''' API client for bocal-site '''

import json
import urllib.request
import hmac
import hashlib
from datetime import datetime


def sendReq(url):
    def send(payload, host):
        try:
            req = urllib.request.Request('http://{}/{}'.format(host, url),
                                         json.dumps(payload).encode('ascii'))
            req.add_header('Content-Type', 'application/json')
            handle = urllib.request.urlopen(req)
            code = handle.getcode()
            content = handle.read()
            handle.close()
            return (code, content.decode('utf-8'))
        except urllib.error.HTTPError as e:
            return (e.code, e.read().decode('utf-8'))

    def authentify(apiKey, payload):
        keyId, key = apiKey.split('$')
        keyId = int(keyId)
        time = datetime.now().timestamp()
        mac = hmac.new(key.encode('utf-8'),
                       msg=str(int(time)).encode('utf-8'),
                       digestmod=hashlib.sha256)
        mac.update(json.dumps(payload).encode('utf-8'))

        auth = {
            'keyId': keyId,
            'timestamp': time,
            'hmac': mac.hexdigest(),
        }

        return {
            'auth': auth,
            'req': payload,
        }

    def decorator(fct):
        ''' Decorator. Adds authentication layer. '''
        def wrap(host, apiKey, *args, **kwargs):
            innerReq = fct(*args, **kwargs)
            payload = authentify(apiKey, innerReq)
            return send(payload, host)
        return wrap

    return decorator


@sendReq(url='api/publish')
def publish(bocId, url, date):
    return {
        'id': bocId,
        'url': url,
        'date': date.strftime('%Y-%m-%d'),
    }