using System;
using System.Collections.Generic;
using Cielonos.MainGame.Inventory;
using Sirenix.OdinInspector;
using SLSUtilities.UI;
using UnityEngine;
using UnityEngine.UI;

namespace Cielonos.MainGame.UI
{
    /// <summary>
    /// 机械台 UI 页面。
    /// 左侧为可选装备列表（Selector），右侧为物品详情面板（ItemDetailPanel）。
    /// 玩家点击列表条目选中物品，点击 Confirm 确认获取。
    /// </summary>
    public class MechanicalTableUIPage : UIPageBase
    {
        [Title("Selectors")]
        public GameObject selectorPrefab;
        public RectTransform selectorContainer;
        public List<MechanicalTableSelector> selectors = new List<MechanicalTableSelector>();

        [Title("Detail Panel")]
        public ItemDetailPanel itemDetailPanel;

        [Title("Buttons")]
        public Button confirmButton;
        public Button closeButton;

        private MechanicalTableSelector currentSelected;
        private Action<int> onConfirmCallback;
        private Action onSkipCallback;

        /// <summary>当前选中的 Selector 索引，-1 表示未选中。</summary>
        public int SelectedIndex => currentSelected != null ? selectors.IndexOf(currentSelected) : -1;

        protected override void Start()
        {
            base.Start();

            if (confirmButton != null)
            {
                confirmButton.onClick.AddListener(OnConfirmClicked);
            }

            if (closeButton != null)
            {
                closeButton.onClick.AddListener(OnCloseClicked);
            }
        }

        /// <summary>
        /// 用物品预制体列表填充选择器，并注册确认回调。
        /// 每次调用会清除旧选择器并重新生成。
        /// </summary>
        /// <param name="items">物品候选列表。奖励系统统一以 ItemBase 作为候选数据。</param>
        /// <param name="onConfirm">玩家点击 Confirm 后的回调，参数为选中的物品索引。</param>
        public void SetOffers(List<ItemBase> items, Action<int> onConfirm)
        {
            SetOffers(items, onConfirm, null);
        }

        public void SetOffers(List<ItemBase> items, Action<int> onConfirm, Action onSkip)
        {
            onConfirmCallback = onConfirm;
            onSkipCallback = onSkip;

            ClearSelectors();

            if (items == null) return;

            for (int i = 0; i < items.Count; i++)
            {
                ItemBase item = items[i];
                if (item == null)
                {
                    continue;
                }

                MechanicalTableSelector selector = CreateSelector();
                if (selector != null)
                {
                    selector.Setup(item);
                }
            }

            // 重置选中状态
            currentSelected = null;
            RefreshConfirmButton();

            // 详情面板默认隐藏
            if (itemDetailPanel != null)
            {
                itemDetailPanel.ClearPanel();
            }
        }

        /// <summary>
        /// 由 MechanicalTableSelector 调用，选中指定的选择器。
        /// </summary>
        public void SelectItem(MechanicalTableSelector selector)
        {
            if (selector == null || !selectors.Contains(selector)) return;

            // 取消上一个选中
            if (currentSelected != null)
            {
                currentSelected.SetSelected(false);
            }

            // 设置新选中
            currentSelected = selector;
            currentSelected.SetSelected(true);

            // 更新详情面板
            if (itemDetailPanel != null)
            {
                itemDetailPanel.SetItem(currentSelected.item);
            }

            // 启用确认按钮
            RefreshConfirmButton();
        }

        protected override void OnPageOpened()
        {
            RefreshConfirmButton();
        }

        protected override void OnPageClosed()
        {
            currentSelected = null;
            onConfirmCallback = null;
            onSkipCallback = null;
        }

        private void OnConfirmClicked()
        {
            if (currentSelected == null) return;

            int index = SelectedIndex;
            if (index < 0) return;

            // 先缓存回调，因为 Close() 会清除引用
            Action<int> callback = onConfirmCallback;
            Close();
            callback?.Invoke(index);
        }

        private void OnCloseClicked()
        {
            Action callback = onSkipCallback;
            Close();
            callback?.Invoke();
        }

        private MechanicalTableSelector CreateSelector()
        {
            if (selectorPrefab == null || selectorContainer == null)
            {
                Debug.LogError("[MechanicalTableUIPage] selectorPrefab 或 selectorContainer 未配置。");
                return null;
            }

            GameObject obj = Instantiate(selectorPrefab, selectorContainer);
            MechanicalTableSelector selector = obj.GetComponent<MechanicalTableSelector>();
            if (selector == null)
            {
                Debug.LogError("[MechanicalTableUIPage] selectorPrefab 缺少 MechanicalTableSelector 组件。");
                Destroy(obj);
                return null;
            }

            selectors.Add(selector);
            return selector;
        }

        private void ClearSelectors()
        {
            foreach (MechanicalTableSelector selector in selectors)
            {
                if (selector != null)
                {
                    Destroy(selector.gameObject);
                }
            }

            selectors.Clear();
            currentSelected = null;
        }

        private void RefreshConfirmButton()
        {
            if (confirmButton != null)
            {
                confirmButton.interactable = currentSelected != null;
            }
        }
    }
}