refactoring, linting, formatting

src/workspace/useWorkspaceState.ts

@@ -0,0 +1,246 @@
+import { useCallback, useRef, useState } from "react";
+import type { PageRef } from "../pdf/pdfTypes";
+import type {
+  WorkspaceCommand,
+  WorkspaceCommandRecord,
+  WorkspaceCommandState,
+} from "./workspaceCommands";
+import {
+  createSnapshotCommand,
+  reviveWorkspaceCommand,
+  toWorkspaceCommandRecord,
+} from "./workspaceCommands";
+
+function createId(prefix: string): string {
+  if (typeof crypto !== "undefined" && crypto.randomUUID) {
+    return crypto.randomUUID();
+  }
+
+  return `${prefix}_${Date.now()}_${Math.random().toString(36).slice(2)}`;
+}
+
+export function createWorkspaceId(): string {
+  return createId("workspace");
+}
+
+export function defaultWorkspaceNameFromPdfName(pdfName: string): string {
+  return pdfName.replace(/\.pdf$/i, "") || "Untitled workspace";
+}
+
+export function createPageRefId(): string {
+  return createId("page");
+}
+
+export function createInitialPageRefs(pageCount: number): PageRef[] {
+  return Array.from({ length: pageCount }, (_, sourcePageIndex) => ({
+    id: createPageRefId(),
+    sourcePageIndex,
+    rotation: 0,
+  }));
+}
+
+export function normalizeRotation(rotation: number | undefined): number {
+  return (((rotation ?? 0) % 360) + 360) % 360;
+}
+
+type SetStateAction<T> = T | ((previous: T) => T);
+
+interface UseWorkspaceStateOptions {
+  onContentChanged?: () => void;
+}
+
+interface ReplaceWorkspaceStateOptions {
+  pages?: PageRef[];
+  selectedPageIds?: string[];
+  lastSelectedVisualIndex?: number | null;
+  history?: WorkspaceCommandRecord[];
+  redoHistory?: WorkspaceCommandRecord[];
+  dirty?: boolean;
+  message?: string | null;
+}
+
+export function useWorkspaceState({
+  onContentChanged,
+}: UseWorkspaceStateOptions = {}) {
+  const [pages, setPagesState] = useState<PageRef[]>([]);
+  const [selectedPageIds, setSelectedPageIdsState] = useState<string[]>([]);
+  const [lastSelectedVisualIndex, setLastSelectedVisualIndexState] = useState<
+    number | null
+  >(null);
+  const [workspaceDirty, setWorkspaceDirty] = useState(false);
+  const [workspaceMessage, setWorkspaceMessage] = useState<string | null>(null);
+  const [workspaceHistory, setWorkspaceHistory] = useState<
+    WorkspaceCommandRecord[]
+  >([]);
+  const [redoHistory, setRedoHistory] = useState<WorkspaceCommandRecord[]>([]);
+
+  const latestPagesRef = useRef<PageRef[]>([]);
+  const selectedPageIdsRef = useRef<string[]>([]);
+  const lastSelectedVisualIndexRef = useRef<number | null>(null);
+
+  const setPages = useCallback((action: SetStateAction<PageRef[]>) => {
+    setPagesState((previous) => {
+      const next = typeof action === "function" ? action(previous) : action;
+      latestPagesRef.current = next;
+      return next;
+    });
+  }, []);
+
+  const setSelectedPageIds = useCallback((action: SetStateAction<string[]>) => {
+    setSelectedPageIdsState((previous) => {
+      const next = typeof action === "function" ? action(previous) : action;
+      selectedPageIdsRef.current = next;
+      return next;
+    });
+  }, []);
+
+  const setLastSelectedVisualIndex = useCallback(
+    (action: SetStateAction<number | null>) => {
+      setLastSelectedVisualIndexState((previous) => {
+        const next = typeof action === "function" ? action(previous) : action;
+        lastSelectedVisualIndexRef.current = next;
+        return next;
+      });
+    },
+    [],
+  );
+
+  const getCurrentCommandState = useCallback(
+    (): WorkspaceCommandState => ({
+      pages: latestPagesRef.current,
+      selectedPageIds: selectedPageIdsRef.current,
+      lastSelectedVisualIndex: lastSelectedVisualIndexRef.current,
+    }),
+    [],
+  );
+
