import os
import cv2
import argparse
import numpy as np

# Set up the argument parser
parser = argparse.ArgumentParser(description="Visualize image files and display pixel values on hover.")
parser.add_argument('path', help='The path to an image file.')

# Parse the arguments
args = parser.parse_args()
img_path = args.path


def calibrate(x):
    x = x.astype(float)
    x /= 256.0
    #print('{}..{}'.format(x.max(), x.min()))
    ret = ((-1.665884e-08) * x**4.
        + (1.347094e-05) * x**3.
        + (-4.396264e-03) * x**2.
        + (9.506939e-01) * x
        + (-6.353247e+01))
    #print('{}..{}'.format(ret.max(), ret.min()))
    ret = np.where(ret > 0, ret, 0)
    #print('{}..{}'.format(ret.max(), ret.min()))
    ret = ret.astype('b')
    #print('{}..{}'.format(ret.max(), ret.min()))
    return ret


class state:
    calibrate = False


# Function to display the image and pixel values along with the frame index
def show_pixel_values(image_path):
    def mouse_event(event, x, y, flags, param):
        if event == cv2.EVENT_MOUSEMOVE:
            pixel_value = img[y, x]
            text = f'Value: {pixel_value}, Location: ({x},{y})'
            img_text = img.copy()
            # Overlay the frame index
            frame_index = get_frame_index(image_path)
            cv2.putText(img_text, f'Frame: {frame_index}', (10, img_text.shape[0] - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (255, 255, 255), 1, cv2.LINE_AA)
            cv2.putText(img_text, text, (50, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (255, 255, 255), 1, cv2.LINE_AA)
            cv2.imshow('Image', img_text)

    img = cv2.imread(image_path, cv2.IMREAD_UNCHANGED)
    if img is None:
        print(f"Failed to load image at {image_path}. Check the file path and integrity.")
        return False
    if state.calibrate:
        img = calibrate(img)
    cv2.namedWindow('Image')
    cv2.setMouseCallback('Image', mouse_event)
    cv2.imshow('Image', img)
    return True


# Function to get the frame index from the filename
def get_frame_index(filename):
    return os.path.splitext(os.path.basename(filename))[0][-4:]


# Function to modify the numeric part of the filename
def modify_filename(filename, increment=True):
    directory, basename = os.path.split(filename)
    basename_no_ext, ext = os.path.splitext(basename)
    print(f"Modifying filename {basename_no_ext} in directory {directory}.")
    if len(basename_no_ext) < 4 or not basename_no_ext[-4:].isdigit():
        raise ValueError("Filename does not end with five digits.")
    num_part = basename_no_ext[-4:]
    num = int(num_part) + (1 if increment else -1)
    new_name = f"{basename_no_ext[:-4]}{num:04d}{ext}"
    new_path = os.path.join(directory, new_name)
    if not os.path.exists(new_path):
        print(f"No file found at {new_path}.")
        return filename  # Return the original filename if the new file does not exist
    return new_path


# Ensure the provided path is a valid file
if not os.path.isfile(img_path):
    print("The provided path is not a valid file.")
    exit(1)

# Initially display the image
if not show_pixel_values(img_path):
    exit(1)

# Main loop to navigate through images
while True:
    key = cv2.waitKey(0)
    if key == 27:  # ESC key to exit
        break
    elif key == 91:  # '[' key
        img_path = modify_filename(img_path, increment=False)
    elif key == 93:  # ']' key
        img_path = modify_filename(img_path, increment=True)
    elif key == ord('c'):
        state.calibrate = not state.calibrate

    # Show the new image
    if not show_pixel_values(img_path):
        break  # Exit the loop if the new image cannot be loaded

cv2.destroyAllWindows()