activitypub-federation-rust/examples/federation-actix/instance.rs

use crate::{
    error::Error,
    generate_object_id,
    objects::{
        note::MyPost,
        person::{MyUser, PersonAcceptedActivities},
    },
};
use activitypub_federation::{
    core::{
        actix::inbox::receive_activity,
        object_id::ObjectId,
        signatures::generate_actor_keypair,
    },
    deser::context::WithContext,
    request_data::{ApubContext, ApubMiddleware, RequestData},
    traits::ApubObject,
    FederationSettings,
    InstanceConfig,
    UrlVerifier,
    APUB_JSON_CONTENT_TYPE,
};
use actix_web::{web, App, HttpRequest, HttpResponse, HttpServer};
use async_trait::async_trait;
use reqwest::Client;
use std::sync::{Arc, Mutex};
use tokio::task;
use url::Url;

pub type DatabaseHandle = Arc<Database>;

/// Our "database" which contains all known posts users (local and federated)
pub struct Database {
    pub users: Mutex<Vec<MyUser>>,
    pub posts: Mutex<Vec<MyPost>>,
}

/// Use this to store your federation blocklist, or a database connection needed to retrieve it.
#[derive(Clone)]
struct MyUrlVerifier();

#[async_trait]
impl UrlVerifier for MyUrlVerifier {
    async fn verify(&self, url: &Url) -> Result<(), &'static str> {
        if url.domain() == Some("malicious.com") {
            Err("malicious domain")
        } else {
            Ok(())
        }
    }
}

impl Database {
    pub fn new(hostname: String) -> Result<ApubContext<DatabaseHandle>, Error> {
        let settings = FederationSettings::builder()
            .debug(true)
            .url_verifier(Box::new(MyUrlVerifier()))
            .build()?;
        let local_instance =
            InstanceConfig::new(hostname.clone(), Client::default().into(), settings);
        let local_user = MyUser::new(generate_object_id(&hostname)?, generate_actor_keypair()?);
        let instance = Arc::new(Database {
            users: Mutex::new(vec![local_user]),
            posts: Mutex::new(vec![]),
        });
        Ok(ApubContext::new(instance, local_instance))
    }

    pub fn local_user(&self) -> MyUser {
        self.users.lock().unwrap().first().cloned().unwrap()
    }

    pub fn listen(data: &ApubContext<DatabaseHandle>) -> Result<(), Error> {
        let hostname = data.local_instance().hostname();
        let data = data.clone();
        let server = HttpServer::new(move || {
            App::new()
                .wrap(ApubMiddleware::new(data.clone()))
                .route("/objects/{user_name}", web::get().to(http_get_user))
                .service(
                    web::scope("")
                        // Just a single, global inbox for simplicity
                        .route("/inbox", web::post().to(http_post_user_inbox)),
                )
        })
        .bind(hostname)?
        .run();
        task::spawn(server);
        Ok(())
    }
}

/// Handles requests to fetch user json over HTTP
async fn http_get_user(
    request: HttpRequest,
    data: RequestData<DatabaseHandle>,
) -> Result<HttpResponse, Error> {
    let hostname: String = data.local_instance().hostname().to_string();
    let request_url = format!("http://{}{}", hostname, &request.uri().to_string());
    let url = Url::parse(&request_url)?;
    let user = ObjectId::<MyUser>::new(url)
        .dereference_local(&data)
        .await?
        .into_apub(&data)
        .await?;

    Ok(HttpResponse::Ok()
        .content_type(APUB_JSON_CONTENT_TYPE)
        .json(WithContext::new_default(user)))
}

/// Handles messages received in user inbox
async fn http_post_user_inbox(
    request: HttpRequest,
    payload: String,
    data: RequestData<DatabaseHandle>,
) -> Result<HttpResponse, Error> {
    let activity = serde_json::from_str(&payload)?;
    receive_activity::<WithContext<PersonAcceptedActivities>, MyUser, DatabaseHandle>(
        request, activity, &data,
    )
    .await
}