from __future__ import annotations
from typing import List

import numpy as np

from core.layout import LayoutBox
from core.post_process import (
    clip_boxes_to_image_bound,
    filter_boxes_by_conf,
    filter_boxes_by_overlaps,
    merge_boxes_list,
)


def predict_img(
    img: np.ndarray,
    model_name: str,
    img_size: int,
    multi_scale: bool,
    **kwargs,
) -> List[LayoutBox]:
    """
    根据模型名称预测布局检测框。模型仅在被调用时加载（以节省GPU资源）。
    """
    if model_name == "ocr-layout":
        from core.detectors.yolov7 import Yolov7Detector

        if not multi_scale:
            return Yolov7Detector.predict(img, img_size, **kwargs)

        scale_factors = [0.5, 0.75, 1.0, 1.25, 1.5]
        img_sizes = [int(img_size * factor) for factor in scale_factors]
        boxes_list = [Yolov7Detector.predict(img, size) for size in img_sizes]
        img_h, img_w = img.shape[:2]
        boxes = merge_boxes_list(
            boxes_list, img_w, img_h, method="nms", iou_threshold=0.55
        )
        return boxes

    elif model_name == "ocr-layout-paddle":
        from core.detectors.paddle_yolo import PaddleYoloDetector

        boxes = PaddleYoloDetector.predict(img, **kwargs)

        # 该模型预测的类型暂时需要重新映射
        # FIXME: 统一类型
        _clazz_remap = {11: 10, 12: 11}
        for b in boxes:
            if b.clazz in _clazz_remap:
                b.clazz = _clazz_remap[b.clazz]

        img_h, img_w = img.shape[:2]
        boxes = clip_boxes_to_image_bound(boxes, img_w, img_h)
        boxes = filter_boxes_by_conf(boxes, conf_threshold=0.1)
        boxes = filter_boxes_by_overlaps(
            boxes, overlaps_iou_threshold=0.8, overlaps_max_count=3
        )
        return boxes
    else:
        raise RuntimeError(f"Invalid model name: {model_name}")