import type { Command } from "./command";
import { commandIds } from "./ids";

export const historyUndoCommand: Command = {
  id: commandIds.historyUndo,
  name: "Undo",
  execute({ state }) {
    const previous = state.history.past.at(-1);
    if (!previous) return state;

    return {
      ...state,
      document: previous.document,
      editor: previous.editor,
      history: {
        past: state.history.past.slice(0, -1),
        future: [{ document: state.document, editor: state.editor }, ...state.history.future],
      },
    };
  },
};

export const historyRedoCommand: Command = {
  id: commandIds.historyRedo,
  name: "Redo",
  execute({ state }) {
    const next = state.history.future[0];
    if (!next) return state;

    return {
      ...state,
      document: next.document,
      editor: next.editor,
      history: {
        past: [...state.history.past, { document: state.document, editor: state.editor }],
        future: state.history.future.slice(1),
      },
    };
  },
};

export const historyCommands = [historyUndoCommand, historyRedoCommand] satisfies Command<unknown>[];