import cv2
import numpy as np
import random
from config_files.yolo_config import CLASS_NAME, CLASS_NUM
from typing import List, Tuple

class Inference:
    def __init__(self, onnx_model_path, model_input_shape, classes_txt_file, run_with_cuda):
        self.model_path = onnx_model_path
        self.model_shape = model_input_shape
        self.classes_path = classes_txt_file
        self.cuda_enabled = run_with_cuda
        self.letter_box_for_square = True
        self.model_score_threshold = 0.3
        self.model_nms_threshold = 0.5
        self.classes = []

        self.load_onnx_network()
        self.load_classes_from_file()

    def sigmoid(self, x):
        return 1 / (1 + np.exp(-x))

    def run_inference(self, input_image):
        model_input = input_image
        if self.letter_box_for_square and self.model_shape[0] == self.model_shape[1]:
            model_input = self.format_to_square(model_input)

        blob = cv2.dnn.blobFromImage(model_input, 1.0 / 255.0, self.model_shape, (0, 0, 0), True, False)
        self.net.setInput(blob)

        outputs = self.net.forward(self.net.getUnconnectedOutLayersNames())
        outputs_bbox = outputs[0]
        outputs_mask = outputs[1]

        detections = self.process_detections(outputs_bbox, model_input)
        mask_maps = self.process_mask_output(detections, outputs_mask, model_input.shape)

        return detections, mask_maps

    def process_detections(self, outputs_bbox, model_input):
        # Assuming outputs_bbox is already in the (x, y, w, h, confidence, class_probs...) format
        x_factor = model_input.shape[1] / self.model_shape[0]
        y_factor = model_input.shape[0] / self.model_shape[1]

        class_ids = []
        confidences = []
        mask_coefficients = []
        boxes = []

        for detection in outputs_bbox[0].T:
            # This segmentation model uses yolact architecture to predict mask
            # the output tensor dimension for yolo-v8-seg is B x [X, Y, W, H, C1, C2, ..., P1, ...,P32] * 8400
            # where C{n} are confidence score for each class
            # and P{n} are coefficient for each proto masks. (32 by default)
            scores_classification = detection[4:4+CLASS_NUM]
            scores_segmentation = detection[4+CLASS_NUM:]
            class_id = np.argmax(scores_classification, axis=0)
            confidence = scores_classification[class_id]

            thres = self.model_score_threshold
            w_thres = 40
            h_thres = 40

            x, y, w, h = detection[:4]
            # if bboxes are too small, it just skips, and it is not a bad idea since we do not need to detect small areas
            if w < w_thres or h < h_thres:
                continue

            if confidence > thres:

                left = int((x - 0.5 * w) * x_factor)
                top = int((y - 0.5 * h) * y_factor)
                width = int(w * x_factor)
                height = int(h * y_factor)

                boxes.append([left, top, width, height])
                confidences.append(float(confidence))
                mask_coefficients.append(scores_segmentation)
                class_ids.append(class_id)
        confidences = (confidences)
        indices = cv2.dnn.NMSBoxes(boxes, confidences, self.model_score_threshold, self.model_nms_threshold)

        detections = []
        for i in indices:
            idx = i
            result = {
                'class_id': class_ids[i],
                'confidence': confidences[i],
                'mask_coefficients': np.array(mask_coefficients[i]),
                'box': boxes[idx],
                'class_name': self.classes[class_ids[i]],
                'color': (random.randint(100, 255), random.randint(100, 255), random.randint(100, 255))
            }
            detections.append(result)

        return detections

    def process_mask_output(self, detections, proto_masks, image_shape):
        if not detections:
            return []

        batch_size, num_protos, proto_height, proto_width = proto_masks.shape
        full_masks = np.zeros((len(detections), image_shape[0], image_shape[1]), dtype=np.float32)

        for idx, det in enumerate(detections):
            box = det['box']

            x1, y1, w, h = self.adjust_box_coordinates(box, (image_shape[0], image_shape[1]))

            if w <=1 or h <= 1:
                continue

            # Get the corresponding mask coefficients for this detection
            coeffs = det["mask_coefficients"]

            # Compute the linear combination of proto masks
            # for now, plural batch operation is not supported, and this is the point where you should start.
            # instead of hardcoded proto_masks[0], do some iterative operation.
            mask = np.tensordot(coeffs, proto_masks[0], axes=[0, 0])  # Dot product along the number of prototypes

