using System;
using System.Threading;
using System.Threading.Tasks;
using Febucci.UI.Core;
using UnityEngine;
using AibisDream.Utility;
using AibisDream.Framework;

namespace AibisDream
{
    public class CenterText : MonoBehaviour, ILineView
    {
        [SerializeField] private TypewriterCore content;
        [SerializeField] private GameObject box;

        private CancellationTokenSource _autoHideToken;
        private event Action OnTextShowed;

        // ---------------------------- 显示逻辑 ----------------------------

        public void RunLine(LineSyncToken syncToken)
        {
            // 先中断结束事件
            _autoHideToken?.Cancel();
            _autoHideToken = null;
            OnTextShowed = null;

            // 先停止旧动画并准备好激活状态，避免 OnEnable 或旧动画完成事件命中新 token。
            content.StopShowingText();
            box.SetActive(true);
            content.StopShowingText();
            content.TextAnimator.SetText(string.Empty);

            // 注册事件
            OnTextShowed += syncToken.TextShown;
            syncToken.SkipTextAnima += () => content.SkipTypewriter();
            syncToken.OnAdvance += AfterAdvance;

            // 播放文字
            ApplyTextSpeedSnapshot();
            syncToken.TextStart();
            content.ShowText(syncToken.lineInfo.lineText);
        }

        private void ApplyTextSpeedSnapshot()
        {
            content.resetTypingSpeedAtStartup = false;
            content.SetTypewriterSpeed(TextSpeedSettings.CurrentMultiplier);
        }

        private async void AfterAdvance()
        {
            _autoHideToken = new CancellationTokenSource();
            try
            {
                await Task.Delay(ConstRef.AutoHideDelay, _autoHideToken.Token);
                HideDialog();
            }
            catch (TaskCanceledException)
            {
                // 忽略取消
            }
        }

        public void HideDialog()
        {
            box.SetActive(false);
        }


        // ---------------------------- 生命周期 ----------------------------

        private void Awake()
        {
            box.SetActive(false);
        }

        private void Start()
        {
            DialogUIManager.Instance.RegisterScreenView(DialogViewType.CenterText, this);
            RegisterEvents();
        }

        private void OnDestroy()
        {
            DialogUIManager.Instance.UnRegisterScreenView(DialogViewType.CenterText);
            UnregisterEvents();
            OnTextShowed = null;
        }

        private void RegisterEvents()
        {
            // 全局事件
            EnumEventSystem.Global.Register(DialogEventEnum.OptionShow, OnOptionShow);

            // 文本事件
            content.onTextShowed.AddListener(TextShowed);
        }

        private void UnregisterEvents()
        {
            // 全局事件
            EnumEventSystem.Global.UnRegister(DialogEventEnum.OptionShow, OnOptionShow);

            // 文本事件
            content.onTextShowed.RemoveListener(TextShowed);
        }

        private void TextShowed()
        {
            OnTextShowed?.Invoke();
            OnTextShowed = null;
        }

        private void OnOptionShow()
        {
            _autoHideToken?.Cancel();
            _autoHideToken = null;

            HideDialog();
        }
    }
}