paint-ui/store/history-store.ts

import { create } from 'zustand';
import type { Command, HistoryState } from '@/types/history';

interface HistoryStore extends HistoryState {
  /** Execute a command and add to history */
  executeCommand: (command: Command) => void;
  /** Undo the last command */
  undo: () => void;
  /** Redo the last undone command */
  redo: () => void;
  /** Clear all history */
  clearHistory: () => void;
  /** Check if can undo */
  canUndo: () => boolean;
  /** Check if can redo */
  canRedo: () => boolean;
  /** Get current state summary */
  getHistorySummary: () => { undoCount: number; redoCount: number };
}

const MAX_HISTORY_SIZE = 50;

export const useHistoryStore = create<HistoryStore>((set, get) => ({
  undoStack: [],
  redoStack: [],
  maxHistorySize: MAX_HISTORY_SIZE,
  isExecuting: false,

  executeCommand: (command) => {
    const state = get();

    // Prevent recursive execution
    if (state.isExecuting) return;

    set({ isExecuting: true });

    try {
      // Try to merge with last command
      const lastCommand = state.undoStack[state.undoStack.length - 1];
      if (lastCommand && lastCommand.merge && lastCommand.merge(command)) {
        // Command was merged, re-execute the merged command
        lastCommand.execute();
        set({ isExecuting: false });
        return;
      }

      // Execute the new command
      command.execute();

      // Add to undo stack
      const newUndoStack = [...state.undoStack, command];

      // Limit stack size
      if (newUndoStack.length > state.maxHistorySize) {
        newUndoStack.shift();
      }

      set({
        undoStack: newUndoStack,
        redoStack: [], // Clear redo stack on new action
        isExecuting: false,
      });
    } catch (error) {
      console.error('Failed to execute command:', error);
      set({ isExecuting: false });
    }
  },

  undo: () => {
    const state = get();

    if (state.undoStack.length === 0 || state.isExecuting) return;

    set({ isExecuting: true });

    try {
      const command = state.undoStack[state.undoStack.length - 1];
      command.undo();

      set({
        undoStack: state.undoStack.slice(0, -1),
        redoStack: [...state.redoStack, command],
        isExecuting: false,
      });
    } catch (error) {
      console.error('Failed to undo command:', error);
      set({ isExecuting: false });
    }
  },

  redo: () => {
    const state = get();

    if (state.redoStack.length === 0 || state.isExecuting) return;

    set({ isExecuting: true });

    try {
      const command = state.redoStack[state.redoStack.length - 1];
      command.execute();

      set({
        undoStack: [...state.undoStack, command],
        redoStack: state.redoStack.slice(0, -1),
        isExecuting: false,
      });
    } catch (error) {
      console.error('Failed to redo command:', error);
      set({ isExecuting: false });
    }
  },

  clearHistory: () => {
    set({
      undoStack: [],
      redoStack: [],
    });
  },

  canUndo: () => {
    return get().undoStack.length > 0;
  },

  canRedo: () => {
    return get().redoStack.length > 0;
  },

  getHistorySummary: () => {
    const state = get();
    return {
      undoCount: state.undoStack.length,
      redoCount: state.redoStack.length,
    };
  },
}));