[V1] Flatpak Release + Buffering Fix & Storage Management

src-tauri/src/lib.rs

@@ -1,14 +1,77 @@
+use std::path::PathBuf;
 use std::sync::Mutex;
+use nix::sys::statvfs::statvfs;
+use serde::Serialize;
 use tauri::Manager;
 use tauri_plugin_shell::{ShellExt, process::CommandChild};
+use walkdir::WalkDir;
 
 struct ServerState(Mutex<Option<CommandChild>>);
 
+#[derive(Serialize)]
+pub struct StorageInfo {
+    manga_bytes: u64,
+    total_bytes: u64,
+    free_bytes:  u64,
+    path:        String,
+}
+
+fn resolve_downloads_path(downloads_path: &str) -> PathBuf {
+    if !downloads_path.trim().is_empty() {
+        return PathBuf::from(downloads_path);
+    }
+    let base = std::env::var("XDG_DATA_HOME")
+        .map(PathBuf::from)
+        .unwrap_or_else(|_| {
+            dirs::home_dir()
+                .unwrap_or_else(|| PathBuf::from("/"))
+                .join(".local/share")
+        });
+    base.join("Tachidesk/downloads")
+}
+
+#[tauri::command]
+fn get_storage_info(downloads_path: String) -> Result<StorageInfo, String> {
+    let path = resolve_downloads_path(&downloads_path);
+
+    let manga_bytes = if path.exists() {
+        WalkDir::new(&path)
+            .into_iter()
+            .filter_map(|e| e.ok())
+            .filter_map(|e| e.metadata().ok())
+            .filter(|m| m.is_file())
+            .map(|m| m.len())
+            .sum()
+    } else {
+        0
+    };
+
+    let stat_path = if path.exists() { path.clone() } else {
+        dirs::home_dir().unwrap_or_else(|| PathBuf::from("/"))
+    };
+    let vfs = statvfs(&stat_path).map_err(|e| e.to_string())?;
+
+    // f_frsize is the fundamental block size used for block counts.
+    // f_bsize (block_size()) is just the preferred I/O size and must not be
+    // used with blocks()/blocks_free() — that gives wildly wrong numbers.
+    let frsize      = vfs.fragment_size() as u64;
+    let total_bytes = vfs.blocks()            * frsize;
+    let free_bytes  = vfs.blocks_available()  * frsize;
+
+    Ok(StorageInfo {
+        manga_bytes,
+        total_bytes,
+        free_bytes,
+        path: path.to_string_lossy().into_owned(),
+    })
+}
+
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
     tauri::Builder::default()
         .plugin(tauri_plugin_shell::init())
         .manage(ServerState(Mutex::new(None)))
+        .invoke_handler(tauri::generate_handler![get_storage_info])
         .setup(|app| {
             let shell = app.shell();
             let app_handle = app.handle().clone();