Moved document validation into a sepparate func

src/state/get_user.rs

@@ -2,15 +2,36 @@ use crate::prelude::*;
 use futures::future::try_join;
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
-use std::fmt::Write;
-use teloxide::{net::Download, types::Document};
+use std::{fmt::Write, path::Path};
+use teloxide::{
+    net::Download,
+    types::{Document, FileMeta},
+};
 use tokio::task::spawn_blocking;
 use trim_in_place::TrimInPlace;
 
 #[inline]
-async fn download_file(bot: &Throttle<Bot>, document: &Document) -> crate::Result<Vec<u8>> {
-    let path = bot.get_file(document.file.id.as_str()).await?.path;
-    let mut data = Vec::with_capacity(document.file.size as usize);
+fn validate_document(document: Option<&Document>) -> Result<&Document, &'static str> {
+    let document = match document {
+        Some(document) => document,
+        None => return Err("You didn't send a file. Try again"),
+    };
+
+    let name = match document.file_name.as_deref() {
+        Some(name) => Path::new(name.trim_end()),
+        None => return Err("Couldn't get the name of the file. Try sending it again"),
+    };
+
+    match name.extension() {
+        Some(ext) if ext.eq_ignore_ascii_case("json") => Ok(document),
+        _ => Err("Invalid file name. You need to send a json file. Try again"),
+    }
+}
+
+#[inline]
+async fn download_file(bot: &Throttle<Bot>, file: &FileMeta) -> crate::Result<Vec<u8>> {
+    let path = bot.get_file(file.id.as_str()).await?.path;
+    let mut data = Vec::with_capacity(file.size as usize);
     bot.download_file_stream(&path)
         .try_for_each(|bytes| {
             data.extend(bytes);
@@ -131,31 +152,15 @@ pub async fn get_user(
         return Ok(());
     }
 
-    let document = match msg.document() {
-        Some(document) => document,
-        None => {
-            let msg = bot
-                .send_message(msg.chat.id, "You didn't send a file. Try again")
-                .await?;
+    let file = match validate_document(msg.document()) {
+        Ok(document) => &document.file,
+        Err(text) => {
+            let msg = bot.send_message(msg.chat.id, text).await?;
             handler.previous = MessageIds::from(&msg);
             return Ok(());
         }
     };
 
-    match document.file_name.as_deref() {
-        Some(name) if name.trim_end().ends_with(".json") => (),
-        _ => {
-            let msg = bot
-                .send_message(
-                    msg.chat.id,
-                    "Invalid file name. You need to send a json file. Try again",
-                )
-                .await?;
-            handler.previous = MessageIds::from(&msg);
-            return Ok(());
-        }
-    }
-
     let existing_names = async {
         Account::get_names(user_id, &db)
             .await?
@@ -164,7 +169,7 @@ pub async fn get_user(
             .map_err(Into::into)
     };
 
-    let (data, existing_names) = try_join(download_file(&bot, document), existing_names).await?;
+    let (data, existing_names) = try_join(download_file(&bot, file), existing_names).await?;
 
     let user = match spawn_blocking(move || user_from_vec(data, existing_names)).await? {
         Ok(Ok(user)) => user,