###
# Copyright (c) Ben Maurer

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
###

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):
    """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

    return """<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,
        }


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')
    
    
    
    params = urllib.urlencode ({
	    'privatekey': private_key,
            'remoteip' : remoteip,
	    'challenge': recaptcha_challenge_field,
	    'response' : 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])