using System;

namespace BaseGames.AI
{
    /// <summary>一条转换：条件型（Condition 非空）或事件型（Event 非空）。二者互斥。</summary>
    public sealed class Transition
    {
        public string Target { get; }
        public Func<IAiContext, bool> Condition { get; }   // 条件型：pull，按 LOD 频率评估
        public AiSignal? Event { get; }                    // 事件型：push，收到信号即触发
        public string Label { get; }                        // 可读标签（显式字符串 / 事件名）

        Transition(string target, Func<IAiContext, bool> condition, AiSignal? evt, string label)
        {
            Target = target;
            Condition = condition;
            Event = evt;
            Label = label;
        }

        public static Transition OnCondition(string target, Func<IAiContext, bool> condition, string label)
            => new Transition(target, condition, null, label);

        public static Transition OnEvent(string target, AiSignal evt)
            => new Transition(target, null, evt, "on " + evt);

        public bool IsEvent => Event.HasValue;
    }
}