"""Convert image to ASCII."""

from io import BytesIO

from PIL import Image

import boto3

client = boto3.client(
    's3',
    endpoint_url='http://localstacks3:4566',
    use_ssl=False,
    aws_access_key_id='abc',
    aws_secret_access_key='123'
)

# ascii conversion based on the following...
# https://www.hackerearth.com/practice/notes/beautiful-python-a-simple-ascii-art-generator-from-images/


def handler(event, context):
    """Entrypoint."""
    print(event)
    print(context)

    image_id = event['id']
    bucket_id = event['bucket_id']

    data = client.get_object(
        Bucket=bucket_id,
        Key=image_id
    )
    body = data['Body'].read()

    raw_data = BytesIO(body)
    image = Image.open(raw_data)

    image_ascii = convert_image_to_ascii(image, 150)
    print(image_ascii)
    return {
        'image': image_ascii
    }


def convert_image_to_ascii(image, new_width):
    """Image to ASCII characters."""
    image = scale_image(image, new_width)
    image = convert_to_grayscale(image)
    pixels_to_chars = map_pixels_to_ascii_chars(image)
    image_ascii = [
        pixels_to_chars[index: index + new_width]
        for index in range(0, len(pixels_to_chars), new_width)
    ]
    return '\n'.join(image_ascii)


def scale_image(image, new_width):
    """Resize image."""
    (original_width, original_height) = image.size
    aspect_ratio = original_height / float(original_width)
    new_height = int(aspect_ratio * new_width)
    new_image = image.resize((new_width, new_height))
    return new_image


def convert_to_grayscale(image):
    """Grayscale image."""
    return image.convert('L')


def map_pixels_to_ascii_chars(image, range_width=25):
    """Convert pixels to ASCII."""
    ascii_chars = ['#', '?', '%', '.', 'S', '+', '.', '*', ':', ',', '@']
    pixels_in_image = list(image.getdata())
    pixels_to_chars = [
        ascii_chars[pixel_value // range_width]
        for pixel_value in pixels_in_image
    ]
    return ''.join(pixels_to_chars)