from hashlib import sha1
import hmac
from base64 import b64encode
from urllib import urlencode
from datetime import datetime

def paypal_urlencode(s):
    encode = lambda x: x if x in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890_+" else '%%%x' % ord(x)
    return ''.join(map(encode, s.replace(' ','+')))

def paypal_authorisation(token, ep, consumer, method="POST", sandbox=True):
    params = OrderedDict(
        oauth_consumer_key=consumer['key'],
        oauth_version='1.0',
        oauth_signature_method="HMAC-SHA1",
        oauth_token=token['key'],
        oauth_timestamp=datetime.now().strftime('%s')
    )
    print params['oauth_timestamp']
    key = "&".join((paypal_urlencode(consumer['secret']), paypal_urlencode(token['secret'])))
    sig_base = "&".join((method, paypal_urlencode(ep), paypal_urlencode("oauth_consumer_key=%(oauth_consumer_key)s&oauth_signature_method=%(oauth_signature_method)s&oauth_timestamp=%(oauth_timestamp)s&oauth_token=%(oauth_token)s&oauth_version=%(oauth_version)s" % params)))
    h= hmac.new(key.encode('ascii'), sig_base.encode('ascii'), sha1)
    signature=b64encode(h.digest())
    print dict(key=key,sigbase=sig_base.encode('ascii'), sig=signature)

    return "token=%s,signature=%s,timestamp=%s" % (token['key'], signature, params['oauth_timestamp'])