import cv2
import numpy as np
import onnxruntime

from watermark_verify.tools import parse_qrcode_label_file


def preproc(img, input_size, swap=(2, 0, 1)):
    if len(img.shape) == 3:
        padded_img = np.ones((input_size[0], input_size[1], 3), dtype=np.uint8) * 114
    else:
        padded_img = np.ones(input_size, dtype=np.uint8) * 114

    r = min(input_size[0] / img.shape[0], input_size[1] / img.shape[1])
    resized_img = cv2.resize(
        img,
        (int(img.shape[1] * r), int(img.shape[0] * r)),
        interpolation=cv2.INTER_LINEAR,
    ).astype(np.uint8)
    padded_img[: int(img.shape[0] * r), : int(img.shape[1] * r)] = resized_img

    padded_img = padded_img.transpose(swap)
    padded_img = np.ascontiguousarray(padded_img, dtype=np.float32)
    return padded_img, r


def demo_postprocess(outputs, img_size, p6=False):
    grids = []
    expanded_strides = []
    strides = [8, 16, 32] if not p6 else [8, 16, 32, 64]

    hsizes = [img_size[0] // stride for stride in strides]
    wsizes = [img_size[1] // stride for stride in strides]

    for hsize, wsize, stride in zip(hsizes, wsizes, strides):
        xv, yv = np.meshgrid(np.arange(wsize), np.arange(hsize))
        grid = np.stack((xv, yv), 2).reshape(1, -1, 2)
        grids.append(grid)
        shape = grid.shape[:2]
        expanded_strides.append(np.full((*shape, 1), stride))

    grids = np.concatenate(grids, 1)
    expanded_strides = np.concatenate(expanded_strides, 1)
    outputs[..., :2] = (outputs[..., :2] + grids) * expanded_strides
    outputs[..., 2:4] = np.exp(outputs[..., 2:4]) * expanded_strides

    return outputs


def nms(boxes, scores, nms_thr):
    """Single class NMS implemented in Numpy."""
    x1 = boxes[:, 0]
    y1 = boxes[:, 1]
    x2 = boxes[:, 2]
    y2 = boxes[:, 3]

    areas = (x2 - x1 + 1) * (y2 - y1 + 1)
    order = scores.argsort()[::-1]

    keep = []
    while order.size > 0:
        i = order[0]
        keep.append(i)
        xx1 = np.maximum(x1[i], x1[order[1:]])
        yy1 = np.maximum(y1[i], y1[order[1:]])
        xx2 = np.minimum(x2[i], x2[order[1:]])
        yy2 = np.minimum(y2[i], y2[order[1:]])

        w = np.maximum(0.0, xx2 - xx1 + 1)
        h = np.maximum(0.0, yy2 - yy1 + 1)
        inter = w * h
        ovr = inter / (areas[i] + areas[order[1:]] - inter)

        inds = np.where(ovr <= nms_thr)[0]
        order = order[inds + 1]

    return keep


def multiclass_nms_class_agnostic(boxes, scores, nms_thr, score_thr):
    """Multiclass NMS implemented in Numpy. Class-agnostic version."""
    cls_inds = scores.argmax(1)
    cls_scores = scores[np.arange(len(cls_inds)), cls_inds]

    valid_score_mask = cls_scores > score_thr
    if valid_score_mask.sum() == 0:
        return None
    valid_scores = cls_scores[valid_score_mask]
    valid_boxes = boxes[valid_score_mask]
    valid_cls_inds = cls_inds[valid_score_mask]
    keep = nms(valid_boxes, valid_scores, nms_thr)
    if keep:
        dets = np.concatenate(
            [valid_boxes[keep], valid_scores[keep, None], valid_cls_inds[keep, None]], 1
        )
    return dets


