# SPDX-License-Identifier: BSD-3-Clause
# Copyright (c) 2021, The Wownero Project.

import os
from io import BytesIO

import pyqrcode
from PIL import Image, ImageDraw

import settings


def qr_png(
        address: str,
        size=settings.PIL_IMAGE_DIMENSIONS,
        color_from=(210, 83, 200),
        color_to=(255, 169, 62)
) -> BytesIO:
    """Pretty QR c0dez j00"""
    created = pyqrcode.create(address, error='L')
    buffer = BytesIO()
    result = BytesIO()
    created.png(buffer, scale=14, quiet_zone=2)

    im = Image.open(buffer)
    im = im.convert("RGBA")
    im.thumbnail(size)

    im_data = im.getdata()

    # make black color transparent
    im_transparent = []
    for color_point in im_data:
        if sum(color_point[:3]) == 255 * 3:
            im_transparent.append(color_point)
        else:
            # get rid of the subtle grey borders
            alpha = 0 if color_from and color_to else 1
            im_transparent.append((0, 0, 0, alpha))
            continue

    if not color_from and not color_to:
        im.save(result, format="PNG", quality=settings.PIL_QUALITY, optimize=settings.PIL_OPTIMIZE)
        result.seek(0)
        return result

    # turn QR into a gradient
    im.putdata(im_transparent)

    gradient = Image.new('RGBA', im.size, color=0)
    draw = ImageDraw.Draw(gradient)

    for i, color in enumerate(gradient_interpolate(color_from, color_to, im.width * 2)):
        draw.line([(i, 0), (0, i)], tuple(color), width=1)

    im_gradient = Image.alpha_composite(gradient, im)
    im_gradient.save(result, format="PNG", quality=settings.PIL_QUALITY, optimize=settings.PIL_OPTIMIZE)

    result.seek(0)
    return result


def gradient_interpolate(color_from, color_to, interval):
    det_co = [(t - f) / interval for f, t in zip(color_from, color_to)]
    for i in range(interval):
        yield [round(f + det * i) for f, det in zip(color_from, det_co)]