[Init] Initial commit - NetMesh terminal manager

application/state/sftp/useSftpSessionErrors.ts

@@ -0,0 +1,99 @@
+import { useCallback } from "react";
+import type { MutableRefObject } from "react";
+import type { Host } from "../../../domain/models";
+import type { SftpPane } from "./types";
+
+interface UseSftpSessionErrorsParams {
+  getActivePane: (side: "left" | "right") => SftpPane | null;
+  leftTabsRef: MutableRefObject<{ tabs: SftpPane[]; activeTabId: string | null }>;
+  rightTabsRef: MutableRefObject<{ tabs: SftpPane[]; activeTabId: string | null }>;
+  updateActiveTab: (
+    side: "left" | "right",
+    updater: (prev: SftpPane) => SftpPane,
+  ) => void;
+  navSeqRef: MutableRefObject<{ left: number; right: number }>;
+  lastConnectedHostRef: MutableRefObject<{ left: Host | "local" | null; right: Host | "local" | null }>;
+  releaseConnection: (connectionId: string) => Promise<void>;
+}
+
+/**
+ * Whether we still know enough to reconnect after a session drop.
+ * Prefer reconnect over wiping the pane to the empty "select host" screen —
+ * that wipe was especially easy to hit when listing "/" failed/timed out on
+ * some hosts while the file list was empty or lastHost had raced away.
+ */
+export function canReconnectSftpPane(params: {
+  lastHost: Host | "local" | null;
+  connection: SftpPane["connection"];
+}): boolean {
+  const { lastHost, connection } = params;
+  if (lastHost && lastHost !== "local") return true;
+  if (lastHost === "local") return true;
+  if (connection && !connection.isLocal && !!connection.hostId) return true;
+  if (connection?.isLocal) return true;
+  return false;
+}
+
+export const useSftpSessionErrors = ({
+  getActivePane,
+  leftTabsRef,
+  rightTabsRef,
+  updateActiveTab,
+  navSeqRef,
+  lastConnectedHostRef,
+  releaseConnection,
+}: UseSftpSessionErrorsParams) =>
+  useCallback(
+    (side: "left" | "right", _error: Error) => {
+      const pane = getActivePane(side);
+      const sideTabs = side === "left" ? leftTabsRef.current : rightTabsRef.current;
+
+      if (!pane || !sideTabs.activeTabId) return;
+
+      if (pane.connection) {
+        void releaseConnection(pane.connection.id);
+      }
+
+      navSeqRef.current[side] += 1;
+
+      const lastHost = lastConnectedHostRef.current[side];
+      const canReconnect = canReconnectSftpPane({
+        lastHost,
+        connection: pane.connection,
+      });
+
+      if (canReconnect) {
+        // Keep the connection object (host identity + path) so the UI does not
+        // collapse into the empty host picker when listing root (or any path)
+        // fails with a transient session error on some servers.
+        updateActiveTab(side, (prev) => ({
+          ...prev,
+          reconnecting: true,
+          loading: false,
+          error: "sftp.error.connectionLostReconnecting",
+        }));
+        return;
+      }
+
+      // No host identity left — fall back to empty picker.
+      updateActiveTab(side, (prev) => ({
+        ...prev,
+        connection: null,
+        files: [],
+        loading: false,
+        reconnecting: false,
+        error: "sftp.error.sessionLost",
+        selectedFiles: new Set(),
+        filter: "",
+      }));
+    },
+    [
+      getActivePane,
+      leftTabsRef,
+      rightTabsRef,
+      updateActiveTab,
+      navSeqRef,
+      lastConnectedHostRef,
+      releaseConnection,
+    ],
+  );