feat: add users endpoint and add me and uuid under it

Adds a users endpoint that returns all users on the server, will require instance permissions in future.
Place previous user requests under users to avoid having multiple endpoints.

src/api/v1/users/mod.rs

@@ -0,0 +1,77 @@
+use actix_web::{error, post, web, Error, HttpResponse, Scope};
+use futures::StreamExt;
+use log::error;
+use serde::{Deserialize, Serialize};
+use sqlx::prelude::FromRow;
+use crate::{Data, api::v1::auth::check_access_token};
+
+mod me;
+mod uuid;
+
+#[derive(Deserialize)]
+struct Request {
+    access_token: String,
+    start: i32,
+    amount: i32,
+}
+
+#[derive(Serialize, FromRow)]
+struct Response {
+    uuid: String,
+    username: String,
+    display_name: Option<String>,
+    email: String,
+}
+
+const MAX_SIZE: usize = 262_144;
+
+pub fn web() -> Scope {
+    web::scope("/users")
+        .service(res)
+        .service(me::res)
+        .service(uuid::res)
+}
+
+#[post("")]
+pub async fn res(
+    mut payload: web::Payload,
+    data: web::Data<Data>,
+) -> Result<HttpResponse, Error> {
+    let mut body = web::BytesMut::new();
+    while let Some(chunk) = payload.next().await {
+        let chunk = chunk?;
+        // limit max size of in-memory payload
+        if (body.len() + chunk.len()) > MAX_SIZE {
+            return Err(error::ErrorBadRequest("overflow"));
+        }
+        body.extend_from_slice(&chunk);
+    }
+
+    let request = serde_json::from_slice::<Request>(&body)?;
+
+    if request.amount > 100 {
+        return Ok(HttpResponse::BadRequest().finish())
+    }
+
+    let authorized = check_access_token(request.access_token, &data.pool).await;
+
+    if let Err(error) = authorized {
+        return Ok(error);
+    }
+
+    let row = sqlx::query_as("SELECT CAST(uuid AS VARCHAR), username, display_name, email FROM users ORDER BY username LIMIT $1 OFFSET $2")
+        .bind(request.amount)
+        .bind(request.start)
+        .fetch_all(&data.pool)
+        .await;
+
+    if let Err(error) = row {
+        error!("{}", error);
+        return Ok(HttpResponse::InternalServerError().finish());
+    }
+
+    let accounts: Vec<Response> = row.unwrap();
+
+    Ok(HttpResponse::Ok().json(accounts))
+}
+