* OpenWeatherMap Client

build a tiny Rust program that collects weather data for a collection of POI of
mine and writes it into a SQLite database

** initial prompt

#+begin_quote
please parse OpenWeatherAPI response in rust
#+end_quote

Accidently I used not the full name which should bei *openWeatherMap*

Response:

#+begin_src rust
  extern crate reqwest;
extern crate serde;
extern crate serde_json;

use serde::Deserialize;
use std::error::Error;

#[derive(Deserialize, Debug)]
struct WeatherResponse {
    main: Main,
    weather: Vec<Weather>,
}

#[derive(Deserialize, Debug)]
struct Main {
    temp: f64,
    pressure: f64,
    humidity: f64,
    temp_min: f64,
    temp_max: f64,
}

#[derive(Deserialize, Debug)]
struct Weather {
    id: u32,
    main: String,
    description: String,
    icon: String,
}

fn get_weather(city: &str) -> Result<(), Box<dyn Error>> {
    let url = format!(
        "https://api.openweathermap.org/data/2.5/weather?q={}&appid={API_KEY}",
        city, API_KEY=API_KEY
    );

    let mut resp = reqwest::get(&url)?;
    let weather: WeatherResponse = resp.json()?;

    println!("Temperature: {}°F", weather.main.temp);
    println!("Pressure: {} hPa", weather.main.pressure);
    println!("Humidity: {}%", weather.main.humidity);
    println!("Minimum temperature: {}°F", weather.main.temp_min);
    println!("Maximum temperature: {}°F", weather.main.temp_max);
    for w in weather.weather {
        println!("{}: {}", w.main, w.description);
    }

    Ok(())
}
#+end_src

#+begin_quote
This example uses the reqwest crate to make an HTTP request to the
OpenWeatherAPI and the serde and serde_json crates to parse the JSON response.

The WeatherResponse struct represents the top-level JSON object in the response,
with fields for the main weather information and a list of weather conditions.
The Main struct represents the main weather information, with fields for
temperature, pressure, humidity, and minimum and maximum temperature. The
Weather struct represents a single weather condition, with fields for the
condition ID, main condition, description, and icon.

The get_weather function makes a request to the OpenWeatherAPI for the given
city and parses the response into a WeatherResponse struct. It then prints out
the main weather information and the list of weather conditions.

You'll need to replace API_KEY with your own API key, which you can get by
signing up for a free account at https://home.openweathermap.org/users/sign_up.
#+end_quote

See how it even shows me where to get and put the API key required for the HTTP request

** Ask for Async and SQLITE

#+begin_quote
please use async and send the result to sqlite database
#+end_quote

Response:

#+begin_quote
Sure! Here's an example of how you can use async and send the result to a SQLite
database in Rust:

First, you'll need to add the following dependencies to your Cargo.toml file:
#+end_quote

#+begin_src toml
[dependencies]
async-std = { version = "1", features = ["attributes"] }
sqlx = { version = "0.4", features = ["macros"] }
#+end_src

#+begin_src rust

  use async_std::task;
use sqlx::{query, query_as, Executor};

#[derive(Deserialize, Insertable)]
#[table_name = "weather"]
struct WeatherData {
    city: String,
    temperature: f64,
    pressure: f64,
    humidity: f64,
    temp_min: f64,
    temp_max: f64,
    main: String,
    description: String,
}

async fn get_weather_async(city: &str, db: &mut sqlx::SqliteConnection) -> Result<(), Box<dyn std::error::Error>> {
    let url = format!(
        "https://api.openweathermap.org/data/2.5/weather?q={}&appid={API_KEY}",
        city, API_KEY=API_KEY
    );

    let resp: WeatherResponse = reqwest::get(&url)
        .await?
        .json()
        .await?;

    let weather_data = WeatherData {
        city: city.to_string(),
        temperature: resp.main.temp,
        pressure: resp.main.pressure,
        humidity: resp.main.humidity,
        temp_min: resp.main.temp_min,
        temp_max: resp.main.temp_max,
        main: resp.weather[0].main,
        description: resp.weather[0].description,
    };

    query!(
        "INSERT INTO weather (city, temperature, pressure, humidity, temp_min, temp_max, main, description) VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
        weather_data.city,
        weather_data.temperature,
        weather_data.pressure,
        weather_data.humidity,
        weather_data.temp_min,
        weather_data.temp_max,
        weather_data.main,
        weather_data.description
    )
    .execute(db)
    .await?;

    Ok(())
}

#[async_std::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut db = sqlx::SqliteConnection::connect("sqlite://./weather.db").await?;

    task::spawn(async {
        get_weather_async("New York", &mut db).await.unwrap();
    });

    task::spawn(async {
        get_weather_async("London", &mut db).await.unwrap();
    });

    task::spawn(async {
       

#+end_src

The last part of the response is snipped here again. I assume, that the number
of token for my free account is reached here. We can probably work around that
by requesting more concise parts of the code.

** I dont want to use the 'city' parameter

#+begin_quote
can I use lat,lon coordinates instead of the city parameter?
#+end_quote

Response:

#+begin_quote
Yes, you can use latitude and longitude coordinates instead of the city
parameter to get the weather information for a specific location from the
OpenWeatherAPI.

To do this, you'll need to modify the API request URL to include the lat and lon parameters. For example:
#+end_quote

#+begin_src rust
  let url = format!(
    "https://api.openweathermap.org/data/2.5/weather?lat={lat}&lon={lon}&appid={API_KEY}",
    lat=lat, lon=lon, API_KEY=API_KEY
);

#+end_src

#+begin_quote
Here, lat and lon are the latitude and longitude coordinates of the location you
want to get the weather information for. Make sure to replace API_KEY with your
own API key, which you can get by signing up for a free account at
https://home.openweathermap.org/users/sign_up.

You can then use the modified URL to make the API request and parse the response
as shown in the previous example.
#+end_quote

I like how it refers to the previous output and tells me which part to update.