# -*- coding: utf-8 -*-
__copyright__ = "Copyright (c) 2014-2017 Agora.io, Inc."


import hmac
import ctypes
import warnings
from hashlib import sha1


warnings.warn('The DynamicKey4 module is deprecated', DeprecationWarning)


def generatePublicSharingKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs):
    return generateDynamicKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs, "APSS")


def generateRecordingKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs):
    return generateDynamicKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs, "ARS")


def generateMediaChannelKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs):
    return generateDynamicKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs, "ACS")


def generateDynamicKey(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs, servicetype):
    uid = ctypes.c_uint(uid).value
    randomInt = ctypes.c_uint(randomInt).value
    signature = generateSignature(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs, servicetype)
    version = '{0:0>3}'.format(4)
    ret = version + str(signature) + appID + '{0:0>10}'.format(unixTs) + "%.8x" % (int(randomInt) & 0xFFFFFFFF) + \
        '{:0>10}'.format(expiredTs)
    return ret


def generateSignature(appID, appCertificate, channelName, unixTs, randomInt, uid, expiredTs, servicetype):
    key = "\x00" * (32 - len(appID)) + appID
    content = servicetype + key + '{:0>10}'.format(unixTs) + "%.8x" % (int(randomInt) & 0xFFFFFFFF) + \
        str(channelName) + '{:0>10}'.format(uid) + '{:0>10}'.format(expiredTs)
    signature = hmac.new(appCertificate.encode('utf-8'), content.encode('utf-8'), sha1).hexdigest()
    return signature