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

public class SongSelectManager : MonoBehaviour
{
    [SerializeField] private Button          tabAllBtn;
    [SerializeField] private Button          tabOwnedBtn;
    [SerializeField] private RectTransform   cardContainer;
    [SerializeField] private SongDetailPanel detailPanel;
    [SerializeField] private DownloadManager downloadManager;
    [SerializeField] private GameObject      loadingOverlay;
    [SerializeField] private GameObject      errorOverlay;
    [SerializeField] private TMP_Text        errorText;


    private static readonly Color TabActiveBg       = new Color(0.05f, 0.82f, 0.95f, 0.42f);
    private static readonly Color TabInactiveBg     = new Color(0.09f, 0.22f, 0.27f, 0.66f);
    private static readonly Color TabActiveText     = new Color(0.92f, 1.0f, 1.0f, 1.0f);
    private static readonly Color TabInactiveText   = new Color(0.72f, 0.86f, 0.90f, 0.82f);
    private static readonly Color TabActiveOutline  = new Color(0.25f, 0.96f, 1.0f, 0.55f);

    private static string CachePath =>
        Path.Combine(Application.persistentDataPath, "songs_cache.json");

    private List<SongInfo>  allSongs     = new List<SongInfo>();
    private bool            showingOwned = false;
    private TMP_FontAsset   _cardFont;

    private void Start()
    {
        // NanumGothic SDF를 직접 로드 — Resources 경로에 있어야 함
        _cardFont = Resources.Load<TMP_FontAsset>("Fonts & Materials/NanumGothic SDF");
        if (_cardFont == null)
            _cardFont = Resources.Load<TMP_FontAsset>("Fonts & Materials/LiberationSans SDF");

        tabAllBtn  .onClick.AddListener(() => SwitchTab(false));
        tabOwnedBtn.onClick.AddListener(() => SwitchTab(true));
        detailPanel.gameObject.SetActive(false);
        SetTabVisual(false);
        FetchSongs();
    }

    private void SwitchTab(bool owned)
    {
        showingOwned = owned;
        SetTabVisual(owned);
        RefreshCards();
    }

    private void SetTabVisual(bool owned)
    {
        ApplyTabStyle(tabAllBtn, !owned);
        ApplyTabStyle(tabOwnedBtn, owned);
    }

    private static void ApplyTabStyle(Button btn, bool active)
    {
        if (btn == null)
            return;

        Color bg = active ? TabActiveBg : TabInactiveBg;
        if (btn.targetGraphic is Image img)
            img.color = bg;

        var colors = btn.colors;
        colors.normalColor = bg;
        colors.highlightedColor = active
            ? new Color(0.10f, 0.95f, 1.0f, 0.58f)
            : new Color(0.14f, 0.34f, 0.40f, 0.72f);
        colors.pressedColor = active
            ? new Color(0.02f, 0.58f, 0.72f, 0.72f)
            : new Color(0.08f, 0.20f, 0.24f, 0.82f);
        colors.selectedColor = colors.highlightedColor;
        colors.disabledColor = new Color(0.05f, 0.10f, 0.12f, 0.45f);
        btn.colors = colors;

        TMP_Text label = btn.GetComponentInChildren<TMP_Text>();
        if (label != null)
            label.color = active ? TabActiveText : TabInactiveText;

        Outline outline = btn.GetComponent<Outline>() ?? btn.gameObject.AddComponent<Outline>();
        outline.enabled = active;
        outline.effectColor = TabActiveOutline;
        outline.effectDistance = new Vector2(0.0f, -0.35f);
    }

    private void FetchSongs()
    {
        loadingOverlay.SetActive(true);
        errorOverlay  .SetActive(false);

        downloadManager.FetchSongsList(
            onSuccess: list =>
            {
                allSongs = list.songs ?? new List<SongInfo>();
                AddLocalForcedRankDummies(allSongs);
                SaveCache(new SongsList { version = list.version, songs = allSongs });
                SongLibrary.Instance.ValidateWithFileSystem(downloadManager, allSongs);
                loadingOverlay.SetActive(false);
                RefreshCards();
            },
            onError: _ =>
            {
                SongsList cached = LoadCache();
                loadingOverlay.SetActive(false);
                if (cached != null)
                {
                    allSongs = cached.songs;
                    RefreshCards();
                }
                else
                {
                    errorOverlay.SetActive(true);
                    errorText.text = "Failed to connect to server\nPlease check your internet connection";
                }
            });
    }

    public void RefreshCards()
    {
        // DestroyImmediate to avoid deferred-destroy interfering with layout
        for (int i = cardContainer.childCount - 1; i >= 0; i--)
            DestroyImmediate(cardContainer.GetChild(i).gameObject);

