import os
import cv2
import argparse
import numpy as np
from datetime import datetime

# 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

# Global variables for the last mouse position
last_x, last_y = 0, 0
img, calibrated_img = None, None


# Function to get the frame index from the filename
def get_frame_index(filename):
    return os.path.splitext(os.path.basename(filename))[0][-5:]


# Function to modify the numeric part of the filename
def modify_filename(filename, frame_increment=1):
    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) < 5 or not basename_no_ext[-5:].isdigit():
        raise ValueError("Filename does not end with five digits.")
    
    num_part = basename_no_ext[-5:]
    num = int(num_part) + frame_increment

    # Handle rollover
    num = num % 100000  # Modulo 100000 for 5 digits

    new_name = f"{basename_no_ext[:-5]}{num:05d}{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


# Function to display the image and pixel values along with the frame index
def show_pixel_values(image_path):
    global img, calibrated_img, last_x, last_y

    def mouse_event(event, x, y, flags, param):
        global last_x, last_y
        if event == cv2.EVENT_MOUSEMOVE:
            last_x, last_y = x, y
            update_display(x, y)

    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

    calibrated_img = calibrate(img)  # Calibrate the image for display

    cv2.namedWindow('Image')
    cv2.setMouseCallback('Image', mouse_event)
    update_display(last_x, last_y)  # Initial display update
    return True

# Function to update the display with pixel values
def update_display(x, y):
    global img, calibrated_img
    original_pixel_value = img[y, x]
    calibrated_pixel_value = calibrated_img[y, x]
    text_original = f'Original: {original_pixel_value}, Loc: ({x},{y})'
    text_calibrated = f'Calibrated: {calibrated_pixel_value}'
    img_text = img.copy()
    frame_index = get_frame_index(img_path)
    cv2.putText(img_text, f'Frame: {frame_index}', (10, img_text.shape[0] - 20), cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255, 255, 255), 1, cv2.LINE_AA)
    cv2.putText(img_text, text_original, (5, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255, 255, 255), 1, cv2.LINE_AA)
    cv2.putText(img_text, text_calibrated+"c", (5, 50), cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255, 255, 255), 1, cv2.LINE_AA)
    cv2.imshow('Image', img_text)
    return img_text # Return the image with text for saving

def save_frame(img_text):
    current_time = datetime.now().strftime("%Y%m%d_%H%M%S")
    save_path = f"frame_{current_time}.png"
    cv2.imwrite(save_path, img_text)
    print(f"Frame saved as {save_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 in [91, 93, ord('{'), ord('}')]:  # Keys for frame navigation
        if key == 91:  # '[' key
            img_path = modify_filename(img_path, frame_increment=-1)
        elif key == 93:  # ']' key
            img_path = modify_filename(img_path, frame_increment=1)
        elif key == ord('{'):  # Shift + '['
            img_path = modify_filename(img_path, frame_increment=-50)
        elif key == ord('}'):  # Shift + ']'
            img_path = modify_filename(img_path, frame_increment=50)
        
        if not show_pixel_values(img_path):
            break  # Exit if the new image cannot be loaded
        else:
            update_display(last_x, last_y)  # Update display with last known mouse position

    elif key == ord('s'):  # 's' key for saving
        # Update the display to get the latest overlay and save it
        img_text_with_overlays = update_display(last_x, last_y)
        save_frame(img_text_with_overlays)
        continue  # Skip the frame reload if saving

cv2.destroyAllWindows()