import datetime
import json

from django.core.exceptions import ValidationError
from django.http import response
from django.views.decorators.csrf import csrf_exempt

import mainsite.models as mainModels

from . import models


def authentify(data, payload):
    """returns whether the request's authentification is correct"""
    required = ["keyId", "timestamp", "hmac"]
    for field in required:
        if field not in data:
            return response.HttpResponseForbidden(
                'Missing required field "{}"'.format(field)
            )
    try:
        key = models.ApiKey.objects.get(id=data["keyId"])
    except models.ApiKey.DoesNotExist:
        return response.HttpResponseForbidden("Bad authentication")

    if not key.isCorrect(data["timestamp"], data["hmac"], payload):
        return response.HttpResponseForbidden("Bad authentication")


def apiView(required=[]):
    def decorator(fct):
        @csrf_exempt
        def wrap(request, *args, **kwargs):
            try:
                data = json.loads(request.body.decode("utf-8"))
            except TypeError:
                return response.HttpResponseBadRequest("Bad packet format")
            except json.decoder.JSONDecodeError:
                return response.HttpResponseBadRequest("Bad json")

            try:
                authData = data["auth"]
                reqDataOrig = data["req"]
            except KeyError:
                return response.HttpResponseBadRequest("Bad request format")

            try:
                reqData = json.loads(reqDataOrig)
            except TypeError:
                return response.HttpResponseBadRequest("Bad packet format")
            except json.decoder.JSONDecodeError:
                return response.HttpResponseBadRequest("Bad inner json")

            for field in required:
                if field not in reqData:
                    return response.HttpResponseBadRequest(
                        "Missing field {}".format(field)
                    )

            authVal = authentify(authData, reqDataOrig)
            if authVal is not None:
                return authVal

            return fct(request, reqData, *args, **kwargs)

        return wrap

    return decorator


@apiView(required=["id", "url", "date"])
def publishApiView(request, data):
    """Publish a BOcal, and create the corresponding year if needed"""
    if mainModels.Publication.objects.filter(num=data["id"]).count() > 0:
        return response.HttpResponseBadRequest(
            "Un BOcal du même numéro est déjà présent ! Ajoutez celui-ci à la "
            "main si vous voulez vraiment faire ça."
        )

    try:
        year, month, day = [int(x) for x in data["date"].split("-")]
        date = datetime.date(year, month, day)
    except Exception:
        return response.HttpResponseBadRequest("Bad date")

    pub = mainModels.Publication(num=data["id"], url=data["url"], date=date)
    try:
        pub.full_clean()
    except ValidationError as e:
        return response.HttpResponseBadRequest("Invalid data: {}".format(e))
    pub.save()

    pub.createPubYear()

    return response.HttpResponse("OK")