app.py

# Python standard libraries
import json
import os
from datetime import date

# Third-party libraries
from flask import Flask, redirect, request, url_for, render_template
from oauthlib.oauth2 import WebApplicationClient
import requests

'''
grades is indexed this way: grades[Branch][Year]
grades[Branch][Year] -> Python list of csv strings

note: this could be obsolete if lot of records are there

TODO: Query from db instead of reading from file into memory
'''
# Load grades into memory
grades = [[None, None, None, None, None], [None, None, None, None, None]]

grades[0][0] = open('./cse19.csv').readlines()
grades[0][1] = open('./cse18.csv').readlines()
grades[0][2] = open('./cse17.csv').readlines()
grades[0][3] = open('./cse16.csv').readlines()
grades[0][3] = open('./cse15.csv').readlines()
grades[1][0] = open('./ece19.csv').readlines()
grades[1][1] = open('./ece18.csv').readlines()
grades[1][2] = open('./ece17.csv').readlines()
grades[1][3] = open('./ece16.csv').readlines()
grades[1][3] = open('./ece15.csv').readlines()

supp = open('./supplementary.csv').readlines()

supplementary = {}

for row in supp:
    roll_col = 0
    sub_col = 1
    grade_col = 2
    fields = row.strip().split(',')
    if fields[roll_col].strip() in supplementary.keys():
        supplementary[fields[roll_col]].append((fields[sub_col], fields[grade_col]))
    else:
        supplementary[fields[roll_col]] = [(fields[sub_col], fields[grade_col])]

def fetch_results(branch, year, email):
    '''
    Input format:
    branch: String (CSE|ECE)
    year: int (19|18|17|16)
    email: String (college given email address)

    Output:
    results: Dict (with sub code as key and grade as value)
    Also, passed, failed are part of results
    '''
    results = {}
    br = -1

    today = date.today()
    yr = today.year%100
    if today.month >= 6:
        yr-=1
    yr -= year
    email_col = 0 # this has to be manually updated according to the dataset
    roll_col = 1
    name_col = 2
    sub_start_id = 3 # this is where the grades start
    if branch == 'C':
        #  grades[0]
        br = 0
    else:
        #  grades[1]
        br = 1
    header = grades[br][yr][0].strip().split(',') # 0th row is not required
    for row in grades[br][yr]:
        fields = row.strip().split(',')
        if fields[email_col].strip() == email:
            if fields[roll_col].strip().upper() != user['rollno'].upper():
                print('Error: Roll Number doesn\'t match')
                break
            user['name'] = fields[name_col]
            for i in range(sub_start_id, len(header)):
                results[header[i]] = fields[i].strip()
            return results

    return results

def fetch_supplementary(rollno):
    supplementary_results = {}
    if rollno in supplementary.keys():
        for t in supplementary[rollno]:
            supplementary_results[t[0]] = t[1]

    return supplementary_results

# Configuration
GOOGLE_CLIENT_ID = os.environ.get("GOOGLE_CLIENT_ID")
GOOGLE_CLIENT_SECRET = os.environ.get("GOOGLE_CLIENT_SECRET", None)
print(GOOGLE_CLIENT_ID)
print(GOOGLE_CLIENT_SECRET)
GOOGLE_DISCOVERY_URL = (
    "https://accounts.google.com/.well-known/openid-configuration"
)

# Flask app setup
app = Flask(__name__)
app.secret_key = os.environ.get("SECRET_KEY") or os.urandom(24)

# OAuth 2 client setup
client = WebApplicationClient(GOOGLE_CLIENT_ID)

# To check if somebody is logged in or not
logged_in = False
user = {
    'name': '',
    'rollno': '',
    'email': '',
    'branch': '',
}

@app.route('/')
def index():
    return render_template('home.html', logged_in=logged_in, user=user)

def get_google_provider_cfg():
    return requests.get(GOOGLE_DISCOVERY_URL).json()