            # Resize mask to the bounding box size, using sigmoid to normalize
            resized_mask = cv2.resize(mask, (w, h))
            resized_mask = self.sigmoid(resized_mask)

            # Threshold to create a binary mask
            final_mask = (resized_mask > 0.5).astype(np.uint8)

            # Place the mask in the corresponding location on a full-sized mask image_binary
            full_mask = np.zeros((image_shape[0], image_shape[1]), dtype=np.uint8)
            # print("---------")
            # print(f"x1 : {x1}, y1 : {y1}, w: {w}, h: {h}")
            # print(f"x2: {x2}, y2 : {y2}")
            # print(final_mask.shape)
            # print(full_mask[y1:y2, x1:x2].shape)
            full_mask[y1:y1+h, x1:x1+w] = final_mask

            # Combine the mask with the masks of other detections
            full_masks[idx] = full_mask


        all_mask = full_masks.sum(axis=0)
        all_mask = np.clip(all_mask, 0, 1)
        # Append a dimension so that cv2 can understand ```all_mask``` argument as an image.
        # This is because for this particular application, there is only single class ```water_body```
        # However, if that is not the case, you must modify this part.
        all_mask = all_mask.reshape((image_shape[0], image_shape[1], 1))
        return all_mask.astype(np.uint8)

    def adjust_box_coordinates(self, box: List[int], image_shape: Tuple[int, int]) -> Tuple[int, int, int, int]:
        """
        Adjusts bounding box coordinates to ensure they lie within image boundaries.
        """
        x1, y1, w, h = box
        x2, y2 = x1 + w, y1 + h

        # Clamp coordinates to image boundaries
        x1 = max(0, x1)
        y1 = max(0, y1)
        x2 = min(image_shape[1], x2)
        y2 = min(image_shape[0], y2)

        # Recalculate width and height
        w = x2 - x1
        h = y2 - y1

        return x1, y1, w, h


    def load_classes_from_file(self):
        with open(self.classes_path, 'r') as f:
            self.classes = f.read().strip().split('\n')

    def load_onnx_network(self):
        self.net = cv2.dnn.readNetFromONNX(self.model_path)
        if self.cuda_enabled:
            print("\nRunning on CUDA")
            self.net.setPreferableBackend(cv2.dnn.DNN_BACKEND_CUDA)
            self.net.setPreferableTarget(cv2.dnn.DNN_TARGET_CUDA)
        else:
            print("\nRunning on CPU")
            self.net.setPreferableBackend(cv2.dnn.DNN_BACKEND_OPENCV)
            self.net.setPreferableTarget(cv2.dnn.DNN_TARGET_CPU)

    def format_to_square(self, source):
        col, row = source.shape[1], source.shape[0]
        max_side = max(col, row)
        result = np.zeros((max_side, max_side, 3), dtype=np.uint8)
        result[0:row, 0:col] = source
        return result

def overlay_mask(image, mask, color=(0, 255, 0), alpha=0.5):
    """
    Overlays a mask onto an image_binary using a specified color and transparency level.

    Parameters:
        image (np.ndarray): The original image_binary.
        mask (np.ndarray): The mask to overlay. Must be the same size as the image_binary.
        color (tuple): The color for the mask overlay in BGR format (default is green).
        alpha (float): Transparency factor for the mask; 0 is fully transparent, 1 is opaque.

