"""S3 Image methods."""
# Based on: https://gist.github.com/ghandic/a48f450f3c011f44d42eea16a0c7014d
from io import BytesIO
import logging
import os

import boto3
from PIL import Image


class S3ImageInvalidExtension(Exception):
    """Error for invalid extension."""

    pass


class S3ImageUploadFailed(Exception):
    """Error for failed upload."""

    pass


def transform_image(image_name, image_object):
    """Transform a Pillow image to match ripper spec."""
    # if the image is not square
    if image_object.width != image_object.height:
        # Check how much longer the long side is
        long_edge = max(image_object.width, image_object.height)

        print('Correcting non-square image to {}x{}px.'.format(
            long_edge, long_edge))
        # Reshape
        image_object = image_object.resize((long_edge, long_edge))

    # Convert Mode
    if image_object.mode != 'RGB':
        print('Converting {} to RGB.'.format(image_name))
        image_object = image_object.convert('RGB')

    # Upscale dimensions
    if image_object.width < 3000:
        print('Upscaling image {} to 3000x3000px.'.format(image_name))
        image_object = image_object.resize((3000, 3000))

    return image_object


def get_image_from_s3(bucket, key):
    """Get an image from an S3 source as a Pillow object."""
    # Get S3 object
    s3_client = boto3.client('s3')
    file_byte_string = s3_client.get_object(Bucket=bucket, Key=key)[
        'Body'].read()
    print('Converting object to Image')

    return Image.open(BytesIO(file_byte_string))


def save_image_to_s3(img, bucket, key, dpi=None):
    """Save a Pillow image object to an S3 target from memory."""
    if not dpi:
        dpi = (72, 72)
    print('Using dpi: {}'.format(dpi))
    file_name = os.path.split(key)[1]
    # Transform image
    print('Transforming {}'.format(file_name))
    img = transform_image(file_name, img)

    buffer = BytesIO()
    ext = __get_safe_ext(file_name)
    print('Extension is: {}'.format(ext))

    try:
        print('Saving: {} as {}'.format(file_name, key))
        img.save(buffer, ext, dpi=dpi)
    except Exception as e:
        logging.exception('Save failed!')
        print('Error - {} ({}):, {}'.format(type(e), e.args, str(e)))

    buffer.seek(0)  # Rewind buffer for saving to S3

    print('Puting {} to {}'.format(key, bucket))
    s3_client = boto3.client('s3')
    sent_data = s3_client.put_object(
        Body=buffer, Key=key, Bucket=bucket, ContentType='image/tiff')

    if sent_data['ResponseMetadata']['HTTPStatusCode'] != 200:
        raise S3ImageUploadFailed(
            'Failed to upload image {} to bucket {}'.format(key, bucket))


def __get_safe_ext(key):
    ext = os.path.splitext(key)[-1].strip('.').upper()
    if ext in ['JPG', 'JPEG']:
        return 'JPEG'
    elif ext in ['PNG']:
        return 'PNG'
    elif ext in ['TIF', 'TIFF']:
        return 'TIFF'
    else:
        raise S3ImageInvalidExtension('Extension is invalid')