Add file watcher to re-generate thumbnails

Previously files added while the server is running would not have
thumbnails until after the server was restarted. Now we watch the
BASE_PATH for added/renamed files in order to re-gen the thumbnail.

src/main.rs

@@ -10,11 +10,13 @@ use chrono::{Duration, Utc};
 use data::{AddFavoriteRequest, LoginRequest, ThumbnailRequest};
 use futures::stream::StreamExt;
 use jsonwebtoken::{encode, EncodingKey, Header};
+use notify::{watcher, DebouncedEvent, RecursiveMode, Watcher};
 use rayon::prelude::*;
 use serde::Serialize;
 use std::fs::File;
 use std::io::prelude::*;
 use std::path::{Path, PathBuf};
+use std::sync::mpsc::channel;
 
 use crate::data::{secret_key, Claims, CreateAccountRequest, Token};
 use crate::database::{add_favorite, create_user, get_favorites, get_user, user_exists};
@@ -305,6 +307,31 @@ async fn create_thumbnails() {
 async fn main() -> std::io::Result<()> {
     create_thumbnails().await;
 
+    tokio::spawn(async {
+        let (wtx, wrx) = channel();
+        let mut watcher = watcher(wtx, std::time::Duration::from_secs(10)).unwrap();
+        watcher
+            .watch(dotenv::var("BASE_PATH").unwrap(), RecursiveMode::Recursive)
+            .unwrap();
+
+        loop {
+            let ev = wrx.recv_timeout(std::time::Duration::from_secs(5));
+            match ev {
+                Ok(event) => {
+                    match event {
+                        DebouncedEvent::Create(_) => create_thumbnails().await,
+                        DebouncedEvent::Rename(_, _) => create_thumbnails().await,
+                        _ => continue,
+                    };
+                }
+                Err(e) => {
+                    println!("Event: {:?}", e);
+                    // break;
+                }
+            }
+        }
+    });
+
     HttpServer::new(|| {
         App::new()
             .service(register)