import os
from io import BytesIO

import boto3
from PIL import Image
from django.conf import settings


def store_in_bucket(data, key, content_type, public_read=False):
    boto3.client('s3').put_object(
        Bucket=settings.STORAGE_BUCKET,
        Key=key,
        ContentType=content_type,
        ACL=('public-read' if public_read else 'private'),
        Body=data
    )


def store_file_in_bucket(fileobj, key, public_read=False):
    boto3.client('s3').upload_fileobj(
        fileobj, settings.STORAGE_BUCKET, key,
        ExtraArgs=dict(
            ContentType=guess_content_type(fileobj),
            ContentDisposition='inline; filename="{}"'.format(fileobj.name),
            ACL=('public-read' if public_read else 'private')
        )
    )


def get_bucket_object(key):
    return boto3.resource('s3').Object(settings.STORAGE_BUCKET, key)


def get_signed_bucket_url(key, expire_minutes=10):
    return boto3.client('s3').generate_presigned_url(
        'get_object',
        Params=dict(
            Bucket=settings.STORAGE_BUCKET,
            Key=key
        ),
        ExpiresIn=(expire_minutes * 60)
    ) if key else None


class ImageManipulator(object):
    def resize(self, object_key, max_width):
        if not max_width:
            max_width = 640

        if not os.path.exists('tmp'):
            os.makedirs('tmp')

        temp_dir = os.path.abspath('tmp')
        obj_path = os.path.join(temp_dir, object_key)

        obj = get_bucket_object(object_key)
        obj.download_file(obj_path)

        in_img = None
        out_img = BytesIO()

        try:
            in_img = Image.open(obj_path, 'r')
        except IOError:
            print("Cannot open file {}".format(object_key))

        if in_img.width > max_width:
            in_img.thumbnail((in_img.height, max_width), Image.ANTIALIAS)
            in_img.save(out_img, in_img.format)

            out_img.seek(0)
            out_img.name = object_key
            store_file_in_bucket(out_img, object_key)

        os.remove(obj_path)