app.py

import os
from functools import wraps
from flask import Flask, render_template, send_file, request, session, redirect, url_for

from user_database import CITIES, MONTHS, data, get_city_temperature, get_city_humidity
from user_database import db_session as db_session
from charts import get_city_image, get_main_image

app = Flask(__name__)


@app.route('/')
def main():
    """Entry point; the view for the main page"""
    cities = [(record.city_id, record.city_name) for record in data]
    return render_template('main.html', cities=cities)


@app.route('/main.png')
def main_plot():
    """The view for rendering the scatter chart"""
    img = get_main_image()
    return send_file(img, mimetype='image/png', cache_timeout=0)


@app.route('/login/<int:city_id>',  methods=["GET", "POST"])
def login(city_id):
    """The view for the login page"""
    city_record = data.get(city_id)
    try:
        error = ''
        if request.method == "POST":
            attempted_username = request.form['username']
            attempted_password = request.form['password']
            if attempted_username == 'admin' and attempted_password == os.environ['USER_PASSWORD']:
                session['logged_in'] = True
                session['username'] = request.form['username']
                return redirect(url_for('edit_database', city_id=city_id))
            else:
                print('invalid credentials')
                error = 'Invalid credentials. Please, try again.'
        return render_template('login.html', error=error, city_name=city_record.city_name, city_id=city_id)
    except Exception as e:
        return render_template('login.html', error=str(e), city_name=city_record.city_name, city_id=city_id)


def login_required(f):
    @wraps(f)
    def wrap(*args, **kwargs):
        """login session"""
        if 'logged_in' in session:
            return f(*args, **kwargs)
        else:
            pass
        return redirect(url_for('login'))
    return wrap


app.secret_key = os.environ['FLASK_WEB_APP_KEY']


@app.route('/city/<int:city_id>')
def city(city_id):
    """Views for the city details"""
    city_record = data.get(city_id)
    return render_template('city.html', city_name=city_record.city_name, city_id=city_id,
                           city_climate=city_record.city_climate)


@app.route('/city<int:city_id>.png')
def city_plot(city_id):
    """Views for rendering city specific charts"""
    img = get_city_image(city_id)
    return send_file(img, mimetype='image/png', cache_timeout=0,)


@app.route('/edit/<int:city_id>', methods=["GET", "POST"])
@login_required
def edit_database(city_id):
    """Views for editing city specific data"""
    month_temperature = []
    month_humidity = []
    city_record = data.get(city_id)
    meteo = [get_city_temperature(city_record), get_city_humidity(city_record)]
    try:
        if request.method == "POST":
            # Get data from the form
            for i in range(12):
                # We ought to validate the input data, but this is a toy example so we don't really care
                month_temperature.append(float(request.form[f'temperature{i}']))
                month_humidity.append(int(request.form[f'humidity{i}']))

            # Database update
            for i, month in enumerate(city_record.city_meteo_data):
                month.average_temperature = month_temperature[i]
                month.average_humidity = month_humidity[i]

            db_session.commit()
            return redirect(url_for('main', city_id=city_id))
        else:
            return render_template('edit.html', city_name=city_record.city_name, city_id=city_id, months=MONTHS,
                                   meteo=meteo)
    except Exception as error:
        return render_template('edit.html', city_name=city_record.city_name, city_id=city_id, months=MONTHS,
                               meteo=meteo, error=error)


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