import urllib2, urllib

API_SSL_SERVER="https://api-secure.recaptcha.net"

API_SERVER="http://api.recaptcha.net"

VERIFY_SERVER="api-verify.recaptcha.net"

class RecaptchaResponse(object):

    def __init__(self, is_valid, error_code=None):

        self.is_valid = is_valid

        self.error_code = error_code

def displayhtml (public_key, use_ssl = False, error = None, color = 'red'):

    """Gets the HTML to display for reCAPTCHA

    public_key -- The public api key

    use_ssl -- Should the request be sent over ssl?

    error -- An error message to display (from RecaptchaResponse.error_code)"""

    error_param = ''

    if error: error_param = '&error=%s' % error

    if use_ssl: server = API_SSL_SERVER

    else: server = API_SERVER

    if color not in ['red', 'white']: color = 'red'

    return """

<script type="text/javascript">  

  var RecaptchaOptions={theme:'%(Color)s'};  

</script>

<script type="text/javascript" src="%(ApiServer)s/challenge?k=%(PublicKey)s%(ErrorParam)s"></script>

<noscript>

  <iframe src="%(ApiServer)s/noscript?k=%(PublicKey)s%(ErrorParam)s" height="300" width="500" frameborder="0"></iframe><br />

  <textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>

  <input type='hidden' name='recaptcha_response_field' value='manual_challenge' />

</noscript>

""" % {

        'ApiServer'   : server,

        'PublicKey'   : public_key,

        'ErrorParam'  : error_param,

        'Color'       : color

      }

def submit (recaptcha_challenge_field,

            recaptcha_response_field,

            private_key,

            remoteip):

    """

    Submits a reCAPTCHA request for verification. Returns RecaptchaResponse

    for the request

    recaptcha_challenge_field -- The value of recaptcha_challenge_field from the form

    recaptcha_response_field -- The value of recaptcha_response_field from the form

    private_key -- your reCAPTCHA private key

    remoteip -- the user's ip address

    """

    if not (recaptcha_response_field and recaptcha_challenge_field and

            len (recaptcha_response_field) and len (recaptcha_challenge_field)):

        return RecaptchaResponse (is_valid = False, error_code = 'incorrect-captcha-sol')

    def encode_if_necessary(s):

        if isinstance(s, unicode):

            return s.encode('utf-8')

        return s

    params = urllib.urlencode ({

            'privatekey': encode_if_necessary(private_key),

            'remoteip' :  encode_if_necessary(remoteip),

            'challenge':  encode_if_necessary(recaptcha_challenge_field),

            'response' :  encode_if_necessary(recaptcha_response_field),

            })

    request = urllib2.Request (

        url = "http://%s/verify" % VERIFY_SERVER,

        data = params,

        headers = {

            "Content-type": "application/x-www-form-urlencoded",

            "User-agent": "reCAPTCHA Python"

            }

        )

    httpresp = urllib2.urlopen (request)

    return_values = httpresp.read ().splitlines ();

    httpresp.close();

    return_code = return_values [0]

    if (return_code == "true"):

        return RecaptchaResponse (is_valid=True)

    else:

        return RecaptchaResponse (is_valid=False, error_code = return_values [1])