from __future__ import print_function
import json, re, sys
from argparse import ArgumentParser
from getpass import getpass
from requests import Session
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry
if sys.version_info[0] < 3:
  from urlparse import urlparse, parse_qs
  input = raw_input
else:
  from urllib.parse import urlparse, parse_qs


class OlinfoLiker:

  def __init__(self, usr, pwd):
    self.__session = Session()
    retry = Retry(backoff_factor=.1, status_forcelist=[429])
    adapter = HTTPAdapter(max_retries=retry)
    self.__session.mount('https://', adapter)
    self.__buffer = []
    self.__lastID = 0
    self.__login(usr, pwd)
    self.__setCSRF()

  def __str__(self):
    return '%s loves everyone!' % self.__username

  def like(self, target=None):
    post = self.__getPost(target)
    url = 'https://forum.olinfo.it/post_actions'
    data = {'id': post['id'], 'post_action_type_id': 2}
    headers = {
        'X-CSRF-Token': self.__csrf,
        'X-Requested-With': 'XMLHttpRequest'
    }
    r = self.__session.post(url, headers=headers, json=data)
    data = self.__parseJSON(r.text)
    print(self.__username, 'likes', post['username'], '(id: %d)' % post['id'])

  def __login(self, usr, pwd):
    url = 'https://training.olinfo.it/api/user'
    data = {'username': usr, 'password': pwd, 'action': 'login'}
    r = self.__session.post(url, json=data)
    try:
      data = self.__parseJSON(r.text)
    except:
      raise Exception('Login fallito')

    url = 'https://forum.olinfo.it/session/sso?return_path=%2F'
    r = self.__session.get(url)
    query = parse_qs(urlparse(urlparse(r.url).fragment).query)

    url = 'https://training.olinfo.it/api/sso'
    payload = {'payload': query['sso'][0], 'sig': query['sig'][0]}
    r = self.__session.post(url, json=payload)
    data = self.__parseJSON(r.text)

    url = 'https://forum.olinfo.it/session/sso_login?' + data['parameters']
    r = self.__session.get(url)

    self.__username = r.headers['X-Discourse-Username']
    print('Login completato (%s)' % self.__username)

  def __parseJSON(self, text):
    try:
      data = json.loads(text)
    except:
      raise Exception(re.search('<title>(.*?)</title>', text).group(1))
    if 'error' in data:
      raise Exception(data['error'])
    if 'errors' in data:
      for e in data['errors']:
        raise Exception(e)
    return data

  def __setCSRF(self):
    url = 'https://forum.olinfo.it/session/csrf.json'
    r = self.__session.get(url)
    data = self.__parseJSON(r.text)
    self.__csrf = data['csrf']

  def __getPostsTarget(self, target):
    url = 'https://forum.olinfo.it/user_actions.json?offset=%d&username=%s&filter=5' % (
        self.__lastID, target)
    r = self.__session.get(url)
    self.__lastID += 30
    try:
      data = self.__parseJSON(r.text)
    except:
      raise Exception('Utente non trovato')
    if not data['user_actions']:
      raise Exception('Nessun post trovato')
    ids = [i['post_id'] for i in data['user_actions']]
    while ids:
      url = 'https://forum.olinfo.it/posts.json?before=%d' % ids[0]
      r = self.__session.get(url)
      data = self.__parseJSON(r.text)
      for i in data['latest_posts']:
        if i['id'] not in ids:
          continue
        ids.remove(i['id'])
        for j in i['actions_summary']:
          if 'acted' in j:
            break
        else:
          self.__buffer.append(i)

  def __getPostsUnTarget(self):
    url = 'https://forum.olinfo.it/posts.json'
    if self.__lastID:
      if self.__lastID <= 1:
        raise Exception('Nessun post trovato')
      url += '?before=%d' % self.__lastID
    else:
      self.__lastID = 99999
    r = self.__session.get(url)
    data = self.__parseJSON(r.text)
    self.__buffer = []
    for i in data['latest_posts']:
      if i['id'] <= self.__lastID:
        self.__lastID = i['id'] - 1
      if self.__username == i['username']:
        continue
      for j in i['actions_summary']:
        if 'acted' in j:
          break
      else:
        self.__buffer.append(i)

  def __getPost(self, target):
    while not self.__buffer:
      if target:
        self.__getPostsTarget(target)
      else:
        self.__getPostsUnTarget()
    return self.__buffer.pop()


def main():
  parser = ArgumentParser()
  parser.add_argument(
      '-t',
      '--target',
      type=str,
      help='utente a cui mettere like',
      metavar='USER')
  parser.add_argument(
      '-l',
      '--likes',
      type=int,
      default=50,
      help='numero massimo di post a cui mettere like')
  args = parser.parse_args()

  username = input('Username: ')
  password = getpass()

  try:
    liker = OlinfoLiker(username, password)
    for i in range(args.likes):
      liker.like(target=args.target)
  except Exception as e:
    print('Errore:', e, file=sys.stderr)


if __name__ == '__main__':
  main()