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

from . import models
import mainsite.models as mainModels


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')

    normPayload = json.dumps(payload)
    if not key.isCorrect(data['timestamp'], data['hmac'], normPayload):
        return response.HttpResponseForbidden('Bad authentication')


def apiView(required=[]):
    def decorator(fct):
        @csrf_exempt
        def wrap(request, *args, **kwargs):
            try:
                data = json.loads(request.body)
            except json.decoder.JSONDecoreError:
                return response.HttpResponseBadRequest("Bad json")

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

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

            authVal = authentify(authData, reqData)
            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:
        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")