from pathlib import Path

import os

from PIL import Image

from app.core.config import settings

# 无图形界面服务器：避免 OpenCV/Paddle 依赖 X11
os.environ.setdefault("OPENCV_IO_ENABLE_OPENEXR", "0")

_ocr_engine = None


def get_ocr_engine():
    global _ocr_engine
    if _ocr_engine is None:
        from paddleocr import PaddleOCR

        _ocr_engine = PaddleOCR(use_angle_cls=True, lang="ch", show_log=False)
    return _ocr_engine


def _bbox_from_box(box: list) -> list[float]:
    xs = [float(p[0]) for p in box]
    ys = [float(p[1]) for p in box]
    return [min(xs), min(ys), max(xs), max(ys)]


def run_ocr_with_regions(image_path: str) -> dict:
    """Return OCR text plus line-level bounding boxes for annotation."""
    engine = get_ocr_engine()
    result = engine.ocr(image_path, cls=True)
    lines: list[dict] = []
    if result and result[0]:
        for item in result[0]:
            if not item or len(item) < 2:
                continue
            box, rec = item[0], item[1]
            text = rec[0] if rec else ""
            conf = float(rec[1]) if rec and len(rec) > 1 else 0.0
            if not text:
                continue
            lines.append(
                {
                    "text": text,
                    "confidence": conf,
                    "box": box,
                    "bbox": _bbox_from_box(box),
                }
            )

    width, height = 0, 0
    try:
        with Image.open(image_path) as img:
            width, height = img.size
    except OSError:
        pass

    return {
        "text": "\n".join(line["text"] for line in lines),
        "lines": lines,
        "width": width,
        "height": height,
    }


def run_ocr(image_path: str) -> str:
    return run_ocr_with_regions(image_path)["text"]


def save_upload_file(user_id: str, question_id: str, filename: str, content: bytes) -> str:
    ext = Path(filename).suffix.lower() or ".jpg"
    if ext not in {".jpg", ".jpeg", ".png", ".webp"}:
        ext = ".jpg"
    user_dir = Path(settings.UPLOAD_DIR) / user_id
    user_dir.mkdir(parents=True, exist_ok=True)
    rel_path = f"{user_id}/{question_id}{ext}"
    full_path = Path(settings.UPLOAD_DIR) / rel_path
    full_path.write_bytes(content)
    return rel_path


def annotated_rel_path(original_rel: str) -> str:
    p = Path(original_rel)
    return str(p.parent / f"{p.stem}_marked.jpg")