        List<SongInfo> songs = showingOwned
            ? allSongs.FindAll(s => SongLibrary.Instance.IsSongDownloaded(s.id))
            : allSongs;

        foreach (SongInfo song in songs)
            SpawnCard(song);

        // Order matters: layout first → card gets size → then canvas update → anchored children recalculate
        LayoutRebuilder.ForceRebuildLayoutImmediate(cardContainer);
        Canvas.ForceUpdateCanvases();
    }

    private void SpawnCard(SongInfo song)
    {
        bool downloaded = SongLibrary.Instance.IsSongDownloaded(song.id);

        var card = new GameObject(song.title);
        card.transform.SetParent(cardContainer, false);

        var le = card.AddComponent<LayoutElement>();
        le.preferredHeight = 13f;
        le.flexibleWidth   = 1f;

        var bg = card.AddComponent<Image>();
        bg.color = new Color(1f, 1f, 1f, 0.06f);

        var btn = card.AddComponent<Button>();
        btn.targetGraphic = bg;
        var bc = btn.colors;
        bc.normalColor      = new Color(1f, 1f, 1f, 0.06f);
        bc.highlightedColor = new Color(0.4f, 0.75f, 1f, 0.25f);
        bc.pressedColor     = new Color(0.3f, 0.60f, 0.9f, 0.45f);
        bc.fadeDuration     = 0.1f;
        btn.colors = bc;

        float textLeftInset = downloaded ? 12f : 5f;

        // Title — RectMask2D 컨테이너 안에서 마퀴 스크롤
        var titleMask = new GameObject("TitleMask");
        titleMask.transform.SetParent(card.transform, false);
        var tmr = titleMask.AddComponent<RectTransform>();
        tmr.anchorMin = new Vector2(0f, 0.5f);
        tmr.anchorMax = new Vector2(1f, 1f);
        tmr.offsetMin = new Vector2(textLeftInset, 0f);
        tmr.offsetMax = new Vector2(-3f, 0f);
        titleMask.AddComponent<RectMask2D>();

        var titleGO = new GameObject("Title");
        titleGO.transform.SetParent(titleMask.transform, false);
        var tr = titleGO.AddComponent<RectTransform>();
        tr.anchorMin        = new Vector2(0f, 0f);
        tr.anchorMax        = new Vector2(0f, 1f);
        tr.pivot            = new Vector2(0f, 0.5f);
        tr.anchoredPosition = Vector2.zero;
        tr.sizeDelta        = new Vector2(500f, 0f);
        var tTmp = titleGO.AddComponent<TextMeshProUGUI>();
        if (_cardFont != null) tTmp.font = _cardFont;
        tTmp.text              = song.title;
        tTmp.fontSize          = 5f;
        tTmp.color             = Color.white;
        tTmp.alignment         = TextAlignmentOptions.MidlineLeft;
        tTmp.overflowMode      = TextOverflowModes.Overflow;
        tTmp.textWrappingMode = TextWrappingModes.NoWrap;
        titleGO.AddComponent<MarqueeText>();

        // Artist
        var artistGO = new GameObject("Artist");
        artistGO.transform.SetParent(card.transform, false);
        var ar = artistGO.AddComponent<RectTransform>();
        ar.anchorMin = new Vector2(0f, 0.04f);
        ar.anchorMax = new Vector2(1f, 0.48f);
        ar.offsetMin = new Vector2(textLeftInset, 0f);
        ar.offsetMax = new Vector2(-3f, 0f);
        var aTmp = artistGO.AddComponent<TextMeshProUGUI>();
        if (_cardFont != null) aTmp.font = _cardFont;
        aTmp.text              = song.artist;
        aTmp.fontSize          = 4f;
        aTmp.enableAutoSizing  = true;
        aTmp.fontSizeMin       = 2.8f;
        aTmp.fontSizeMax       = 4f;
        aTmp.color             = new Color(1f, 1f, 1f, 0.6f);
        aTmp.alignment         = TextAlignmentOptions.MidlineLeft;
        aTmp.overflowMode      = TextOverflowModes.Ellipsis;
        aTmp.textWrappingMode  = TextWrappingModes.NoWrap;

