example-spa-elm-app/backend/src/main.rs

use actix::prelude::*;
use actix_files::Files;
use actix_web::{web, App, Error, HttpRequest, HttpResponse, HttpServer, Responder};
use actix_web_actors::ws;
use chrono::Local;
use log::info;
use serde::{Deserialize, Serialize};
use std::{fs, time::Duration};

mod landing;

#[derive(Serialize, Debug)]
pub enum DownMsg {
    Landing(landing::DownMsg),
}

#[derive(Deserialize, Debug)]
enum UpMsg {
    Landing(landing::UpMsg),
}

pub struct MyWebSocket;

impl Actor for MyWebSocket {
    type Context = ws::WebsocketContext<Self>;

    fn started(&mut self, ctx: &mut Self::Context) {
        info!("WebSocket actor started");
        ctx.run_interval(Duration::from_secs(1), |_, ctx| {
            let current_time = Local::now().format("%H:%M:%S").to_string();
            let message = DownMsg::Landing(landing::DownMsg::TimeUpdate(current_time));

            if let Ok(json_message) = serde_json::to_string(&message) {
                ctx.text(json_message);
            }
        });
    }
}

impl StreamHandler<Result<ws::Message, ws::ProtocolError>> for MyWebSocket {
    fn handle(
        &mut self,
        msg: Result<ws::Message, ws::ProtocolError>,
        ctx: &mut ws::WebsocketContext<Self>,
    ) {
        match msg {
            Ok(ws::Message::Text(text)) => {
                if let Ok(up_msg) = serde_json::from_str::<UpMsg>(&text) {
                    match up_msg {
                        UpMsg::Landing(msg) => 
                            landing::msg_handler(msg, self, ctx),
                    }
                }
            }
            Ok(ws::Message::Ping(msg)) => {
                ctx.pong(&msg);
            }
            _ => {}
        }
    }
}

impl MyWebSocket {
    fn send_down_msg(&self, down_msg: DownMsg, ctx: &mut ws::WebsocketContext<Self>) {
        if let Ok(serialized_msg) = serde_json::to_string(&down_msg) {
            ctx.text(serialized_msg);
        } else {
            log::error!("Failed to serialize DownMsg {:?}", down_msg);
        }
    }
}

async fn websocket_handler(req: HttpRequest, stream: web::Payload) -> Result<HttpResponse, Error> {
    ws::start(MyWebSocket {}, &req, stream)
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    env_logger::init();

    let address = "127.0.0.1";
    let port = std::env::var("EXAMPLE_ELM_APP_PORT")
        .unwrap_or("8080".to_string())
        .parse()
        .unwrap();

    info!("Starting server at http://{}:{}", address, port);

    HttpServer::new(|| {
        App::new()
            .route("/ws/", web::get().to(websocket_handler)) // WebSocket endpoint
            .service(Files::new("/assets", "./public/assets"))
            .service(Files::new("/", "./public").index_file("index.html")) // Serve frontend
            .default_service(web::route().to(|| async {
                let index_html = fs::read_to_string("./public/index.html")
                    .unwrap_or_else(|_| "404 Not Found".to_string());
                HttpResponse::Ok()
                    .content_type("text/html; charset=utf-8")
                    .body(index_html)
            }))
    })
    .bind((address, port))?
    .run()
    .await
}