import dlib
import cv2 as cv


class Tracker:
    def __init__(self):
        self.tracker = dlib.correlation_tracker()
        self.is_tracking = False

    def start_tracking(self, img, bbox):
        """Initialize the tracker with the given bounding box."""
        x, y, w, h = bbox
        self.tracker.start_track(img, dlib.rectangle(x, y, x + w, y + h))
        self.is_tracking = True

    def update(self, img):
        """Update the tracker with the new frame."""
        if not self.is_tracking:
            return None

        self.tracker.update(img)
        pos = self.tracker.get_position()
        x1, y1, x2, y2 = int(pos.left()), int(pos.top()), int(pos.right()), int(pos.bottom())

        # Validate the bounding box
        if (x2 - x1) > 0 and (y2 - y1) > 0:
            return (x1, y1, x2 - x1, y2 - y1)  # Valid bounding box
        else:
            self.is_tracking = False  # Stop tracking if the box is invalid
            return None