[Init] Initial commit - NetMesh terminal manager

application/state/sftp/browseSessionLifecycle.ts

@@ -0,0 +1,113 @@
+/**
+ * Browse vs transfer session lifecycle helpers.
+ *
+ * FileZilla model: a *closed* terminal SFTP side panel can soft-close its browse
+ * SFTP channels while bulk transfers keep dedicated pool connections (and any
+ * leased browse sessions held by in-flight streams). Switching to another side
+ * panel tool (History / System / …) must keep browse warm — the owner stays
+ * mounted for instant switch-back, and parking would force reconnect + reload.
+ */
+
+export function isBrowseSessionInteractive(params: {
+  surfaceVisible: boolean;
+  /**
+   * Terminal side panel still open for this owner (another tool may be focused).
+   * Keeps browse sessions alive across tool switches without treating that as a
+   * full panel dismiss.
+   */
+  ownerPanelOpen?: boolean;
+  hasOwnedEditorTab: boolean;
+  /** External editor temp files (Notepad++ etc.) still need the browse session. */
+  hasActiveExternalEdit?: boolean;
+}): boolean {
+  return params.surfaceVisible
+    || !!params.ownerPanelOpen
+    || params.hasOwnedEditorTab
+    || !!params.hasActiveExternalEdit;
+}
+
+export function listRemoteBrowseConnectionIds(
+  tabs: ReadonlyArray<{
+    connection: { id: string; isLocal: boolean } | null;
+  }>,
+): string[] {
+  const ids = new Set<string>();
+  for (const tab of tabs) {
+    const connection = tab.connection;
+    if (!connection || connection.isLocal) continue;
+    ids.add(connection.id);
+  }
+  return [...ids];
+}
+
+/** Stable SFTP pane tab ids for editor ownership across browse reconnects. */
+export function listRemoteBrowseSftpTabIds(
+  tabs: ReadonlyArray<{
+    id: string;
+    connection: { id: string; isLocal: boolean } | null;
+  }>,
+): string[] {
+  const ids = new Set<string>();
+  for (const tab of tabs) {
+    const connection = tab.connection;
+    if (!connection || connection.isLocal) continue;
+    ids.add(tab.id);
+  }
+  return [...ids];
+}
+
+export function shouldParkBrowseSessions(params: {
+  interactive: boolean;
+  /** True after we already soft-closed browse while the owner stayed mounted. */
+  browseParked: boolean;
+  /** Defer park while unfinished transfers may still use browse sessions pre-lease. */
+  activeTransfersCount?: number;
+  /**
+   * Defer park while an external editor still holds a downloaded temp file.
+   * Parking calls closeSftp, which deletes those temps and breaks save/sync.
+   */
+  activeExternalEditCount?: number;
+}): boolean {
+  if (params.activeTransfersCount && params.activeTransfersCount > 0) return false;
+  if (params.activeExternalEditCount && params.activeExternalEditCount > 0) return false;
+  return !params.interactive && !params.browseParked;
+}
+
+export function shouldRestoreBrowseSessions(params: {
+  interactive: boolean;
+  browseParked: boolean;
+}): boolean {
+  return params.interactive && params.browseParked;
+}
+
+export interface BrowseSessionEntry {
+  connectionId: string;
+  sftpId: string;
+}
+
+/** Snapshot + clear the connectionId→sftpId map used by the file browser. */
+export function takeBrowseSessionsForClose(
+  sessions: Map<string, string>,
+): BrowseSessionEntry[] {
+  const entries = [...sessions.entries()].map(([connectionId, sftpId]) => ({
+    connectionId,
+    sftpId,
+  }));
+  sessions.clear();
+  return entries;
+}
+
+export function listRemoteConnectionIdsForRestore(params: {
+  leftTabs: ReadonlyArray<{ connection: { id: string; isLocal: boolean } | null }>;
+  rightTabs: ReadonlyArray<{ connection: { id: string; isLocal: boolean } | null }>;
+  liveSessionConnectionIds: ReadonlySet<string>;
+}): string[] {
+  const ids = new Set<string>();
+  for (const tab of [...params.leftTabs, ...params.rightTabs]) {
+    const connection = tab.connection;
+    if (!connection || connection.isLocal) continue;
+    if (params.liveSessionConnectionIds.has(connection.id)) continue;
+    ids.add(connection.id);
+  }
+  return [...ids];
+}