@app.route('/login')
def login():
    # Find out what URL to hit for Google login
    google_provider_cfg = get_google_provider_cfg()
    authorization_endpoint = google_provider_cfg["authorization_endpoint"]
    # Use library to construct the request for Google login and provide
    # scopes that let you retrieve user's profile from Google
    request_uri = client.prepare_request_uri(
        authorization_endpoint,
        redirect_uri=request.base_url + "/callback",
        scope=["openid", "email", "profile"],
    )
    return redirect(request_uri)

@app.route('/login/callback')
def callback():
    code = request.args.get('code')
    google_provider_cfg = get_google_provider_cfg()
    token_endpoint = google_provider_cfg['token_endpoint']
    token_url, headers, body = client.prepare_token_request(
        token_endpoint,
        authorization_endpoint=request.url,
        redirect_url=request.base_url,
        code=code
    )
    token_response = requests.post(
        token_url,
        headers=headers,
        data=body,
        auth=(GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET),
    )

    client.parse_request_body_response(json.dumps(token_response.json()))

    userinfo_endpoint = google_provider_cfg['userinfo_endpoint']
    uri, headers, body = client.add_token(userinfo_endpoint)
    userinfo_response = requests.get(uri, headers=headers, data=body)
    if userinfo_response.json().get('email_verified'):
        unique_id = userinfo_response.json()['sub']
        email = userinfo_response.json()['email']
        name = userinfo_response.json()['name']
    else:
        return "User email not verified", 400

    global logged_in, user
    logged_in = True
    user['name'] = name
    user['email'] = email
    if email.split('@')[0][-1] == 'c':
        user['branch'] = 'CSE'
    else:
        user['branch'] = 'ECE'
    front, rear = user['email'].split('@')
    email2roll = open('./email_roll.csv').readlines()
    for item in email2roll:
        em, rno = item.split(',')
        if em == user['email']:
            user['rollno'] = rno.strip().upper()
            break

    if user['rollno'] == '':
        # means they logged in from some other mail id
        return (
            '<h2>Please login with your institue mail id</h2>'
            '<p>If you did login with your institue mail id, you must be a faculty and this portal is for students. If you think there is some problem and your results are missing, please contact the class coordinator or faculty advisor or member of Web Dev-IIITT</p>'
            '<a href="/logout" class="btn btn-primary">Logout</a>'
        )
    return redirect(url_for('index'))

@app.route('/getresults')
def getresults():
    if logged_in:
        year = int(user['rollno'][3:5])
        branch = user['rollno'][0].upper()
        results = fetch_results(branch.upper(), year, user['email'])
        if (len(results) == 0):
            return (
                '<h2>Error has occurred. Please contact the class coordinator</h2>'
                '<h4>Your results were not found</h4>'
                '<a href="/">Click here to go to home page</a>'
                '<a href="/logout" class="btn btn-primary">Click here to Logout</a>'
            )
        return render_template('results.html', user=user, results=results)
    else:
        return redirect(url_for('index'))

@app.route('/getsupplementary')
def getsupplementary():
    if logged_in:
        if user['rollno'] == '':
            return (
                '<h2>Error has occurred. Please contact the class coordinator</h2>'
                '<h4>Your results were not found</h4>'
                '<a href="/">Click here to go to home page</a>'
                '<a href="/logout" class="btn btn-primary">Click here to Logout</a>'
            )
        results = fetch_supplementary(user['rollno'])
        if len(results) == 0:
            return (
                '<h1>No results</h1>'
                '<p>If you think there is some problem and your results are missing, please contact the class coordinator or faculty advisor</p>'
                '<a href="/">Click here to go to home page</a>'
                '<a href="/logout" class="btn btn-primary">Click here to Logout</a>'
            )
        return render_template('results.html', user=user, results=results)
    else:
        return redirect(url_for('index'))

@app.route('/logout')
def logout():
    global logged_in, user
    for field in user:
        user[field] = ''
    logged_in = False

    return redirect(url_for('index'))

if __name__ == "__main__":
    app.run()