chore: handle download interuptions

src-tauri/src/downloader.rs

@@ -308,12 +308,40 @@ impl Downloader {
       .resolve_download_url(browser_type.clone(), version, download_info)
       .await?;
 
-    // Determine if we have a partial file to resume
+    // Check existing file size — if it matches the expected size, skip download
     let mut existing_size: u64 = 0;
     if let Ok(meta) = std::fs::metadata(&file_path) {
       existing_size = meta.len();
     }
 
+    // Do a HEAD request to get the expected file size for skip/resume decisions
+    let head_response = self
+      .client
+      .head(&download_url)
+      .header(
+        "User-Agent",
+        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36",
+      )
+      .send()
+      .await
+      .ok();
+
+    let expected_size = head_response.as_ref().and_then(|r| r.content_length());
+
+    // If existing file matches expected size, skip download entirely
+    if existing_size > 0 {
+      if let Some(expected) = expected_size {
+        if existing_size == expected {
+          log::info!(
+            "Archive {} already exists with correct size ({} bytes), skipping download",
+            file_path.display(),
+            existing_size
+          );
+          return Ok(file_path);
+        }
+      }
+    }
+
     // Build request, add Range only if we have bytes. If the server responds with 416 (Range Not
     // Satisfiable), delete the partial file and retry once without the Range header.
     let response = {
@@ -683,11 +711,16 @@ impl Downloader {
           // Do not remove the archive here. We keep it until verification succeeds.
         }
         Err(e) => {
-          // Do not remove the archive or extracted files. Just drop the registry entry
-          // so it won't be reported as downloaded.
+          log::error!("Extraction failed for {browser_str} {version}: {e}");
+
+          // Delete the corrupt/invalid archive so a fresh download happens next time
+          if download_path.exists() {
+            log::info!("Deleting corrupt archive: {}", download_path.display());
+            let _ = std::fs::remove_file(&download_path);
+          }
+
           let _ = self.registry.remove_browser(&browser_str, &version);
           let _ = self.registry.save();
-          // Remove browser-version pair from downloading set on error
           {
             let mut downloading = DOWNLOADING_BROWSERS.lock().unwrap();
             downloading.remove(&download_key);
@@ -696,6 +729,20 @@ impl Downloader {
             let mut tokens = DOWNLOAD_CANCELLATION_TOKENS.lock().unwrap();
             tokens.remove(&download_key);
           }
+
+          // Emit error stage so the UI shows a toast
+          let progress = DownloadProgress {
+            browser: browser_str.clone(),
+            version: version.clone(),
+            downloaded_bytes: 0,
+            total_bytes: None,
+            percentage: 0.0,
+            speed_bytes_per_sec: 0.0,
+            eta_seconds: None,
+            stage: "error".to_string(),
+          };
+          let _ = events::emit("download-progress", &progress);
+
           return Err(format!("Failed to extract browser: {e}").into());
         }
       }

src-tauri/src/extraction.rs

@@ -7,7 +7,7 @@ use crate::downloader::DownloadProgress;
 use crate::events;
 
 #[cfg(target_os = "macos")]
-use std::process::Command;
+use tokio::process::Command;
 
 #[cfg(target_os = "macos")]
 use std::fs::create_dir_all;
@@ -232,17 +232,8 @@ impl Extractor {
     &self,
     file_path: &Path,
   ) -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
-    // First check file extension for DMG files since they're common on macOS
-    // and can have misleading magic numbers
-    if let Some(ext) = file_path.extension().and_then(|ext| ext.to_str()) {
-      if ext.to_lowercase() == "dmg" {
-        return Ok("dmg".to_string());
-      }
-      if ext.to_lowercase() == "msi" {
-        return Ok("msi".to_string());
-      }
-    }
-
+    // Always check magic bytes first — the file extension may be wrong
+    // (e.g. CDN serving a ZIP with .dmg extension)
     let mut file = File::open(file_path)?;
     let mut buffer = [0u8; 12]; // Read first 12 bytes for magic number detection
     file.read_exact(&mut buffer)?;
@@ -357,16 +348,20 @@ impl Extractor {
       .args([
         "attach",
         "-nobrowse",
+        "-noverify",
+        "-noautoopen",
         "-mountpoint",
         mount_point.to_str().unwrap(),
         dmg_path.to_str().unwrap(),
       ])
-      .output()?;
+      .stdin(std::process::Stdio::null())
+      .output()
+      .await?;
 
     if !output.status.success() {
       let stderr = String::from_utf8_lossy(&output.stderr);
       let stdout = String::from_utf8_lossy(&output.stdout);
-      log::info!("Failed to mount DMG. stdout: {stdout}, stderr: {stderr}");
+      log::error!("Failed to mount DMG. stdout: {stdout}, stderr: {stderr}");
 
