import os
from io import BytesIO

from PIL import Image


def rescale_image_jpeg(image_object, base_width=1020):
    img = Image.open(image_object)
    icc_profile = img.info.get('icc_profile')  # remember color profile to not mess up colors
    width_percent = (base_width / float(img.size[0]))
    height = int((float(img.size[1]) * float(width_percent)))

    img = img.resize((base_width, height), Image.LANCZOS)
    img_bytes = BytesIO()
    img.save(img_bytes, 'JPEG', quality=90, optimize=True, icc_profile=icc_profile)

    return img_bytes


def rescale_image_png(image_object, base_width=1020):
    image_object = Image.open(image_object)
    wpercent = (base_width / float(image_object.size[0]))
    hsize = int((float(image_object.size[1]) * float(wpercent)))
    img = image_object.resize((base_width, hsize), Image.LANCZOS)

    im_io = BytesIO()
    img.save(im_io, 'PNG', quality=90)
    return im_io


def get_filetype(name):
    try:
        return os.path.splitext(name)[1]
    except Exception:
        return '.jpeg'


def is_file_type_allowed(filename, image_only=False):
    is_file_allowed = False
    allowed_file_types = ['.pdf', '.docx', '.xlsx', '.css', '.mp4', '.mov']
    allowed_image_types = ['.png', '.jpg', '.jpeg', '.gif', '.webp']
    check_list = allowed_image_types
    if not image_only:
        check_list += allowed_file_types

    for file_type in check_list:
        if filename.lower().endswith(file_type):
            is_file_allowed = True

    return is_file_allowed


def strip_image_meta(image_object, file_format):
    image_object = Image.open(image_object)

    data = list(image_object.getdata())
    image_without_exif = Image.new(image_object.mode, image_object.size)
    image_without_exif.putdata(data)

    im_io = BytesIO()
    image_without_exif.save(im_io, file_format)
    return im_io


# TODO this whole file needs proper documentation, refactoring, and testing
# TODO also add env variable to define which images sizes should be compressed
# filetype argument can not be optional, otherwise this function will treat all images as if they were a jpeg
# Because it's no longer optional, no reason to return it
def handle_image(request, image_object, filetype):
    try:
        Image.open(image_object).verify()
    except Exception:
        return None

    file_format = None
    if filetype == '.jpeg' or filetype == '.jpg':
        file_format = 'JPEG'
    if filetype == '.png':
        file_format = 'PNG'
    if filetype == '.webp':
        file_format = 'WEBP'

    if (image_object.size / 1000) > 500:  # if larger than 500 kb compress
        if filetype == '.jpeg' or filetype == '.jpg':
            return rescale_image_jpeg(image_object)
        if filetype == '.png':
            return rescale_image_png(image_object)
    else:
        return strip_image_meta(image_object, file_format)

    # TODO webp and gifs bypass the scaling and metadata checks, fix
    return image_object