Add onboarding and FromRequest for User.

src/routes/onboard/complete.rs

@@ -0,0 +1,52 @@
+use mongodb::options::{Collation, FindOneOptions};
+use crate::util::result::{Error, Result};
+use serde::{Deserialize, Serialize};
+use crate::database::entities::User;
+use crate::database::get_collection;
+use rocket_contrib::json::Json;
+use rauth::auth::Session;
+use validator::Validate;
+use mongodb::bson::doc;
+
+#[derive(Validate, Serialize, Deserialize)]
+pub struct Data {
+    #[validate(length(min = 2, max = 32))]
+    username: String
+}
+
+#[post("/complete", data = "<data>")]
+pub async fn req(session: Session, user: Option<User>, data: Json<Data>) -> Result<()> {
+    if user.is_some() {
+        Err(Error::AlreadyOnboarded)?
+    }
+    
+    data.validate()
+        .map_err(|error| Error::FailedValidation { error })?;
+
+    let col = get_collection("users");
+    if col.find_one(
+        doc! {
+            "username": &data.username
+        },
+        FindOneOptions::builder()
+            .collation(Collation::builder().locale("en").strength(2).build())
+            .build()
+    )
+    .await
+    .map_err(|_| Error::DatabaseError { operation: "find_one", with: "user" })?
+    .is_some() {
+        Err(Error::UsernameTaken)?
+    }
+
+    col.insert_one(
+        doc! {
+            "_id": session.user_id,
+            "username": &data.username
+        },
+        None
+    )
+    .await
+    .map_err(|_| Error::DatabaseError { operation: "insert_one", with: "user" })?;
+
+    Ok(())
+}