        // Downloaded check mark
        if (downloaded)
        {
            var checkGO = new GameObject("OwnedCheck");
            checkGO.transform.SetParent(card.transform, false);
            var cr = checkGO.AddComponent<RectTransform>();
            cr.anchorMin        = new Vector2(0f, 0f);
            cr.anchorMax        = new Vector2(0f, 1f);
            cr.pivot            = new Vector2(0f, 0.5f);
            cr.anchoredPosition = new Vector2(3.0f, 0f);
            cr.sizeDelta        = new Vector2(6f, 0f);

            Color checkColor = new Color(0.36f, 1.0f, 0.58f, 0.95f);
            CreateCheckStroke(checkGO.transform, "ShortStroke", new Vector2(1.8f, 7.1f), new Vector2(1.5f, 0.35f), 42.0f, checkColor);
            CreateCheckStroke(checkGO.transform, "LongStroke", new Vector2(3.25f, 7.85f), new Vector2(3.7f, 0.35f), -45.0f, checkColor);
        }

        SongInfo captured = song;
        btn.onClick.AddListener(() => OnCardClicked(captured));
    }

    private void OnCardClicked(SongInfo song)
    {
        detailPanel.gameObject.SetActive(true);
        detailPanel.Show(song, downloadManager, this);
    }

    private static void CreateCheckStroke(Transform parent, string name, Vector2 anchoredPosition,
        Vector2 size, float rotationZ, Color color)
    {
        var stroke = new GameObject(name);
        stroke.transform.SetParent(parent, false);

        var rect = stroke.AddComponent<RectTransform>();
        rect.anchorMin = new Vector2(0f, 0f);
        rect.anchorMax = new Vector2(0f, 0f);
        rect.pivot = new Vector2(0.5f, 0.5f);
        rect.anchoredPosition = anchoredPosition;
        rect.sizeDelta = size;
        rect.localRotation = Quaternion.Euler(0f, 0f, rotationZ);

        var img = stroke.AddComponent<Image>();
        img.color = color;
        img.raycastTarget = false;
    }

    private static void SaveCache(SongsList list)
    {
        try { File.WriteAllText(CachePath, JsonUtility.ToJson(list, true)); }
        catch { }
    }

    private static SongsList LoadCache()
    {
        if (!File.Exists(CachePath)) return null;
        try { return JsonUtility.FromJson<SongsList>(File.ReadAllText(CachePath)); }
        catch { return null; }
    }

    private static void AddLocalForcedRankDummies(List<SongInfo> songs)
    {
        string root = Path.Combine(Application.persistentDataPath, "beatsaber");
        AddLocalForcedRankDummy(songs, root, "dummy_rank_m", "M", 10);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_splus", "S+", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_s", "S", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_a", "A", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_b", "B", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_c", "C", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_d", "D", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_f", "F", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_splus_border", "S+ 98%", 100);
        AddLocalForcedRankDummy(songs, root, "dummy_rank_f_zero", "F 0%", 20);
    }

    private static void AddLocalForcedRankDummy(List<SongInfo> songs, string root, string id, string title, int noteCount)
    {
        if (songs.Exists(song => song.id == id))
            return;

        string songDir = Path.Combine(root, id);
        string audioPath = Path.Combine(songDir, $"{id}.mp3");
        string mapFile = $"Map_{id}_forced.json";
        string mapPath = Path.Combine(songDir, mapFile);
        if (!File.Exists(audioPath) || !File.Exists(mapPath))
            return;

        long audioSize = new FileInfo(audioPath).Length;
        long mapSize = new FileInfo(mapPath).Length;
        DifficultyInfo info = new DifficultyInfo
        {
            mapFile = mapFile,
            mapSize = mapSize,
            noteCount = noteCount
        };

        songs.Insert(0, new SongInfo
        {
            id = id,
            title = title,
            artist = "Forced Rank Dummy",
            bpm = 120.0f,
            duration = 1,
            audioFile = $"dummy/{id}.mp3",
            audioSize = audioSize,
            coverImage = "",
            difficulties = new DifficultyMap
            {
                normal = info,
                hard = info,
                expert = info,
                expertplus = info
            },
            addedAt = "2026-05-29"
        });
    }
}