#!/usr/bin/python3
import sys
from bs4 import BeautifulSoup
import requests
from requests.auth import HTTPBasicAuth
import io
import os
import time
from twitter import *
import tweepy
import difflib
# This imports from a file called 'constants'. This is at the moment, the file called 'constants_template'
import constants
import mail_handler

# Open a session for requests, which will be used throughout
session = requests.session()

# The config for being able to utilize twitter
cfg = { 
    "consumer_key"        : constants.cons_key,
    "consumer_secret"     : constants.cons_secret,
    "access_token"        : constants.access_token,
    "access_token_secret" : constants.access_token_secret 
}


# Setting the Twitter connection up
def get_api(cfg):
    auth = tweepy.OAuthHandler(cfg['consumer_key'], cfg['consumer_secret'])
    auth.set_access_token(cfg['access_token'], cfg['access_token_secret'])
    return tweepy.API(auth)

api = get_api(cfg)

 
# The main method for scraping Stads
def findGrades():

    # Calling the first get to Stads, such that I can get the correct link to follow
    stads = session.get('https://sbstads.au.dk/sb_STAP/sb/resultater/studresultater.jsp')

    # Getting the response with a meta tag, that I can then follow
    soup = BeautifulSoup(stads.text, 'html5lib')

    # Finding said meta tag
    meta_tag_redirect = session.get(soup.find('meta')['content'][6:])

    # This should return 200, since I hopefully found the correct meta tag 
    print(meta_tag_redirect.status_code)

    # Getting the url of the meta tag
    meta_tag_url = meta_tag_redirect.url

    # Trying to log in to WAYF
    wayf_login = session.post(meta_tag_url, data={'username':constants.USERNAME,'password':constants.PASSWORD})

    # Should return 200
    print(wayf_login.status_code)

    soup = BeautifulSoup(wayf_login.text, 'html5lib')

    
    # Finding SAMLResponse, such that I can parse it as a parameter, so WAYF will like me
    SAMLResponse = soup.find('input', {'name':'SAMLResponse'})['value']

    # Hopefully WAYF does in fact like me
    wayf = session.post('https://wayf.wayf.dk/module.php/saml/sp/saml2-acs.php/wayf.wayf.dk', data={'SAMLResponse':SAMLResponse})

    # If this returns 200, it does \o/
    print(wayf.status_code)

    # After concluding that WAYF liked me, we look at the response of WAYF 
    soup = BeautifulSoup(wayf.text, 'html5lib')

    # We then find the new SAMLResponse as well as a string 'RelayState'
    SAMLResponse = soup.find('input', {'name':'SAMLResponse'})['value']
    RelayState = soup.find('input', {'name':'RelayState'})['value']

    # We then do the last post, and after this, hopefully we can 'get' Stads
    SAMLAssertion = session.post('https://sbstads.au.dk/sb_STAP/saml/SAMLAssertionConsumer', data={'SAMLResponse':SAMLResponse,'RelayState':RelayState})

    # If this returns 200, it's go time!
    print(SAMLAssertion.status_code)

    # Given that the previous print returned 200, we can now get the source code of Stads
    resultater = session.get('https://sbstads.au.dk/sb_STAP/sb/resultater/studresultater.jsp')

    # Just to check that it returns 200, so we have access
    print(resultater.status_code)

    # Given that it returned 200, we can now get the source code and thus continue in our adventure to find the grades
    soup = BeautifulSoup(resultater.text, 'html5lib')

    return soup

   

def createGradeFile():
    soup = findGrades()

    newest_grades = soup.find_all('tr', {'class':'DataSelect'})
    
    if os.path.isfile('./temp_new_grades.log'):
        grade_file = open('temp_new_grades.log', 'r+')
    else:
        grade_file = open('temp_new_grades.log', 'w+')    

        
    for grade in newest_grades:
        grade_file.truncate()
        grade_file.write('%s \n' %str.strip(grade.find_all('td')[0].getText()))

    grade_file.close()

def diffGradeLists():

    createGradeFile()
    
    new_grade_file = open('./temp_new_grades.log', 'r+')
    old_grade_file = open('./old_grades.log', 'r+')

    diff = difflib.unified_diff(old_grade_file.readlines(), new_grade_file.readlines(), fromfile='file1', tofile='file2', lineterm="\n", n=0)
    lines = list(diff)[2:]
    added = [line[1:] for line in lines if line[0] == '+']
    removed = [line[1:] for line in lines if line[0] == '-']

    new_courses = []
    
    for line in added:
            if line not in removed:
                new_courses.append(line)
    
    new_grade_file.close()
    old_grade_file.close()
    return new_courses

def checker():

    new_grades = diffGradeLists()
    new_grade_file = open('./temp_new_grades.log', 'r+')
    old_grade_file = open('./old_grades.log', 'r+')

    grades_string = "New grade(s) in the following course(s):\n"
    
    if not new_grades:
        print('There are no new grades')
    else:      
        with new_grade_file:
            with old_grade_file:
                for line in new_grade_file:
                    old_grade_file.write(line) 
        for i in range (0, len(new_grades)):
            grades_string += (new_grades[i])
        print(grades_string)
        mail_handler.handle(grades_string)
        tweeter(grades_string)

    new_grade_file.close()
    old_grade_file.close()
                
def tweeter(grades):
    tweet = '{:s}'.format(grades)
    api.update_status(status=tweet)


checker()