import cv2 
import numpy as np
from PIL import Image, PngImagePlugin

def png_encode(im_name,extra):
        # Check text roundtripping

        im = Image.open(im_name)

        info = PngImagePlugin.PngInfo()
        info.add_text("TXT", extra)
        im.save("test.png",pnginfo=info)
        test = Image.open("test.png")
        print(test.text)
        return("test.png","")


def to_bin(data):
    """Convert `data` to binary format as string"""
    if isinstance(data, str):
        return ''.join([ format(ord(i), "08b") for i in data ])
    elif isinstance(data, bytes):
        return ''.join([ format(i, "08b") for i in data ])
    elif isinstance(data, np.ndarray):
        return [ format(i, "08b") for i in data ]
    elif isinstance(data, int) or isinstance(data, np.uint8):
        return format(data, "08b")
    else:
        raise TypeError("Type not supported.")
def decode(image_name,txt=None):
    try:
        BGRimage = cv2.imread(f"{image_name}")
        image = cv2.cvtColor(BGRimage, cv2.COLOR_BGR2RGB)   
        binary_data = ""
        for row in image:
            for pixel in row:
                r, g, b = to_bin(pixel)
                binary_data += r[-1]
                binary_data += g[-1]
                binary_data += b[-1]
        all_bytes = [ binary_data[i: i+8] for i in range(0, len(binary_data), 8) ]
        decoded_data = ""
        for byte in all_bytes:
            decoded_data += chr(int(byte, 2))
            if decoded_data[-5:] == "=====":
                break
        this = decoded_data[:-5].split("#####",1)[0]
        #this = eval(this)
    except Exception as e:
        this = e
    return this

def encode(image_name, secret_data,txt=None):
    msg=""
    BGRimage = cv2.imread(f"{image_name}")
    image = cv2.cvtColor(BGRimage, cv2.COLOR_BGR2RGB)    
    n_bytes = image.shape[0] * image.shape[1] * 3 // 8
    print("[*] Maximum bytes to encode:", n_bytes)
    secret_data1=secret_data
    while True:
        if len(secret_data1)+5 < (n_bytes):
            secret_data1 = f'{secret_data1}#####'
        elif len(secret_data1)+5 >= (n_bytes):
            break    
    secret_data = secret_data1    
    if len(secret_data) > n_bytes:
        msg ="Watermark is too large for Image Size"
        return image_name,msg
    secret_data += "====="
    data_index = 0
    binary_secret_data = to_bin(secret_data)
    data_len = len(binary_secret_data)
    for row in image:
        for pixel in row:
            r, g, b = to_bin(pixel)
            if data_index < data_len:
                pixel[0] = int(r[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index < data_len:
                pixel[1] = int(g[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index < data_len:
                pixel[2] = int(b[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index >= data_len:
                break
    return image,msg