+  const applyCommandState = useCallback(
+    (state: WorkspaceCommandState) => {
+      setPages(state.pages);
+      setSelectedPageIds(state.selectedPageIds);
+      setLastSelectedVisualIndex(state.lastSelectedVisualIndex);
+    },
+    [setLastSelectedVisualIndex, setPages, setSelectedPageIds],
+  );
+
+  const markWorkspaceChanged = useCallback(() => {
+    setWorkspaceDirty(true);
+    setWorkspaceMessage(null);
+    onContentChanged?.();
+  }, [onContentChanged]);
+
+  const createWorkspaceCommand = useCallback(
+    (params: {
+      type: string;
+      label: string;
+      before: WorkspaceCommandState;
+      after: WorkspaceCommandState;
+      details?: Record<string, unknown>;
+    }): WorkspaceCommand =>
+      createSnapshotCommand({
+        id: createId("command"),
+        type: params.type,
+        label: params.label,
+        before: params.before,
+        after: params.after,
+        details: params.details,
+      }),
+    [],
+  );
+
+  const executeWorkspaceCommand = useCallback(
+    (command: WorkspaceCommand) => {
+      const nextState = command.do(getCurrentCommandState());
+
+      applyCommandState(nextState);
+      setWorkspaceHistory((previous) => [
+        ...previous,
+        toWorkspaceCommandRecord(command),
+      ]);
+      setRedoHistory([]);
+      markWorkspaceChanged();
+    },
+    [applyCommandState, getCurrentCommandState, markWorkspaceChanged],
+  );
+
+  const handleUndo = useCallback(() => {
+    const record = workspaceHistory[workspaceHistory.length - 1];
+    if (!record) return;
+
+    const command = reviveWorkspaceCommand(record);
+    const previousState = command.undo(getCurrentCommandState());
+
+    applyCommandState(previousState);
+    setWorkspaceHistory((previous) => previous.slice(0, -1));
+    setRedoHistory((previous) => [...previous, record]);
+    markWorkspaceChanged();
+  }, [
+    applyCommandState,
+    getCurrentCommandState,
+    markWorkspaceChanged,
+    workspaceHistory,
+  ]);
+
+  const handleRedo = useCallback(() => {
+    const record = redoHistory[redoHistory.length - 1];
+    if (!record) return;
+
+    const command = reviveWorkspaceCommand(record);
+    const nextState = command.do(getCurrentCommandState());
+
+    applyCommandState(nextState);
+    setRedoHistory((previous) => previous.slice(0, -1));
+    setWorkspaceHistory((previous) => [...previous, record]);
+    markWorkspaceChanged();
+  }, [
+    applyCommandState,
+    getCurrentCommandState,
+    markWorkspaceChanged,
+    redoHistory,
+  ]);
+
+  const replaceWorkspaceState = useCallback(
+    (state: ReplaceWorkspaceStateOptions = {}) => {
+      setPages(state.pages ?? []);
+      setSelectedPageIds(state.selectedPageIds ?? []);
+      setLastSelectedVisualIndex(state.lastSelectedVisualIndex ?? null);
+      setWorkspaceHistory(state.history ?? []);
+      setRedoHistory(state.redoHistory ?? []);
+      setWorkspaceDirty(state.dirty ?? false);
+      setWorkspaceMessage(state.message ?? null);
+    },
+    [setLastSelectedVisualIndex, setPages, setSelectedPageIds],
+  );
+
+  const resetWorkspaceState = useCallback(() => {
+    replaceWorkspaceState();
+  }, [replaceWorkspaceState]);
+
+  return {
+    pages,
+    setPages,
+    selectedPageIds,
+    setSelectedPageIds,
+    lastSelectedVisualIndex,
+    setLastSelectedVisualIndex,
+    latestPagesRef,
+
+    workspaceDirty,
+    setWorkspaceDirty,
+    workspaceMessage,
+    setWorkspaceMessage,
+    workspaceHistory,
+    setWorkspaceHistory,
+    redoHistory,
+    setRedoHistory,
+
+    getCurrentCommandState,
+    applyCommandState,
+    createWorkspaceCommand,
+    executeWorkspaceCommand,
+    handleUndo,
+    handleRedo,
+    replaceWorkspaceState,
+    resetWorkspaceState,
+  };
+}