using UnityEngine;
using BaseGames.World;
using BaseGames.Core.Events;
using BaseGames.Dialogue;

namespace BaseGames.World.Shop
{
    /// <summary>
    /// 商店 NPC 交互组件（架构 15_MapShopModule §2.4）。
    /// 实现 IInteractable；玩家与其交互时先触发招呼对话，对话结束后打开商店面板。
    /// 若无招呼对话，则直接打开商店。
    /// </summary>
    public class ShopNPC : MonoBehaviour, IInteractable
    {
        [Header("组件引用")]
        [SerializeField] private ShopController _shopController;

        [Header("招呼对话（可空，留空则直接开店）")]
        [SerializeField] private DialogueDataSO _greetDialogue;

        [Header("Event Channels")]
        [SerializeField] private DialogueEventChannelSO _dialogueChannel;   // EVT_DialogueStart
        [SerializeField] private VoidEventChannelSO     _onDialogueEnded;   // EVT_DialogueEnded

        [Header("交互提示")]
        [SerializeField] private string _interactPrompt = "购买物品";

        private EventSubscription _greetSub;

        // ── IInteractable ─────────────────────────────────────────────────────

        public bool   CanInteract    => _shopController != null;
        public string InteractPrompt => _interactPrompt;

        public void Interact(Transform player)
        {
            if (_greetDialogue != null && _dialogueChannel != null)
            {
                _greetSub.Dispose();
                _greetSub = _onDialogueEnded.Subscribe(OnGreetDialogueEnded);
                _dialogueChannel.Raise(_greetDialogue);
            }
            else
            {
                OpenShop();
            }
        }

        public void OnPlayerEnterRange(Transform player) { }
        public void OnPlayerExitRange() { }

        // ── 内部 ──────────────────────────────────────────────────────────────

        private void OnGreetDialogueEnded()
        {
            _greetSub.Dispose();
            OpenShop();
        }

        private void OpenShop() => _shopController?.Open();
    }
}