feat(users): implement fetch self / user, open dm

src/routes/users/open_dm.rs

@@ -1,10 +1,31 @@
-use revolt_quark::{Error, Result};
+//! Open a direct message with another user
+
+use revolt_quark::{Error, Result, Ref, models::{User, Channel}, Database, perms, UserPermission};
 
 use mongodb::bson::doc;
-use rocket::serde::json::Value;
+use rocket::{State, serde::json::Json};
 use ulid::Ulid;
 
 #[get("/<target>/dm")]
-pub async fn req(/*user: UserRef, target: Ref*/ target: String) -> Result<Value> {
-    todo!()
+pub async fn req(db: &State<Database>, user: User, target: Ref) -> Result<Json<Channel>> {
+    let target = target.as_user(db).await?;
+
+    if let Ok(channel) = db.find_direct_message_channel(&user.id, &target.id).await {
+        Ok(Json(channel))
+    } else if perms(&user).user(&target).calc_user(db).await.get_send_message() {
+        let new_channel = Channel::DirectMessage {
+            id: Ulid::new().to_string(),
+            active: false,
+            recipients: vec! [
+                user.id.clone(),
+                target.id.clone()
+            ],
+            last_message_id: None,
+        };
+
+        db.insert_channel(&new_channel).await?;
+        Ok(Json(new_channel))
+    } else {
+        Error::from_permission(UserPermission::SendMessage)
+    }
 }