using Ichni.Story.Dialogue;
using Ichni.UI;
using UnityEngine;
using UnityEngine.Events;

namespace Ichni.Story.UI
{
    /// <summary>
    /// 对话系统专用的 UI 页面容器。
    /// 接管整个对话面板的淡入淡出及交互状态控制，
    /// 将显示生命周期与对话流逻辑 (VNDialoguePresenter) 彻底解耦。
    /// </summary>
    public class DialogUIPage : UIPageBase
    {
        public static DialogUIPage instance;

        [Header("立绘舞台")]
        public VNPortraitStage portraitStage;

        [Header("台词区")]
        public TMPro.TextMeshProUGUI dialogueText;
        public GameObject speakerContainer;
        public TMPro.TextMeshProUGUI speakerText;

        [Header("推进按钮")]
        public UnityEngine.UI.Button advanceButton;
        [Tooltip("点击后自动快进；已记忆选项会自动跨过，遇到需要玩家选择的新选项时停止。")]
        public UnityEngine.UI.Button fastForwardButton;

        [Header("对话辅助功能")]
        [Tooltip("中途退出当前 TextBlock；本次尚未完成的选项、变量和进度会恢复到进入前状态。")]
        [SerializeField] private UnityEngine.UI.Button backButton;

        [Tooltip("打开当前一次 TextBlock 的临时对话记录。")]
        [SerializeField] private UnityEngine.UI.Button showHistoryButton;

        [Tooltip("覆盖在对话上方的记录面板；它不是独立 UIPage。")]
        [SerializeField] private DialogueHistoryPage dialogueHistoryPage;

        [Header("选项区")]
        public GameObject choiceFrame;
        public ChoiceButton[] choiceButtons = new ChoiceButton[4];

        [Header("动态组件")]
        public DialogWheel dialogWheel;
        
        protected override void Awake()
        {
            base.Awake();
            
            if (instance == null)
            {
                instance = this;
            }
            else
            {
                Destroy(gameObject);
                return;
            }
            
            // 默认启动时强制隐藏
            if (mainCanvasGroup != null)
            {
                mainCanvasGroup.alpha = 0f;
                mainCanvasGroup.interactable = false;
                mainCanvasGroup.blocksRaycasts = false;
                mainCanvasGroup.gameObject.SetActive(false);
            }
        }

        private void Start()
        {
            if (backButton != null)
                backButton.onClick.AddListener(OnBackButtonClicked);

            if (showHistoryButton != null)
                showHistoryButton.onClick.AddListener(OnShowHistoryButtonClicked);
        }

        private void OnDestroy()
        {
            if (backButton != null)
                backButton.onClick.RemoveListener(OnBackButtonClicked);

            if (showHistoryButton != null)
                showHistoryButton.onClick.RemoveListener(OnShowHistoryButtonClicked);

            if (instance == this)
                instance = null;
        }

        public void PlayFadeIn(UnityAction onComplete = null)
        {
            FadeIn(0.2f, false, onComplete);
        }

        public void PlayFadeOut(UnityAction onComplete = null)
        {
            FadeOut(0.2f, false, onComplete);
        }

        private void OnBackButtonClicked()
        {
            // History 覆盖层本身会拦截输入；此处额外保护，避免错误配置导致 Back 穿透到底层对话。
            if (dialogueHistoryPage != null && dialogueHistoryPage.IsOpen)
                return;

            StoryDialogueController.instance?.CancelActiveDialogue();
        }

        private void OnShowHistoryButtonClicked()
        {
            if (dialogueHistoryPage == null || dialogueHistoryPage.IsOpen)
                return;

            // 打开记录不会推进 Yarn；仅取消快进并补全正在显示的一句，避免记录与画面不同步。
            StoryDialogueController.instance?.dialogueRunner
                ?.GetComponent<VNDialoguePresenter>()
                ?.PrepareForHistory();
            dialogueHistoryPage.Open(DialogueHistory.Entries);
        }
    }
}