import os
from io import BytesIO

import PIL.Image
from django.conf import settings
from django.core import serializers
from django.core.files.images import ImageFile

from wagtail.images import get_image_model

Image = get_image_model()


def get_test_image_filename(image, filterspec):
    """
    Get the generated filename for a resized image
    """
    name, ext = os.path.splitext(os.path.basename(image.file.name))
    # Use the correct extension if the filterspec is a format operation.
    if "format-" in filterspec:
        ext = "." + filterspec.split("format-")[1].split("-")[0].split(".")[0].replace(
            "jpeg", "jpg"
        )
    return f"{settings.MEDIA_URL}images/{name}.{filterspec}{ext}"


def get_test_image_file(filename="test.png", colour="white", size=(640, 480)):
    f = BytesIO()
    image = PIL.Image.new("RGBA", size, colour)
    image.save(f, "PNG")
    return ImageFile(f, name=filename)


def get_test_image_file_avif(filename="test.png", colour="white", size=(640, 480)):
    f = BytesIO()
    image = PIL.Image.new("RGBA", size, colour)
    image.save(f, "AVIF")
    return ImageFile(f, name=filename)


def get_test_image_file_jpeg(filename="test.jpg", colour="white", size=(640, 480)):
    f = BytesIO()
    image = PIL.Image.new("RGB", size, colour)
    image.save(f, "JPEG")
    return ImageFile(f, name=filename)


def get_test_image_file_webp(filename="test.webp", colour="white", size=(640, 480)):
    f = BytesIO()
    image = PIL.Image.new("RGB", size, colour)
    image.save(f, "WEBP")
    return ImageFile(f, name=filename)


def get_test_image_file_tiff(filename="test.tiff", colour="white", size=(640, 480)):
    f = BytesIO()
    image = PIL.Image.new("RGB", size, colour)
    image.save(f, "TIFF")
    return ImageFile(f, name=filename)


def get_test_image_file_svg(
    filename="test.svg", width=100, height=100, view_box="0 0 100 100"
):
    img = f"""
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" width="{width}" height="{height}" viewBox="{view_box}">
</svg>
    """
    f = BytesIO(img.strip().encode("utf-8"))
    return ImageFile(f, filename)


def get_test_bad_image():
    # Create an image with a missing file, by deserializing from a python object
    # (which bypasses FileField's attempt to read the file)
    return list(
        serializers.deserialize(
            "python",
            [
                {
                    "fields": {
                        "title": "missing image",
                        "height": 100,
                        "file": "original_images/missing-image.jpg",
                        "width": 100,
                    },
                    "model": "wagtailimages.image",
                }
            ],
        )
    )[0].object