init Preload with validate related argument options

src/main.rs

@@ -9,9 +9,10 @@ mod torrent;
 mod trackers;
 
 use anyhow::Result;
+use config::Config;
 use debug::Debug;
 use index::Index;
-use preload::Preload;
+use peers::Peers;
 use rss::Rss;
 use std::{collections::HashSet, num::NonZero, path::PathBuf, time::Duration};
 use torrent::Torrent;
@@ -28,20 +29,17 @@ async fn main() -> Result<()> {
     use tokio::time;
 
     // init components
-    let config = config::Config::parse();
+    let config = Config::parse();
     let debug = Debug::init(&config.debug)?;
-    let peers = peers::Peers::init(&config.initial_peer)?;
+    let peers = Peers::init(&config.initial_peer)?;
-    let preload = config.preload.map(|ref p| {
+    let preload = preload::init(
-        Preload::init(
+        config.preload,
-            p,
         config.preload_regex,
         config.preload_max_filecount,
         config.preload_max_filesize,
         config.preload_total_size,
         config.clear,
-        )
+    )?;
-        .unwrap()
-    });
     let trackers = Trackers::init(&config.tracker)?;
     let torrent = config.export_torrents.map(|p| Torrent::init(&p).unwrap());
     let session = librqbit::Session::new_with_opts(

src/preload.rs

@@ -11,7 +11,7 @@ pub struct Preload {
 }
 
 impl Preload {
-    pub fn init(
+    fn init(
         directory: &str,
         regex: Option<String>,
         max_filecount: Option<usize>,
@@ -89,3 +89,35 @@ impl Preload {
         self.regex.as_ref().is_some_and(|r| r.is_match(pattern))
     }
 }
+
+/// Init `Preload` with validate related argument options
+pub fn init(
+    path: Option<String>,
+    regex: Option<String>,
+    max_filecount: Option<usize>,
+    max_filesize: Option<u64>,
+    total_size: Option<u64>,
+    clear: bool,
+) -> Result<Option<Preload>> {
+    Ok(match path {
+        Some(ref p) => Some(Preload::init(
+            p,
+            regex,
+            max_filecount,
+            max_filesize,
+            total_size,
+            clear,
+        )?),
+        None => {
+            if regex.is_some()
+                || max_filecount.is_some()
+                || max_filesize.is_some()
+                || total_size.is_some()
+                || clear
+            {
+                bail!("`--preload` directory is required for this configuration!")
+            }
+            None
+        }
+    })
+}