feat: add fallback to wg show transfer parsing when dump command fails on Windows

Add read_windows_metrics_from_show function that parses human-readable transfer output from wg show command when wg show dump fails. Add parse_human_wireguard_bytes helper to convert human-readable byte values (B, KiB, MiB, GiB, TiB) to u64. Update direct_windows_metrics to fall back to transfer parsing instead of returning zero metrics when dump command fails.

desktop-client/src-tauri/src/tunnel_manager.rs

@@ -136,11 +136,7 @@ fn direct_windows_metrics(profile_path: &Path) -> Result<TunnelMetrics, String>
         .map_err(|err| format!("Unable to query WireGuard counters: {err}"))?;
 
     if !wg_output.status.success() {
-        return Ok(TunnelMetrics {
+        return read_windows_metrics_from_show(tunnel_name);
-            active: true,
-            rx_bytes: 0,
-            tx_bytes: 0,
-        });
     }
 
     let stdout = String::from_utf8_lossy(&wg_output.stdout);
@@ -163,6 +159,77 @@ fn direct_windows_metrics(profile_path: &Path) -> Result<TunnelMetrics, String>
     })
 }
 
+#[cfg(target_os = "windows")]
+fn read_windows_metrics_from_show(tunnel_name: &str) -> Result<TunnelMetrics, String> {
+    let wg = find_windows_wg()?;
+    let mut command = Command::new(wg);
+    command
+        .arg("show")
+        .arg(tunnel_name)
+        .creation_flags(CREATE_NO_WINDOW);
+    let output = command
+        .output()
+        .map_err(|err| format!("Unable to query WireGuard transfer text: {err}"))?;
+
+    if !output.status.success() {
+        return Ok(TunnelMetrics {
+            active: true,
+            rx_bytes: 0,
+            tx_bytes: 0,
+        });
+    }
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let mut rx_bytes = 0_u64;
+    let mut tx_bytes = 0_u64;
+
+    for line in stdout.lines() {
+        let trimmed = line.trim();
+        if let Some(rest) = trimmed.strip_prefix("transfer:") {
+            let parts: Vec<&str> = rest.split(',').collect();
+            if let Some(received) = parts.first() {
+                rx_bytes = parse_human_wireguard_bytes(received);
+            }
+            if let Some(sent) = parts.get(1) {
+                tx_bytes = parse_human_wireguard_bytes(sent);
+            }
+        }
+    }
+
+    Ok(TunnelMetrics {
+        active: true,
+        rx_bytes,
+        tx_bytes,
+    })
+}
+
+#[cfg(target_os = "windows")]
+fn parse_human_wireguard_bytes(value: &str) -> u64 {
+    let cleaned = value
+        .replace("received", "")
+        .replace("sent", "")
+        .trim()
+        .to_string();
+    let mut parts = cleaned.split_whitespace();
+    let amount = parts
+        .next()
+        .map(|raw| raw.replace(',', "."))
+        .and_then(|raw| raw.parse::<f64>().ok())
+        .unwrap_or(0.0);
+    let unit = parts.next().unwrap_or("B");
+
+    let multiplier = match unit {
+        "B" => 1.0,
+        "KiB" => 1024.0,
+        "MiB" => 1024.0 * 1024.0,
+        "GiB" => 1024.0 * 1024.0 * 1024.0,
+        "TiB" => 1024.0 * 1024.0 * 1024.0 * 1024.0,
+        _ => 1.0,
+    };
+
+    (amount * multiplier) as u64
+}
+
 #[cfg(target_os = "windows")]
 fn find_windows_wg() -> Result<PathBuf, String> {
     let candidates = [