[Init] Initial commit - NetMesh terminal manager

application/state/sftp/sftpTreeSelectionStore.ts

@@ -0,0 +1,153 @@
+import { useCallback, useSyncExternalStore } from "react";
+
+export interface SftpTreeSelectionItem {
+  path: string;
+  name: string;
+  isDirectory: boolean;
+  sourcePath: string;
+}
+
+interface SftpTreeSelectionState {
+  visibleItems: SftpTreeSelectionItem[];
+  visibleItemsByPath: Map<string, SftpTreeSelectionItem>;
+  visibleIndexByPath: Map<string, number>;
+  visiblePathsSet: Set<string>;
+  selectedPaths: Set<string>;
+}
+
+const EMPTY_PATHS = new Set<string>();
+
+const EMPTY_STATE: SftpTreeSelectionState = {
+  visibleItems: [],
+  visibleItemsByPath: new Map(),
+  visibleIndexByPath: new Map(),
+  visiblePathsSet: new Set(),
+  selectedPaths: EMPTY_PATHS,
+};
+
+type Listener = () => void;
+
+const paneStates = new Map<string, SftpTreeSelectionState>();
+const paneListeners = new Map<string, Set<Listener>>();
+
+const notifyPaneListeners = (paneId: string) => {
+  paneListeners.get(paneId)?.forEach((listener) => listener());
+};
+
+const getPaneState = (paneId: string): SftpTreeSelectionState =>
+  paneStates.get(paneId) ?? EMPTY_STATE;
+
+const setPaneState = (
+  paneId: string,
+  updater: (state: SftpTreeSelectionState) => SftpTreeSelectionState,
+) => {
+  const prev = getPaneState(paneId);
+  const next = updater(prev);
+  if (next === prev) return;
+  if (next.visibleItems.length === 0 && next.selectedPaths.size === 0) {
+    paneStates.delete(paneId);
+  } else {
+    paneStates.set(paneId, next);
+  }
+  notifyPaneListeners(paneId);
+};
+
+export const sftpTreeSelectionStore = {
+  getPaneState,
+
+  getSelectedItems: (paneId: string): SftpTreeSelectionItem[] => {
+    const state = getPaneState(paneId);
+    const result: SftpTreeSelectionItem[] = [];
+    for (const path of state.selectedPaths) {
+      const item = state.visibleItemsByPath.get(path);
+      if (item) result.push(item);
+    }
+    return result;
+  },
+
+  setVisibleItems: (paneId: string, visibleItems: SftpTreeSelectionItem[]) => {
+    const visibleItemsByPath = new Map<string, SftpTreeSelectionItem>();
+    const visibleIndexByPath = new Map<string, number>();
+    const visiblePathsSet = new Set(visibleItems.map((item) => item.path));
+    visibleItems.forEach((item, index) => {
+      visibleItemsByPath.set(item.path, item);
+      visibleIndexByPath.set(item.path, index);
+    });
+    setPaneState(paneId, (state) => {
+      const newSelected = new Set([...state.selectedPaths].filter((p) => visiblePathsSet.has(p)));
+      const changed =
+        newSelected.size !== state.selectedPaths.size ||
+        [...newSelected].some((p) => !state.selectedPaths.has(p));
+      return {
+        visibleItems,
+        visibleItemsByPath,
+        visibleIndexByPath,
+        visiblePathsSet,
+        selectedPaths: changed ? newSelected : state.selectedPaths,
+      };
+    });
+  },
+
+  setSelection: (paneId: string, selectedPaths: Iterable<string>) => {
+    setPaneState(paneId, (state) => ({
+      ...state,
+      selectedPaths: new Set(Array.from(selectedPaths).filter((path) => state.visiblePathsSet.has(path))),
+    }));
+  },
+
+  clearSelection: (paneId: string) => {
+    setPaneState(paneId, (state) => ({ ...state, selectedPaths: EMPTY_PATHS }));
+  },
+
+  clearAllExcept: (paneIdsToKeep?: Iterable<string>) => {
+    const keep = new Set(paneIdsToKeep ?? []);
+    Array.from(paneStates.keys()).forEach((paneId) => {
+      if (keep.has(paneId)) return;
+      setPaneState(paneId, (state) => {
+        if (state.selectedPaths.size === 0) return state;
+        return { ...state, selectedPaths: EMPTY_PATHS };
+      });
+    });
+  },
+
+  selectAllVisible: (paneId: string) => {
+    setPaneState(paneId, (state) => ({
+      ...state,
+      selectedPaths: new Set(
+        state.visibleItems.map((item) => item.path),
+      ),
+    }));
+  },
+
+  clearPane: (paneId: string) => {
+    if (!paneStates.has(paneId)) return;
+    paneStates.delete(paneId);
+    notifyPaneListeners(paneId);
+  },
+
+  subscribe: (paneId: string, listener: Listener) => {
+    const listeners = paneListeners.get(paneId) ?? new Set<Listener>();
+    listeners.add(listener);
+    paneListeners.set(paneId, listeners);
+    return () => {
+      const current = paneListeners.get(paneId);
+      if (!current) return;
+      current.delete(listener);
+      if (current.size === 0) {
+        paneListeners.delete(paneId);
+      }
+    };
+  },
+};
+
+export const useSftpTreeSelectionState = (paneId: string): SftpTreeSelectionState => {
+  const subscribe = useCallback(
+    (listener: () => void) => sftpTreeSelectionStore.subscribe(paneId, listener),
+    [paneId],
+  );
+  return useSyncExternalStore(
+    subscribe,
+    () => sftpTreeSelectionStore.getPaneState(paneId),
+    () => sftpTreeSelectionStore.getPaneState(paneId),
+  );
+};