food-tracker/src/main.rs

use std::sync::{Arc, Mutex};

use axum::{extract::{Path, State}, response::{Html, Redirect}, routing::{get, post}, Router};
use rusqlite::Connection;
use askama::Template;

#[derive(Template)]
#[template(path = "index.html")]
struct IndexTemplate {
    foods: Vec<Food>,
    sum: i32,
}

#[derive(Debug, Clone, PartialEq)]
struct Food {
    id: i32,
   portion: String,
   name: String,
    kc_per_serving: i32,
    target_servings: i32,
    actual_servings: i32,
}

#[tokio::main]
async fn main() {
    let db_connecion_str = "./foods.db".to_string();
    let conn = Connection::open(db_connecion_str).unwrap();
    conn.execute(include_str!("create_tables.sql"), ()).unwrap();
    let conn = Arc::new(Mutex::new(conn));
    
    let app = Router::new().route("/", get(root))
        .route("/increase/{id}", post(increase))
        .route("/decrease/{id}", post(decrease))
        .with_state(conn);

    let listener = tokio::net::TcpListener::bind("0.0.0.0:3001").await.unwrap();
    println!("listening on {}", listener.local_addr().unwrap());
    axum::serve(listener, app).await.unwrap();
}

async fn root(
    State(conn): State<Arc<Mutex<Connection>>>
) -> Html<String> {
    let conn = conn.lock().unwrap();
    let mut stmt = conn.prepare("SELECT id, portion, name, kc_per_serving, target_servings, actual_servings FROM food").unwrap();
    let foods = stmt.query_map((), |row| {
        Ok(Food {
            id: row.get(0).unwrap(),
            portion: row.get(1).unwrap(),
            name: row.get(2).unwrap(),
            kc_per_serving: row.get(3).unwrap(),
            target_servings: row.get(4).unwrap(),
            actual_servings: row.get(5).unwrap(),
        })
    }).unwrap().collect::<Result<_, _>>().unwrap();
    let mut stmt = conn.prepare("SELECT SUM(kc_per_serving * actual_servings) as kc FROM food").unwrap();
    let sum = stmt.query_one((), |row| row.get(0)).unwrap();
    let index = IndexTemplate {foods, sum};
    Html(
        index.render().unwrap()
    )
}

async fn increase(
        State(conn): State<Arc<Mutex<Connection>>>,
        Path(id): Path<i32>
) -> Redirect{
    let conn = conn.lock().unwrap();
    let mut stmt = conn.prepare("UPDATE food SET actual_servings = (SELECT actual_servings FROM food WHERE id = ?1) + 1 WHERE id = ?1").unwrap();
    stmt.execute((id,)).unwrap();
    Redirect::to("/")
}
async fn decrease(
        State(conn): State<Arc<Mutex<Connection>>>,
        Path(id): Path<i32>
) -> Redirect{
    let conn = conn.lock().unwrap();
    let mut stmt = conn.prepare("UPDATE food SET actual_servings = MAX((SELECT actual_servings FROM food WHERE id = ?1) - 1, 0) WHERE id = ?1").unwrap();
    stmt.execute((id,)).unwrap();
    Redirect::to("/")
}