    Returns:
        np.ndarray: The image_binary with the overlay.
    """
    assert alpha <= 1 and 0 <= alpha, (f"Error! invalid alpha value, it must be float, inbetween including 0 to 1, "
                                       f"\n given alpha : {alpha}")

    # Ensure the mask is a binary mask
    mask = (mask > 0).astype(np.uint8)  # Convert mask to binary if not already

    # Create an overlay with the same size as the image_binary but only using the mask area
    overlay = np.zeros_like(image, dtype=np.uint8)
    overlay[mask == 1] = color

    # Blend the overlay with the image_binary using the alpha factor
    return cv2.addWeighted(src1=overlay, alpha=alpha, src2=image, beta=1 - alpha, gamma=0)


def test():
    import time

    # Path to your ONNX model and classes text file
    model_path = 'yoloseg/weight/best.onnx'
    classes_txt_file = 'config_files/yolo_config.txt'
    image_path = 'yoloseg/img3.jpg'

    model_input_shape = (640, 640)
    inference_engine = Inference(
        onnx_model_path=model_path,
        model_input_shape=model_input_shape,
        classes_txt_file=classes_txt_file,
        run_with_cuda=True
    )

    # Load an image_binary
    img = cv2.imread(image_path)
    if img is None:
        print("Error loading image_binary")
        return
    img = cv2.resize(img, model_input_shape)
    # Run inference
    t1 = time.time()
    detections, mask_maps = inference_engine.run_inference(img)
    t2 = time.time()

    print(t2-t1)

    # Display results
    for detection in detections:
        x, y, w, h = detection['box']
        class_name = detection['class_name']
        confidence = detection['confidence']
        cv2.rectangle(img, (x, y), (x+w, y+h), detection['color'], 2)
        label = f"{class_name}: {confidence:.2f}"
        cv2.putText(img, label, (x, y - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, detection['color'], 2)

    # Show the image_binary
    # cv2.imshow('Detections', img)
    # cv2.waitKey(0)
    # cv2.destroyAllWindows()

    # If you also want to display segmentation maps, you would need additional handling here
    # Example for displaying first mask if available:
    if mask_maps is not None:

        seg_image = overlay_mask(img, mask_maps[0], color=(0, 255, 0), alpha=0.3)
        cv2.imshow("segmentation", seg_image)
        cv2.waitKey(0)
        cv2.destroyAllWindows()

# def test2():
#     import time
#     import glob
#
#     # Path to your ONNX model and classes text file
#     model_path = 'yoloseg/weight/best.onnx'
#     classes_txt_file = 'config_files/yolo_config.txt'
#
#     model_input_shape = (640, 640)
#     inference_engine = Inference(
#         onnx_model_path=model_path,
#         model_input_shape=model_input_shape,
#         classes_txt_file=classes_txt_file,
#         run_with_cuda=True
#     )
#
#     image_dir = glob.glob("/home/juni/사진/sample_data/ex1/*.png")
#
#     for iteration, image_path in enumerate(image_dir):
#         img = cv2.imread(image_path)
#         if img is None:
#             print("Error loading image_binary")
#             return
#         img = cv2.resize(img, model_input_shape)
#         # Run inference
#         t1 = time.time()
#         detections, mask_maps = inference_engine.run_inference(img)
#         t2 = time.time()
#
#         print(t2-t1)
#
#         # Display results
#         # for detection in detections:
#         #     x, y, w, h = detection['box']
#         #     class_name = detection['class_name']
#         #     confidence = detection['confidence']
#         #     cv2.rectangle(img, (x, y), (x+w, y+h), detection['color'], 2)
#         #     label = f"{class_name}: {confidence:.2f}"
#         #     cv2.putText(img, label, (x, y - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, detection['color'], 2)
#         #
#         if len(mask_maps) > 0 :
#             seg_image = overlay_mask(img, mask_maps[0], color=(0, 255, 0), alpha=0.3)
#             cv2.imwrite(f"result/{iteration}.png", seg_image)


if __name__ == "__main__":
    pass
    # test2()