using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace Ichni.Editor.Commands
{
    public static class CommandManager
    {
        private static readonly Stack<ICommand> undoStack = new Stack<ICommand>();
        private static readonly Stack<ICommand> redoStack = new Stack<ICommand>();

        /// <summary>
        /// 全局指令拦截与推送入口。任何受撤回保护的修改都应通过此处执行。
        /// </summary>
        public static void ExecuteCommand(ICommand command)
        {
            if (undoStack.Count > 0)
            {
                var topCommand = undoStack.Peek();
                // 尝试拦截短时间内的连续修改并归并为一步
                if (topCommand.TryMerge(command))
                {
                    topCommand.Execute();
                    return;
                }
            }

            // 新操作彻底切断原本可能存在的重做未来
            command.Execute();
            undoStack.Push(command);
            redoStack.Clear(); 
        }

        public static void Undo()
        {
            if (undoStack.Count > 0)
            {
                var command = undoStack.Pop();
                command.Undo();
                redoStack.Push(command);
                Debug.Log("[Command] 执行撤销 (Undo)");
            }
        }

        public static void Redo()
        {
            if (redoStack.Count > 0)
            {
                var command = redoStack.Pop();
                command.Redo();
                undoStack.Push(command);
                Debug.Log("[Command] 执行重做 (Redo)");
            }
        }
    }
}