use actix_web::{web::Json, App, HttpRequest, HttpServer, Responder};
use serde::Serialize;

#[derive(Serialize)]
struct EchoHeader {
    name: String,
    value: String,
}

#[derive(Serialize)]
struct EchoResponse {
    method: String,
    path: String,
    host: String,
    headers: Vec<EchoHeader>,
}

impl EchoResponse {
    fn new(req: &HttpRequest) -> Self {
        let req_uri = req.uri();
        let headers = req
            .headers()
            .iter()
            .map(|(header_name, header_value)| EchoHeader {
                name: header_name.to_string(),
                value: header_value.to_str().unwrap_or("ERROR").to_string(),
            })
            .collect::<Vec<EchoHeader>>();
        EchoResponse {
            method: req.method().to_string(),
            path: req_uri.path().to_string(),
            host: req_uri.host().unwrap_or("").to_string(),
            headers,
        }
    }
}

async fn echo_request(request: HttpRequest) -> actix_web::Result<impl Responder> {
    let echo = EchoResponse::new(&request);
    Ok(Json(echo))
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| App::new().default_service(actix_web::web::route().to(echo_request)))
        .bind(("0.0.0.0", 8080))?
        .run()
        .await
}