import base64
import os
import zlib, hmac, hashlib, time, json


class APICredentials:
    """
    Stores credentials required to request our API.
    """
    @property
    def user_id(self):
        """
        Set your user ID to the one defined on the User Settings page.
        """
        return "1234567890abcdefghijklmnopqrstu"

    @property
    def secret(self):
        """
        Set your API key to a value defined on the Integration Keys page. 
        """
        return "1234567890abcdefghijklmnopqrstuvwxyz1234"


class APIParams(object):
    """
    Provides API authentication. Learn more at:
        https://docs.edgecast.com/video/#Develop/Versioned-API.htm    
    """
    def __init__(self, credentials):
        self.credentials = credentials

    def get_params(self, data):
        """
        Encodes and signs <data> into the expected format and returns it.
        """
        data = self._get_params(**data)
        data.update(data)
        return data

    def _get_msg(self, msg=None):
        """
        Encodes and returns the 'msg' parameter.
        """
        msg = msg if msg else {}

        msg.update({
            '_owner': self.credentials.user_id,
            '_timestamp': int(time.time())
        })

        msg = json.dumps(msg)
        msg_compressed = zlib.compress(msg.encode(), 9)
        return base64.b64encode(msg_compressed).strip()

    def _get_params(self, **msg):
        """
        Returns the message and its signature.
        """
        msg = self._get_msg(msg)

        sig = hmac.new(
            self.credentials.secret.encode(), msg, hashlib.sha256
        ).hexdigest()

        return {
            'msg': msg,
            'sig': sig
        }