[Init] Initial commit - NetMesh terminal manager

domain/focusSidebarHostDrop.ts

@@ -0,0 +1,55 @@
+export const FOCUS_SIDEBAR_HOST_DRAG_TYPE = 'host-id';
+export const FOCUS_SIDEBAR_SESSION_DRAG_TYPE = 'workspace-focus-session-id';
+
+export type FocusSidebarDragKind = 'session-reorder' | 'host-append' | null;
+
+export function dataTransferHasType(
+  types: ArrayLike<string> | readonly string[],
+  type: string,
+): boolean {
+  return Array.from(types as ArrayLike<string>).includes(type);
+}
+
+/**
+ * Decide how the focus-mode workspace sidebar should treat an in-progress drag.
+ * Session reorder wins when this sidebar started the drag, so a host mime that
+ * happens to be present cannot steal reorder gestures.
+ */
+export function resolveFocusSidebarDragKind(input: {
+  types: ArrayLike<string> | readonly string[];
+  activeSessionDragId?: string | null;
+}): FocusSidebarDragKind {
+  if (
+    input.activeSessionDragId
+    || dataTransferHasType(input.types, FOCUS_SIDEBAR_SESSION_DRAG_TYPE)
+  ) {
+    return 'session-reorder';
+  }
+  if (dataTransferHasType(input.types, FOCUS_SIDEBAR_HOST_DRAG_TYPE)) {
+    return 'host-append';
+  }
+  return null;
+}
+
+export function readHostIdFromDataTransfer(
+  getData: (type: string) => string,
+): string | null {
+  const hostId = getData(FOCUS_SIDEBAR_HOST_DRAG_TYPE)?.trim();
+  return hostId || null;
+}
+
+export function appendHostFromWorkspaceDrop(input: {
+  types: ArrayLike<string> | readonly string[];
+  getData: (type: string) => string;
+  workspaceId: string;
+  activeSessionDragId?: string | null;
+  onAppendHostToWorkspace: (workspaceId: string, hostId: string) => void;
+}): boolean {
+  if (resolveFocusSidebarDragKind(input) !== 'host-append') return false;
+
+  const hostId = readHostIdFromDataTransfer(input.getData);
+  if (!hostId) return false;
+
+  input.onAppendHostToWorkspace(input.workspaceId, hostId);
+  return true;
+}