kicknotifier.py

#!/usr/bin/env python
import requests, json, smtplib, sys
from lxml import etree
from StringIO import StringIO
from time import sleep, ctime
from random import random
from email.MIMEMultipart import MIMEMultipart
from email.MIMEText import MIMEText
from getpass import getpass

class NoPledgesError(Exception):
    pass

class InvalidEmailError(Exception):
    pass

class InvalidURLError(Exception):
    pass

class InvalidChoiceError(Exception):
    pass

def validate_email(email):
    try:
        email_split = email.split('@')
        assert len(email_split) == 2
        assert len(email_split[1].split('.')) == 2
    except AssertionError as e:
        print "Error: Invalid email."
        raise InvalidEmailError
    return

def setup():
    #prompt user for setup info
    print "Please enter configuration or press enter to load config file"
    print '--------------------------------------------------------------------------------'
    email_recipient = raw_input('Email recipient: ')
    if email_recipient == '':
        try:
            pass
            #read from file
        except IOError as e:
            print "Error: Failed to read configuration file."
            raise
    else:
        validate_email(email_recipient)
        email_user = raw_input('Email server user (default: same): ') or email_recipient
        email_pswd = getpass('Email server pswd: ')
        email_addr = raw_input('Email server addr (default: smtp.gmail.com): ') or 'smtp.gmail.com'
        assert type(email_addr) == str
        email_port = raw_input('Email server port (default: 587): ') or 587
        assert type(email_port) == int
        assert 1 <= email_port <= 65536

    url = raw_input('Enter project URL: ')
    return setup_part2(email_recipient, email_user, email_pswd, email_addr, email_port, url)

def setup_part2(email_recipient, email_user, email_pswd, email_addr, email_port, url):
    max_reward_desc = 60

    print 'Fetching data...'

    #validate
    try:
        split_url = url.split('projects/')
        assert len(split_url) == 2
        assert split_url[0] in ('https://www.kickstarter.com/', 'https://www.kickstarter.com/')
        assert len(split_url[1].split('/')) > 1
    except AssertionError as e:
        print "Error: Invalid URL."
        raise InvalidURLError

    #test cases:
    #https://www.kickstarter.com/projects/2093152267/losswords-a-game-of-literary-portions/comments
    #https://www.kickstarter.com/projects/2093152267/losswords-a-game-of-literary-portions?ref=discover_potd
    #https://www.kickstarter.com/projects/2093152267/losswords-a-game-of-literary-portions/pledge/new?clicked_reward=false&ref=discover_potd


    #clean the base url
    url = '/'.join(url.split('/')[:6])
    url = url.split('?')[0]
    pledge_url = url + '/pledge/new'

    #get reward levels
    session = requests.Session()
    r = session.get(pledge_url)
    session.close()
    rt = etree.parse(StringIO(r.text), etree.HTMLParser(encoding = 'UTF-8'))
    project_title = rt.xpath('//*[contains(@class, "project-context__title")]')[0].text.\
            replace(u"\u2018", "'").replace(u"\u2019", "'").\
            replace(u"\u2122", "tm")
    reward_data = [json.loads(i.attrib['data-reward']) for i in rt.xpath('//*[contains(concat(" ", @class, " "), " pledge-selectable ")]')]

    if len(reward_data) == 0:
        print 'Error: Project has no active pledge levels.'
        raise NoPledgesException

    #prompt user to select reward level
    print '--------------------------------------------------------------------------------'
    for x in xrange(len(reward_data)):
        print '[{index: >2}] ${min: <5}: {desc}'.format(index = x+1,\
            min = int(reward_data[x].get('minimum')),\
            desc = ''.join(reward_data[x].get('reward').\
                    replace(u"\u2018", "'").replace(u"\u2019", "'").
                    replace(u"\u2122", "tm").\
                    splitlines())[0:max_reward_desc])
    print '--------------------------------------------------------------------------------'
    choice = raw_input('Choose reward (default: exit): ') or None
    if choice == None:
        sys.exit()

    #validate
    try:
        choice = int(choice)
        #fixup zero indexing
        choice -= 1
        assert 0 <= choice <= 99
    except:
        print "Error: Invalid choice."
        raise InvalidChoiceError

    #clean reward
    reward = reward_data[choice]
    reward['reward'] = reward['reward'].\
            replace(u"\u2018", "'").replace(u"\u2019", "'").\
            replace(u"\u2122", "tm")

    #done
    return {'pledge_url': pledge_url,\
            'project_title': project_title,\
            'reward': reward_data[choice],\
            'email_recipient': email_recipient,\
            'email_user': email_user,\
            'email_pswd': email_pswd,\
            'email_addr': email_addr,\
            'email_port': email_port}

def monitor(config):
    reward = config['reward']
    sleep_time = 8
    sleep_rand = 4
    session = requests.Session()

    print 'Monitoring... (sleep {sleep_time}+/-{sleep_rand}sec)'.format(sleep_time = sleep_time, sleep_rand = sleep_rand)

    while True:
        url = reward['urls']['api']['reward']
        sig = url.split("signature=",1)[1].split('.')
        print(ctime(float(sig[0])) + " hash:" + sig[1])

        r = session.get(url)
        reward = json.loads(r.text)
        remaining = reward['remaining']
        if remaining > 0:
            break
        else:
            sleep(sleep_time + random() * sleep_rand)

def send_email(config):
    max_reward_desc = 40

    print('Composing email...')
    message = MIMEMultipart()
    message['From'] = 'noreply'
    message['To'] = config['email_recipient']
    message['Subject'] = 'KSMONITOR ALERT - [{project_title}]'.format(project_title = config['project_title'])
    html = """<html><head></head><body><p>The requested reward is available!<br><br><a href="{pledge_url}">{desc}</a></p></body></html>""".\
            format(pledge_url = config['pledge_url'], desc = ''.join(config['reward'].get('reward').splitlines()))
    message.attach(MIMEText(html, 'html'))

    print('Sending email...')
    smtp = smtplib.SMTP()
    smtp.connect(config['email_addr'], config['email_port'])
    smtp.ehlo()
    smtp.starttls()
    smtp.login(config['email_user'], config['email_pswd'])
    smtp.sendmail('noreply', config['email_recipient'], message.as_string())
    smtp.close()

    print('Email sent!')

def main(args):
    print ''
    #print len(args)
    #print args
    if len(args) > 0:
        config = setup_part2(*args[1:])
    else:
        config = setup()
    monitor(config)
    send_email(config)

if __name__ == '__main__':
    sys.exit(main(sys.argv))