[Init] Initial commit - NetMesh terminal manager

application/state/sftp/uploadTargetPin.ts

@@ -0,0 +1,92 @@
+import type { SftpPane } from "./types";
+
+export type UploadEndpointPin = {
+  isLocal: boolean;
+  hostId: string | null;
+  cacheKey: string | null;
+  /** When present, reconnecting the same tab is still a target change. */
+  connectionId?: string;
+};
+
+export function captureUploadEndpoint(
+  connection: NonNullable<SftpPane["connection"]>,
+  connectionCacheKeyMap: Map<string, string>,
+  options?: { pinConnectionId?: boolean },
+): UploadEndpointPin {
+  return {
+    isLocal: connection.isLocal,
+    hostId: connection.isLocal ? null : (connection.hostId ?? null),
+    cacheKey: connection.isLocal
+      ? "local"
+      : (connectionCacheKeyMap.get(connection.id) ?? null),
+    ...(options?.pinConnectionId ? { connectionId: connection.id } : undefined),
+  };
+}
+
+export function assertUploadEndpointUnchanged(
+  connection: NonNullable<SftpPane["connection"]>,
+  expected: UploadEndpointPin,
+  connectionCacheKeyMap: Map<string, string>,
+): void {
+  if (expected.connectionId && connection.id !== expected.connectionId) {
+    throw new Error("Upload target changed before the transfer started");
+  }
+  if (connection.isLocal !== expected.isLocal) {
+    throw new Error("Upload target changed before the transfer started");
+  }
+  if (connection.isLocal) return;
+  if ((connection.hostId ?? null) !== expected.hostId) {
+    throw new Error("Upload target changed before the transfer started");
+  }
+  if (expected.cacheKey) {
+    const liveKey = connectionCacheKeyMap.get(connection.id) ?? null;
+    // Same-host reconnect re-stamps the key; a different endpoint must stop.
+    if (liveKey && liveKey !== expected.cacheKey) {
+      throw new Error("Upload target changed before the transfer started");
+    }
+  }
+}
+
+/**
+ * Resolve the pane that should receive an external upload.
+ * Prefer stable tabId (survives reconnect) over connectionId, then active pane.
+ */
+export function resolveUploadTargetPane(params: {
+  side: "left" | "right";
+  tabId?: string;
+  connectionId?: string;
+  getActivePane: (side: "left" | "right") => SftpPane | null;
+  getPaneByTabId: (tabId: string) => SftpPane | null;
+  getPaneByConnectionId: (connectionId: string) => SftpPane | null;
+}): SftpPane {
+  const {
+    side,
+    tabId,
+    connectionId,
+    getActivePane,
+    getPaneByTabId,
+    getPaneByConnectionId,
+  } = params;
+
+  if (tabId) {
+    const pane = getPaneByTabId(tabId);
+    if (!pane?.connection) {
+      throw new Error("Upload target connection is no longer available");
+    }
+    return pane;
+  }
+
+  if (connectionId) {
+    const pane = getPaneByConnectionId(connectionId);
+    if (!pane?.connection) {
+      throw new Error("Upload target connection is no longer available");
+    }
+    return pane;
+  }
+
+  const pane = getActivePane(side);
+  if (!pane?.connection) {
+    throw new Error("No active connection");
+  }
+  return pane;
+}