using System.Collections.Generic;
using Cielonos.Core.Interaction;
using Cielonos.MainGame.UI;
using SLSUtilities.UI;
using UnityEngine;

namespace Cielonos.MainGame.Characters
{
    public class PlayerInteractionSubcontroller : SubcontrollerBase<Player>
    {
        public Player player => owner;

        /// <summary>当前进入触发区的所有交互选项（由 InteractionTrigger 维护）。</summary>
        public List<InteractionChoice> currentChoices = new List<InteractionChoice>();

        /// <summary>当前高亮（选中）的选项索引。</summary>
        public int currentChoiceIndex { get; private set; }

        /// <summary>当前激活的可交互对象（最近一次进入触发区的对象）。</summary>
        public InteractableObjectBase currentInteractable { get; private set; }

        /// <summary>
        /// 当有 UIPage 打开时为 true，此时交互 UI 被挂起、交互操作被屏蔽。
        /// </summary>
        private bool _isSuspended;

        public override void Initialize()
        {
            base.Initialize();
            player.operationSc.OnInteract += ExecuteCurrentChoice;
            player.operationSc.OnNavigateInteractionChoice += NavigateChoice;

            // 订阅 UIPageManager 的输入阻塞事件，联动 InteractionUIArea 的显隐
            if (UIPageManager.Instance != null)
            {
                UIPageManager.Instance.OnInputBlockChanged += OnUIInputBlockChanged;
            }
        }

        private void OnDestroy()
        {
            if (UIPageManager.Instance != null)
            {
                UIPageManager.Instance.OnInputBlockChanged -= OnUIInputBlockChanged;
            }
        }

        // ====================================================================
        // UIPage 联动
        // ====================================================================

        /// <summary>
        /// 当任何 UIPage 打开/关闭时由 UIPageManager 触发。
        /// blocked = true：有 UIPage 打开 → 挂起 InteractionUIArea（隐藏但不清除状态）。
        /// blocked = false：所有 UIPage 关闭 → 若仍在交互范围内则恢复显示。
        /// </summary>
        private void OnUIInputBlockChanged(bool blocked)
        {
            _isSuspended = blocked;

            if (blocked)
            {
                // 仅隐藏 UI，不清除 currentInteractable / currentChoices
                PlayerCanvas.InteractionUIArea?.Hide();
            }
            else
            {
                // 所有页面关闭后，若仍在交互范围内，恢复 InteractionUIArea
                if (currentInteractable != null && currentChoices.Count > 0)
                {
                    PlayerCanvas.InteractionUIArea?.Show(currentChoices, currentChoiceIndex);
                }
            }
        }

        // ====================================================================
        // 进入 / 离开触发区
        // ====================================================================

        /// <summary>由 InteractionTrigger 在进入触发区时调用，记录当前激活对象并显示选项 UI。</summary>
        public void SetCurrentInteractable(InteractableObjectBase interactable)
        {
            currentInteractable = interactable;
            currentChoiceIndex = 0;

            // 自动跳到第一个可用的选项
            SnapToFirstInteractable();

            // 若当前没有 UIPage 打开，才显示交互选项
            if (!_isSuspended)
            {
                PlayerCanvas.InteractionUIArea?.Show(currentChoices, currentChoiceIndex);
            }
        }

        /// <summary>由 InteractionTrigger 在退出触发区时调用，清除当前激活对象并隐藏选项 UI。</summary>
        public void RemoveCurrentInteractable(InteractableObjectBase interactable)
        {
            if (currentInteractable != interactable) return;

            currentInteractable = null;
            PlayerCanvas.InteractionUIArea?.Hide();
        }

        // ====================================================================
        // 导航与执行
        // ====================================================================

        /// <summary>
        /// 导航选中索引。delta = 1（向下/滚轮向下），delta = -1（向上/滚轮向上）。
        /// 会自动跳过 isInteractable = false 的选项。
        /// 若处于挂起状态（有 UIPage 打开），忽略导航。
        /// </summary>
        public void NavigateChoice(int delta)
        {
            if (_isSuspended) return;
            if (currentChoices.Count == 0) return;

            int startIndex = currentChoiceIndex;
            int next = currentChoiceIndex;

            do
            {
                next = (next + delta + currentChoices.Count) % currentChoices.Count;
                if (next == startIndex) break; // 绕了一圈，无可用选项，保持原位
            }
            while (!currentChoices[next].isInteractable);

            currentChoiceIndex = next;
            PlayerCanvas.InteractionUIArea?.UpdateHighlight(currentChoiceIndex);
        }

        /// <summary>
        /// 执行当前高亮的选项。若该选项 isInteractable = false 或处于挂起状态，则什么都不做。
        /// </summary>
        public void ExecuteCurrentChoice()
        {
            if (_isSuspended) return;
            if (currentChoices.Count == 0) return;
            if (currentChoiceIndex < 0 || currentChoiceIndex >= currentChoices.Count) return;

            InteractionChoice choice = currentChoices[currentChoiceIndex];
            if (!choice.isInteractable)
            {
                Debug.Log($"[InteractionSc] 选项 '{choice.choiceName}' 当前不可用。");
                return;
            }

            choice.action?.Invoke();
        }

        // ====================================================================
        // 内部工具
        // ====================================================================

        /// <summary>将 currentChoiceIndex 移到第一个 isInteractable = true 的选项。</summary>
        private void SnapToFirstInteractable()
        {
            if (currentChoices.Count == 0) return;

            for (int i = 0; i < currentChoices.Count; i++)
            {
                int index = (currentChoiceIndex + i) % currentChoices.Count;
                if (currentChoices[index].isInteractable)
                {
                    currentChoiceIndex = index;
                    return;
                }
            }
            // 所有选项均不可用时，停在 0
            currentChoiceIndex = 0;
        }
    }
}