       // Clean up mount point before returning error
       let _ = fs::remove_dir_all(&mount_point);
@@ -382,12 +377,13 @@ impl Extractor {
     let app_entry = match app_result {
       Ok(app_path) => app_path,
       Err(e) => {
-        log::info!("Failed to find .app in mount point: {e}");
+        log::error!("Failed to find .app in mount point: {e}");
 
         // Try to unmount before returning error
         let _ = Command::new("hdiutil")
           .args(["detach", "-force", mount_point.to_str().unwrap()])
-          .output();
+          .output()
+          .await;
         let _ = fs::remove_dir_all(&mount_point);
 
         return Err("No .app found after extraction".into());
@@ -407,16 +403,18 @@ impl Extractor {
         app_entry.to_str().unwrap(),
         app_path.to_str().unwrap(),
       ])
-      .output()?;
+      .output()
+      .await?;
 
     if !output.status.success() {
       let stderr = String::from_utf8_lossy(&output.stderr);
-      log::info!("Failed to copy app: {stderr}");
+      log::error!("Failed to copy app: {stderr}");
 
       // Unmount before returning error
       let _ = Command::new("hdiutil")
         .args(["detach", "-force", mount_point.to_str().unwrap()])
-        .output();
+        .output()
+        .await;
       let _ = fs::remove_dir_all(&mount_point);
 
       return Err(format!("Failed to copy app: {stderr}").into());
@@ -427,18 +425,21 @@ impl Extractor {
     // Remove quarantine attributes
     let _ = Command::new("xattr")
       .args(["-dr", "com.apple.quarantine", app_path.to_str().unwrap()])
-      .output();
+      .output()
+      .await;
 
     let _ = Command::new("xattr")
       .args(["-cr", app_path.to_str().unwrap()])
-      .output();
+      .output()
+      .await;
 
     log::info!("Removed quarantine attributes");
 
     // Unmount the DMG
     let output = Command::new("hdiutil")
       .args(["detach", mount_point.to_str().unwrap()])
-      .output()?;
+      .output()
+      .await?;
 
     if !output.status.success() {
       let stderr = String::from_utf8_lossy(&output.stderr);

src-tauri/src/geoip_downloader.rs

@@ -174,6 +174,13 @@ impl GeoIPDownloader {
 
     let mmdb_path = Self::get_mmdb_file_path()?;
 
+    // Always download to a temp file first, then atomically rename.
+    // This prevents corruption if the app is closed mid-download.
+    let temp_path = mmdb_path.with_extension("mmdb.downloading");
+
+    // Remove any leftover temp file from a previous interrupted download
+    let _ = fs::remove_file(&temp_path).await;
+
     // Download the file
     let response = self.client.get(&download_url).send().await?;
 
@@ -189,7 +196,7 @@ impl GeoIPDownloader {
 
     let total_size = response.content_length().unwrap_or(0);
     let mut downloaded: u64 = 0;
-    let mut file = fs::File::create(&mmdb_path).await?;
+    let mut file = fs::File::create(&temp_path).await?;
     let mut stream = response.bytes_stream();
 
     use futures_util::StreamExt;
@@ -237,6 +244,10 @@ impl GeoIPDownloader {
     }
 
     file.flush().await?;
+    drop(file);
+
+    // Atomically replace the old database with the new one
+    fs::rename(&temp_path, &mmdb_path).await?;
 
     // Write download timestamp
     let timestamp_path = Self::get_timestamp_path();

src-tauri/src/lib.rs

@@ -293,9 +293,17 @@ async fn fetch_dynamic_proxy(
   url: String,
   format: String,
 ) -> Result<crate::browser::ProxySettings, String> {
-  crate::proxy_manager::PROXY_MANAGER
+  let settings = crate::proxy_manager::PROXY_MANAGER
     .fetch_dynamic_proxy(&url, &format)
+    .await?;
+
+  // Validate the proxy actually works by routing through a temporary local proxy
+  crate::proxy_manager::PROXY_MANAGER
+    .check_proxy_validity("_dynamic_test", &settings)
     .await
+    .map_err(|e| format!("Proxy resolved but connection failed: {e}"))?;
+
+  Ok(settings)
 }
 
 #[tauri::command]

src/hooks/use-browser-download.ts

@@ -335,6 +335,23 @@ export function useBrowserDownload() {
                 `download-${browserName.toLowerCase()}-${progress.version}`,
               );
               setDownloadProgress(null);
+            } else if (progress.stage === "error") {
+              setDownloadingBrowsers((prev) => {
+                const next = new Set(prev);
+                next.delete(progress.browser);
+                return next;
+              });
+              dismissToast(
+                `download-${browserName.toLowerCase()}-${progress.version}`,
+              );
+              setDownloadProgress(null);
+              showErrorToast(
+                `${browserName} ${progress.version}: extraction failed`,
+                {
+                  description:
+                    "The corrupt file was deleted. It will be re-downloaded on next attempt.",
+                },
+              );
             } else if (progress.stage === "completed") {
               setDownloadingBrowsers((prev) => {
                 const next = new Set(prev);