From 9d37408535481b39b7c60825b07e88c2b4088019 Mon Sep 17 00:00:00 2001
From: Kitaiti Makoto <KitaitiMakoto@gmail.com>
Date: Sun, 31 Jan 2021 22:56:17 +0900
Subject: [PATCH] Define RemoteFetchActor

---
 plume-models/src/lib.rs                |   1 +
 plume-models/src/remote_fetch_actor.rs | 103 +++++++++++++++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 plume-models/src/remote_fetch_actor.rs

diff --git a/plume-models/src/lib.rs b/plume-models/src/lib.rs
index 8bfb2002..a3d10755 100755
--- a/plume-models/src/lib.rs
+++ b/plume-models/src/lib.rs
@@ -356,6 +356,7 @@ pub mod password_reset_requests;
 pub mod plume_rocket;
 pub mod post_authors;
 pub mod posts;
+pub mod remote_fetch_actor;
 pub mod reshares;
 pub mod safe_string;
 #[allow(unused_imports)]
diff --git a/plume-models/src/remote_fetch_actor.rs b/plume-models/src/remote_fetch_actor.rs
new file mode 100644
index 00000000..49163404
--- /dev/null
+++ b/plume-models/src/remote_fetch_actor.rs
@@ -0,0 +1,103 @@
+use crate::{
+    db_conn::{DbConn, DbPool},
+    follows,
+    posts::{LicensedArticle, Post},
+    users::{User, UserEvent},
+    ACTOR_SYS, CONFIG, USER_CHAN,
+};
+use activitypub::activity::Create;
+use plume_common::activity_pub::inbox::FromId;
+use riker::actors::{Actor, ActorFactoryArgs, ActorRefFactory, Context, Sender, Subscribe, Tell};
+use std::sync::Arc;
+use tracing::{error, info, warn};
+
+pub struct RemoteFetchActor {
+    conn: DbPool,
+}
+
+impl RemoteFetchActor {
+    pub fn init(conn: DbPool) {
+        ACTOR_SYS
+            .actor_of_args::<RemoteFetchActor, _>("remote-fetch", conn)
+            .expect("Failed to initialize remote fetch actor");
+    }
+}
+
+impl Actor for RemoteFetchActor {
+    type Msg = UserEvent;
+
+    fn pre_start(&mut self, ctx: &Context<Self::Msg>) {
+        USER_CHAN.tell(
+            Subscribe {
+                actor: Box::new(ctx.myself()),
+                topic: "*".into(),
+            },
+            None,
+        )
+    }
+
+    fn recv(&mut self, _ctx: &Context<Self::Msg>, msg: Self::Msg, _sender: Sender) {
+        use UserEvent::*;
+
+        match msg {
+            RemoteUserFound(user) => match self.conn.get() {
+                Ok(conn) => {
+                    let conn = DbConn(conn);
+                    fetch_and_cache_articles(&user, &conn);
+                    fetch_and_cache_followers(&user, &conn);
+                    if user.needs_update() {
+                        fetch_and_cache_user(&user, &conn);
+                    }
+                }
+                _ => {
+                    error!("Failed to get database connection");
+                }
+            },
+        }
+    }
+}
+
+impl ActorFactoryArgs<DbPool> for RemoteFetchActor {
+    fn create_args(conn: DbPool) -> Self {
+        Self { conn }
+    }
+}
+
+fn fetch_and_cache_articles(user: &Arc<User>, conn: &DbConn) {
+    for create_act in user
+        .fetch_outbox::<Create>()
+        .expect("Remote user: outbox couldn't be fetched")
+    {
+        match create_act.create_props.object_object::<LicensedArticle>() {
+            Ok(article) => {
+                Post::from_activity(conn, article)
+                    .expect("Article from remote user couldn't be saved");
+                info!("Fetched article from remote user");
+            }
+            Err(e) => warn!("Error while fetching articles in background: {:?}", e),
+        }
+    }
+}
+
+fn fetch_and_cache_followers(user: &Arc<User>, conn: &DbConn) {
+    for user_id in user
+        .fetch_followers_ids()
+        .expect("Remote user: fetching followers error")
+    {
+        let follower = User::from_id(conn, &user_id, None, CONFIG.proxy())
+            .expect("user::details: Couldn't fetch follower");
+        follows::Follow::insert(
+            conn,
+            follows::NewFollow {
+                follower_id: follower.id,
+                following_id: user.id,
+                ap_url: String::new(),
+            },
+        )
+        .expect("Couldn't save follower for remote user");
+    }
+}
+
+fn fetch_and_cache_user(user: &Arc<User>, conn: &DbConn) {
+    user.refetch(conn).expect("Couldn't update user info");
+}