import hashlib

from django.core.files.storage import default_storage as store
from django.http import HttpResponse
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_POST
import magic

from lemonauth import tokens
from lemoncurry.utils import absolute_url
from .. import error

ACCEPTED_MEDIA_TYPES = (
    "image/gif",
    "image/jpeg",
    "image/png",
)


@csrf_exempt
@require_POST
def media(request):
    token = tokens.auth(request)
    if "file" not in request.FILES:
        raise error.bad_req(
            "a file named 'file' must be provided to the media endpoint"
        )
    file = request.FILES["file"]
    if file.content_type not in ACCEPTED_MEDIA_TYPES:
        raise error.bad_req("unacceptable file type {0}".format(file.content_type))

    mime = None
    sha = hashlib.sha256()
    for chunk in file.chunks():
        if mime is None:
            mime = magic.from_buffer(chunk, mime=True)
        sha.update(chunk)

    if mime != file.content_type:
        raise error.bad_req(
            "detected file type {0} did not match specified file type {1}".format(
                mime, file.content_type
            )
        )

    path = "mp/{0[0]}/{2}.{1}".format(*mime.split("/"), sha.hexdigest())
    path = store.save(path, file)
    url = absolute_url(request, store.url(path))

    res = HttpResponse(status=201)
    res["Location"] = url
    return res