def multiclass_nms_class_aware(boxes, scores, nms_thr, score_thr):
    """Multiclass NMS implemented in Numpy. Class-aware version."""
    final_dets = []
    num_classes = scores.shape[1]
    for cls_ind in range(num_classes):
        cls_scores = scores[:, cls_ind]
        valid_score_mask = cls_scores > score_thr
        if valid_score_mask.sum() == 0:
            continue
        else:
            valid_scores = cls_scores[valid_score_mask]
            valid_boxes = boxes[valid_score_mask]
            keep = nms(valid_boxes, valid_scores, nms_thr)
            if len(keep) > 0:
                cls_inds = np.ones((len(keep), 1)) * cls_ind
                dets = np.concatenate(
                    [valid_boxes[keep], valid_scores[keep, None], cls_inds], 1
                )
                final_dets.append(dets)
    if len(final_dets) == 0:
        return None
    return np.concatenate(final_dets, 0)


def multiclass_nms(boxes, scores, nms_thr, score_thr, class_agnostic=True):
    """Multiclass NMS implemented in Numpy"""
    if class_agnostic:
        nms_method = multiclass_nms_class_agnostic
    else:
        nms_method = multiclass_nms_class_aware
    return nms_method(boxes, scores, nms_thr, score_thr)


def compute_ciou(box1, box2):
    """计算CIoU，假设box格式为[x1, y1, x2, y2]"""
    x1, y1, x2, y2 = box1
    x1g, y1g, x2g, y2g = box2

    # 求交集面积
    xi1, yi1 = max(x1, x1g), max(y1, y1g)
    xi2, yi2 = min(x2, x2g), min(y2, y2g)
    inter_area = max(0, xi2 - xi1) * max(0, yi2 - yi1)

    # 求各自面积
    box_area = (x2 - x1) * (y2 - y1)
    boxg_area = (x2g - x1g) * (y2g - y1g)

    # 求并集面积
    union_area = box_area + boxg_area - inter_area

    # 求IoU
    iou = inter_area / union_area

    # 求CIoU额外项
    cw = max(x2, x2g) - min(x1, x1g)
    ch = max(y2, y2g) - min(y1, y1g)
    c2 = cw ** 2 + ch ** 2
    rho2 = ((x1 + x2 - x1g - x2g) ** 2 + (y1 + y2 - y1g - y2g) ** 2) / 4

    ciou = iou - (rho2 / c2)
    return ciou


def detect_watermark(dets, watermark_boxes, threshold=0.5):
    for box, score, cls in zip(dets[:, :4], dets[:, 4], dets[:, 5]):
        for wm_box in watermark_boxes:
            wm_box_coords = wm_box[:4]
            wm_cls = wm_box[4]
            if cls == wm_cls:
                ciou = compute_ciou(box, wm_box_coords)
                if ciou > threshold:
                    return True
    return False


def predict_and_detect(image_path, model_file, watermark_txt, input_shape) -> bool:
    """
    使用指定onnx文件进行预测并进行黑盒水印检测
    :param image_path: 输入图像路径
    :param model_file: 模型文件路径
    :param watermark_txt: 水印标签文件路径
    :param input_shape: 模型输入图像大小，tuple
    :return:
    """
    origin_img = cv2.imread(image_path)
    img, ratio = preproc(origin_img, input_shape)
    height, width, channels = origin_img.shape
    watermark_boxes = parse_qrcode_label_file.load_watermark_info(watermark_txt, width, height)

    session = onnxruntime.InferenceSession(model_file)

    ort_inputs = {session.get_inputs()[0].name: img[None, :, :, :]}
    output = session.run(None, ort_inputs)
    predictions = demo_postprocess(output[0], input_shape)[0]

    boxes = predictions[:, :4]
    scores = predictions[:, 4:5] * predictions[:, 5:]

    boxes_xyxy = np.ones_like(boxes)
    boxes_xyxy[:, 0] = boxes[:, 0] - boxes[:, 2] / 2.
    boxes_xyxy[:, 1] = boxes[:, 1] - boxes[:, 3] / 2.
    boxes_xyxy[:, 2] = boxes[:, 0] + boxes[:, 2] / 2.
    boxes_xyxy[:, 3] = boxes[:, 1] + boxes[:, 3] / 2.
    boxes_xyxy /= ratio
    dets = multiclass_nms(boxes_xyxy, scores, nms_thr=0.45, score_thr=0.1)
    if dets is not None:
        detect_result = detect_watermark(dets, watermark_boxes.get(image_path, []))
        return detect_result
    else:
        return False