import os
import cv2
import numpy as np
import tkinter as tk
from tkinter import filedialog
from PIL import Image, ImageTk

OPENED_IMAGE = None

def padding(file_path, border_width):
    image = cv2.imread(file_path)
    if image is None:
        print("Failed to load the image.")
        return
    padded_image = cv2.copyMakeBorder(
        image,
        top=border_width,
        bottom=border_width,
        left=border_width,
        right=border_width,
        borderType=cv2.BORDER_REFLECT
    )
    _cache_image(padded_image, file_path)

def crop(file_path):
    image = cv2.imread(file_path)
    height, width = image.shape[:2]
    # crop 80 px from top & left, 130 px from bottom & right
    x_0 = 80
    x_1 = width - 130
    y_0 = 80
    y_1 = height - 130
    cropped_image = image[y_0:y_1, x_0:x_1]

    _cache_image(cropped_image, file_path)

def resize(file_path):
    width = 200
    height = 200
    image = cv2.imread(file_path)
    resized_image = cv2.resize(image, (width, height))
    _cache_image(resized_image, file_path)


def copy(file_path):
    image = cv2.imread(file_path)

    height, width, channels = image.shape
    emptyPictureArray = np.zeros((height, width, 3), dtype=np.uint8)

    for y in range(height):
        for x in range(width):
            for c in range(channels):
                emptyPictureArray[y, x, c] = image[y, x, c]
    _cache_image(emptyPictureArray, file_path)


def grayscale(file_path):
    image = cv2.imread(file_path)
    gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    _cache_image(gray_image, file_path)

def hsv(file_path):
    image = cv2.imread(file_path)
    hsv_image = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
    _cache_image(hsv_image, file_path)



def hue_shifted(file_path, hue=50):
    image = cv2.imread(file_path)
    height, width, channels = image.shape
    emptyPictureArray = np.zeros((height, width, 3), dtype=np.uint8)
    for y in range(height):
        for x in range(width):
            for c in range(channels):
                new_value = image[y, x, c] + hue
                # Clip the value to stay within [0, 255]
                emptyPictureArray[y, x, c] = np.clip(new_value, 0, 255)
    _cache_image(emptyPictureArray, file_path)

def smoothing(file_path):
    image = cv2.imread(file_path)
    smoothed_image = cv2.blur(image, ksize=(15, 15))
    _cache_image(smoothed_image, file_path)


def rotation(file_path, rotation_angle=90):
    image = cv2.imread(file_path)
    if rotation_angle == 90:
        rotated_image = cv2.rotate(image, cv2.ROTATE_90_CLOCKWISE)
    elif rotation_angle == 180:
        rotated_image = cv2.rotate(image, cv2.ROTATE_180)
    else:
        print("Invalid angle. Use 90 or 180.")
        return
    _cache_image(rotated_image, file_path)

def open_image():
    """
    Function called from the menu to open an image.
    """
    # Ask user to choose an image file
    file_path = filedialog.askopenfilename(
        filetypes=[("Image files", "*.jpg *.jpeg *.png *.gif *.bmp")]
    )
    if file_path:
        _open_image(file_path)

def _cache_image(image, file_path):
    opened_image_basename = os.path.basename(file_path)
    opened_image_path = os.path.dirname(file_path)
    newfname = "cache/" + opened_image_basename
    cv2.imwrite(newfname, image)
    print(f"Image cached as '{newfname}'.")
    _open_image(newfname)


def _save_image(file_path):
    image = cv2.imread(file_path)
    opened_image_basename = os.path.basename(file_path)
    opened_image_path = os.path.dirname(file_path)
    newfname = opened_image_path + '/../' + opened_image_basename
    cv2.imwrite(newfname, image)
    print(f"Image saved as '{newfname}'.")
    _open_image(newfname)


def _open_image(file_path):
    """
    Open and display an image in the GUI.
    Params:
    - file_path: Path to the image file.
    """
    # Open with cv2 to get dimensions
    imgcv2 = cv2.imread(file_path)
    height, width, channels = imgcv2.shape

    # Open and resize image (optional)
    img = Image.open(file_path)
    img = img.resize((height, width), Image.LANCZOS)  # Resize to fit frame
    tk_img = ImageTk.PhotoImage(img)

    # Update label inside frame with the correct dimensions
    image_label.config(image=tk_img, height=height, width=width)

    global OPENED_IMAGE
    OPENED_IMAGE = file_path  # Store opened image in global variable, to access later if needed
    
    print("Opened image:", file_path)


if __name__ == "__main__":

# Main window
    root = tk.Tk()
    root.title("Image Viewer")
    root.geometry("800x600")
    root.config(bg="white")
    icon = tk.PhotoImage(file='icon.png')
    root.tk.call('wm', 'iconphoto', root._w, icon)
    root.minsize(800, 600)

# Menus
    menu = tk.Menu(root)
    root.config(menu=menu)
    file_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="File", menu=file_menu)
    file_menu.add_command(label="Open Image", command=open_image)
    file_menu.add_command(label="Save Image", command=lambda: _save_image(OPENED_IMAGE))
    file_menu.add_command(label="Exit", command=root.quit)

    test_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Test", menu=test_menu)
    test_menu.add_command(label="Padding", command=lambda: padding(OPENED_IMAGE, border_width=50) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Crop", command=lambda: crop(OPENED_IMAGE) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Resize", command=lambda: resize(OPENED_IMAGE) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Copy", command=lambda: copy(OPENED_IMAGE) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Greyscale", command=lambda: grayscale(OPENED_IMAGE) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Hsv", command=lambda: hsv(OPENED_IMAGE) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Hue Shifted", command=lambda: hue_shifted(OPENED_IMAGE, hue=50) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Smoothed", command=lambda: smoothing(OPENED_IMAGE) if OPENED_IMAGE is not None else print("No image opened."))
    test_menu.add_command(label="Rotated", command=lambda: rotation(OPENED_IMAGE, rotation_angle=90) if OPENED_IMAGE is not None else print("No image opened."))


    clipboard_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Clipboard", menu=clipboard_menu)

    image_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Image", menu=image_menu)

    tools_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Tools", menu=tools_menu)

    shapes_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Shapes", menu=shapes_menu)

    colors_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Colors", menu=colors_menu)

    layer_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Layer", menu=layer_menu)

    filter_menu = tk.Menu(menu, tearoff=0)
    menu.add_cascade(label="Filter", menu=filter_menu)
#

# Frame to hold image
    imgframe = tk.Frame(root, width=500, height=500, bg="lightgray", relief="sunken", bd=2)
    imgframe.pack(side="top", pady=10)

# Label to display image
    image_label = tk.Label(imgframe, width=500, height=500, bg="white")
    image_label.pack(expand=True)

    root.mainloop()