using System.Collections.Generic;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace AibisDream.UI.Terminal
{
    public class TerminalChapterPanel : MonoBehaviour, IUIPanel
    {
        [SerializeField] private TerminalPanelAnimator panelAnimator;
        [SerializeField] private TerminalHeaderView header;
        [SerializeField] private TerminalChapterItemView leftPreview;
        [SerializeField] private TerminalChapterItemView currentView;
        [SerializeField] private TerminalChapterItemView rightPreview;
        [SerializeField] private TMP_Text emptyText;
        [SerializeField] private TMP_Text selectedTitleText;
        [SerializeField] private Button previousButton;
        [SerializeField] private Button nextButton;
        [SerializeField] private Button continueButton;
        [SerializeField] private Button restartButton;
        [SerializeField] private Button backButton;

        private readonly List<ChapterVo> _chapters = new List<ChapterVo>();
        private int _currentIndex;

        public bool IsOpen => gameObject.activeSelf;
        public bool IsCloseable => true;

        private void Awake()
        {
            previousButton?.onClick.AddListener(Previous);
            nextButton?.onClick.AddListener(Next);
            continueButton?.onClick.AddListener(Continue);
            restartButton?.onClick.AddListener(Restart);
            backButton?.onClick.AddListener(Close);
        }

        private void OnDestroy()
        {
            previousButton?.onClick.RemoveListener(Previous);
            nextButton?.onClick.RemoveListener(Next);
            continueButton?.onClick.RemoveListener(Continue);
            restartButton?.onClick.RemoveListener(Restart);
            backButton?.onClick.RemoveListener(Close);
        }

        public void Show()
        {
            header?.SetText("<选择章节>", string.Empty);
            LoadChapters();
            RefreshViews();
            if (panelAnimator != null)
            {
                panelAnimator.Show();
            }
            else
            {
                gameObject.SetActive(true);
            }
        }

        public void Hide()
        {
            if (panelAnimator != null)
            {
                panelAnimator.Hide();
            }
            else
            {
                gameObject.SetActive(false);
            }
        }

        public void Close()
        {
            UIManager.Instance.HidePreferredChapterPanel();
        }

        private void LoadChapters()
        {
            _chapters.Clear();
            var chapters = ChapterController.Instance.GetChapterList();
            _chapters.AddRange(chapters);
            _currentIndex = Mathf.Clamp(_currentIndex, 0, Mathf.Max(0, _chapters.Count - 1));
        }

        private void RefreshViews()
        {
            var hasChapters = _chapters.Count > 0;
            if (emptyText != null)
            {
                emptyText.gameObject.SetActive(!hasChapters);
            }

            SetViewActive(leftPreview, hasChapters && _chapters.Count > 1);
            SetViewActive(currentView, hasChapters);
            SetViewActive(rightPreview, hasChapters && _chapters.Count > 1);

            if (!hasChapters)
            {
                if (selectedTitleText != null)
                {
                    selectedTitleText.text = "NO CHAPTER DATA";
                }

                continueButton?.gameObject.SetActive(false);
                restartButton?.gameObject.SetActive(false);
                return;
            }

            var current = _chapters[_currentIndex];
            currentView?.Init(current, selected: true, preview: false);
            leftPreview?.Init(_chapters[LoopIndex(_currentIndex - 1)], selected: false, preview: true);
            rightPreview?.Init(_chapters[LoopIndex(_currentIndex + 1)], selected: false, preview: true);

            if (selectedTitleText != null)
            {
                selectedTitleText.text = current.title;
            }

            continueButton?.gameObject.SetActive(current.hasSaveFile);
            restartButton?.gameObject.SetActive(true);
        }

        private static void SetViewActive(TerminalChapterItemView view, bool active)
        {
            if (view != null)
            {
                view.gameObject.SetActive(active);
            }
        }

        private int LoopIndex(int index)
        {
            if (_chapters.Count == 0)
            {
                return 0;
            }

            return (index + _chapters.Count) % _chapters.Count;
        }

        private void Previous()
        {
            if (_chapters.Count == 0)
            {
                return;
            }

            _currentIndex = LoopIndex(_currentIndex - 1);
            RefreshViews();
        }

        private void Next()
        {
            if (_chapters.Count == 0)
            {
                return;
            }

            _currentIndex = LoopIndex(_currentIndex + 1);
            RefreshViews();
        }

        private void Continue()
        {
            if (_chapters.Count == 0 || !_chapters[_currentIndex].hasSaveFile)
            {
                return;
            }

            ChapterController.Instance.StartWithSaveFile();
            Close();
        }

        private void Restart()
        {
            if (_chapters.Count == 0)
            {
                return;
            }

            ChapterController.Instance.StartWithChapter(_chapters[_currentIndex]);
            Close();
        }
    }
}