app.py

import os
from flask import Flask, render_template, url_for, redirect, jsonify, request
from flask_sqlalchemy import SQLAlchemy
from flask_login import UserMixin, login_user, LoginManager, login_required, logout_user, current_user
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField
from wtforms.validators import InputRequired, Length, ValidationError
from flask_bcrypt import Bcrypt
from datetime import datetime
import pytz
import tzlocal
from dotenv import load_dotenv

# Load environment variables from .env file
load_dotenv()

app = Flask(__name__)

# Retrieve configurations from environment variables
app.config['SQLALCHEMY_DATABASE_URI'] = os.getenv('DATABASE_URL', 'sqlite:///default.db')
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SECRET_KEY'] = os.getenv('SECRET_KEY', 'HeadStarterHackathonProject')


db = SQLAlchemy(app)
bcrypt = Bcrypt(app)

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))


class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), nullable=False, unique=True)
    password = db.Column(db.String(80), nullable=False)


class RegisterForm(FlaskForm):
    username = StringField(validators=[
                           InputRequired(), Length(min=4, max=20)], render_kw={"placeholder": "Username"})

    password = PasswordField(validators=[
                             InputRequired(), Length(min=8, max=20)], render_kw={"placeholder": "Password"})

    submit = SubmitField('Register')

    def validate_username(self, username):
        existing_user_username = User.query.filter_by(
            username=username.data).first()
        if existing_user_username:
            raise ValidationError(
                'That username already exists. Please choose a different one.')


class LoginForm(FlaskForm):
    username = StringField(validators=[
                           InputRequired(), Length(min=4, max=20)], render_kw={"placeholder": "Username"})

    password = PasswordField(validators=[
                             InputRequired(), Length(min=8, max=20)], render_kw={"placeholder": "Password"})

    submit = SubmitField('Login')


@app.route('/')
def home():
    return render_template('index.html')


@app.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.username.data).first()
        if user:
            if bcrypt.check_password_hash(user.password, form.password.data):
                login_user(user)
                return redirect(url_for('dashboard'))
    return render_template('login.html', form=form)


@app.route('/dashboard', methods=['GET', 'POST'])
@login_required
def dashboard():
    return render_template('dashboard.html')


@app.route('/logout', methods=['GET', 'POST'])
@login_required
def logout():
    logout_user()
    return redirect(url_for('login'))


@app.route('/register', methods=['GET', 'POST'])
def register():
    form = RegisterForm()

    if form.validate_on_submit():
        hashed_password = bcrypt.generate_password_hash(form.password.data)
        new_user = User(username=form.username.data, password=hashed_password)
        db.session.add(new_user)
        db.session.commit()
        return redirect(url_for('login'))

    return render_template('register.html', form=form)


@app.route('/sync_duration', methods=['POST'])
def sync_duration():
    data = request.json
    date_str = data.get('date')
    time_str = data.get('time')
    target_timezone_str = data.get('targetTimezone')

    if len(time_str) == 5:
        time_str += ":00"

    local_tz = tzlocal.get_localzone()
    local_now = datetime.now(local_tz)

    try:
        target_datetime = datetime.strptime(
            f"{date_str} {time_str}", "%Y-%m-%d %H:%M:%S")
        target_tz = pytz.timezone(target_timezone_str)
        target_time = target_tz.localize(target_datetime, is_dst=None)

        target_time_utc = target_time.astimezone(pytz.utc)

        current_utc_time = datetime.now(pytz.utc)
        local_time_at_target = target_time_utc.astimezone(local_tz)
        local_time_str = local_time_at_target.strftime("%Y-%m-%d %H:%M:%S")

        time_difference = target_time_utc - current_utc_time
        total_seconds = int(time_difference.total_seconds())
        hours, remainder = divmod(total_seconds, 3600)
        minutes, seconds = divmod(remainder, 60)

        return jsonify({
            'hours': hours,
            'minutes': minutes,
            'seconds': seconds,
            'local_time_at_target': local_time_str
        })
    except Exception as e:
        return jsonify({'error': str(e)}), 500