProvider(OCRProvider):
    """通过 PaddleOCR 本地识文。需 pip install paddleocr paddlepaddle。"""

    name = "paddleocr"

    def __init__(self, lang: str = "ch") -> None:
        self.lang = lang
        self._engine = None

    async def recognize(self, image_path: Path) -> str:
        return await asyncio.to_thread(self._sync_recognize, image_path)

    def _sync_recognize(self, image_path: Path) -> str:
        try:
            from paddleocr import PaddleOCR  # type: ignore
        except ImportError as exc:
            raise RuntimeError(
                "未安装 PaddleOCR，请执行: pip install paddleocr paddlepaddle"
            ) from exc

        if self._engine is None:
            self._engine = PaddleOCR(use_angle_cls=True, lang=self.lang, show_log=False)

        result = self._engine.ocr(str(image_path), cls=True)
        lines: list[str] = []
        if result and result[0]:
            for line in result[0]:
                if line and len(line) >= 2:
                    text_part = line[1]
                    if isinstance(text_part, (list, tuple)) and text_part:
                        lines.append(str(text_part[0]))
                    elif isinstance(text_part, str):
                        lines.append(text_part)
        return "\n".join(lines).strip()