app.py

import requests
import string
import datetime
from flask import Flask, render_template, request, redirect, url_for, flash
from flask_sqlalchemy import SQLAlchemy
from dotenv import load_dotenv
load_dotenv()

OWM_ENDPOINT = "https://api.openweathermap.org/data/2.5/weather"
OWM_FORECAST_ENDPOINT = "https://api.openweathermap.org/data/2.5/forecast"
GEOCODING_API_ENDPOINT = "http://api.openweathermap.org/geo/1.0/direct"
api_key = "1b7327427012cd35c4de782378022165"
app = Flask(__name__)
app.config['DEBUG'] = True
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///weather.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SECRET_KEY'] = 'thisisasecret'
db = SQLAlchemy(app)


class city(db.Model) :
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50),nullable=False)

def get_weather_data(city):
    url = f"http://api.openweathermap.org/data/2.5/weather?q={city}&units=metric&appid=1b7327427012cd35c4de782378022165"
    r = requests.get(url).json()
    return r

@app.route('/')
def index_get():
    cities = city.query.distinct().order_by(city.id.desc()).limit(3).all()
    weather_data = []

    for c in cities:
        r = get_weather_data(c.name)
        weather = {
            'city' : c.name,
            'temperature' : r['main']['temp'],
            'description' : r['weather'][0]['description'],
            'icon' : r['weather'][0]['icon'],
        }
        weather_data.append(weather)

    return render_template('weather.html', weather_data=weather_data)

@app.route("/<city>", methods=["GET", "POST"])
def get_weather(city):
    # Format city name and get current date to display on page
    city_name = string.capwords(city)
    today = datetime.datetime.now()
    current_date = today.strftime("%A, %B %d")

    # Get latitude and longitude for city
    location_params = {
        "q": city_name,
        "appid": api_key,
        "limit": 3,
    }

    location_response = requests.get(GEOCODING_API_ENDPOINT, params=location_params)
    location_data = location_response.json()

    # Prevent IndexError if user entered a city name with no coordinates by redirecting to error page
    if not location_data:
        return redirect(url_for("error"))
    else:
        lat = location_data[0]['lat']
        lon = location_data[0]['lon']

    # Get OpenWeather API data
    weather_params = {
        "lat": lat,
        "lon": lon,
        "appid": api_key,
        "units": "metric",
    }
    weather_response = requests.get(OWM_ENDPOINT, weather_params)
    weather_response.raise_for_status()
    weather_data = weather_response.json()

    # Get current weather data
    current_temp = round(weather_data['main']['temp'])
    current_weather = weather_data['weather'][0]['main']
    min_temp = round(weather_data['main']['temp_min'])
    max_temp = round(weather_data['main']['temp_max'])
    wind_speed = weather_data['wind']['speed']

    # Get five-day weather forecast data
    forecast_response = requests.get(OWM_FORECAST_ENDPOINT, weather_params)
    forecast_data = forecast_response.json()

    # Make lists of temperature and weather description data to show user
    five_day_temp_list = [round(item['main']['temp']) for item in forecast_data['list'] if '12:00:00' in item['dt_txt']]
    five_day_weather_list = [item['weather'][0]['main'] for item in forecast_data['list']
                             if '12:00:00' in item['dt_txt']]

    # Get next four weekdays to show user alongside weather data
    five_day_unformatted = [today, today + datetime.timedelta(days=1), today + datetime.timedelta(days=2),
                            today + datetime.timedelta(days=3), today + datetime.timedelta(days=4)]
    five_day_dates_list = [date.strftime("%a") for date in five_day_unformatted]

    return render_template("city.html", city_name=city_name, current_date=current_date, current_temp=current_temp,
                           current_weather=current_weather, min_temp=min_temp, max_temp=max_temp, wind_speed=wind_speed,
                           five_day_temp_list=five_day_temp_list, five_day_weather_list=five_day_weather_list,
                           five_day_dates_list=five_day_dates_list)

@app.route('/', methods=["POST"])
def index_post():
    err_msg = ''
    new_city = request.form.get('city')
    new_city = new_city.lower()
    new_city = string.capwords(new_city)
    if new_city:
        existing_city = city.query.filter_by(name=new_city).first()
        
        if existing_city:
            db.session.delete(existing_city)
            db.session.commit()
        new_city_data = get_weather_data(new_city)
        if new_city_data['cod'] == 200:
            new_city_obj = city(name=new_city)

            db.session.add(new_city_obj)
            db.session.commit()
        else:
            return redirect(url_for("error"))

    if err_msg:
         return redirect(url_for("error"))
    else:
        #flash('City added successfully!', 'success')
        if request.method == "POST":
            c = request.form.get("search")
            return redirect(url_for("get_weather", city=new_city))
        else:
            return redirect(url_for('index_get'))

@app.route('/delete/<name>')
def delete_city( name ):
    c = city.query.filter_by(name=name).first()
    db.session.delete(c)
    db.session.commit()

    flash(f'Successfully deleted { c.name }!', 'success')
    return redirect(url_for('index_get'))


@app.route("/error")
def error():
    return render_template("error.html")