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

public class SongDetailPanel : MonoBehaviour
{
    [Header("곡 정보")]
    [SerializeField] private TMP_Text titleText;
    [SerializeField] private TMP_Text artistText;
    [SerializeField] private TMP_Text infoText;

    [Header("난이도 버튼")]
    [SerializeField] private Button btnNormal;
    [SerializeField] private Button btnHard;
    [SerializeField] private Button btnExpert;
    [SerializeField] private Button btnExpertPlus;

    [Header("액션 버튼")]
    [SerializeField] private Button downloadButton;
    [SerializeField] private Button deleteButton;
    [SerializeField] private Button playButton;
    [SerializeField] private Button closeButton;

    [Header("진행률")]
    [SerializeField] private GameObject progressGroup;
    [SerializeField] private Slider     progressSlider;
    [SerializeField] private TMP_Text   progressText;

    [Header("씬 이름")]
    [SerializeField] private string gameSceneName = "Game";

    private static readonly Color NeonBg         = new Color(0.05f, 0.82f, 0.95f, 0.42f);
    private static readonly Color DarkButtonBg   = new Color(0.09f, 0.22f, 0.27f, 0.66f);
    private static readonly Color DisabledBg     = new Color(0.06f, 0.12f, 0.15f, 0.48f);
    private static readonly Color DangerBg       = new Color(0.52f, 0.16f, 0.22f, 0.72f);
    private static readonly Color ButtonText     = new Color(0.92f, 1.0f, 1.0f, 1.0f);
    private static readonly Color MutedText      = new Color(0.66f, 0.80f, 0.84f, 0.76f);
    private static readonly Color NeonOutline    = new Color(0.25f, 0.96f, 1.0f, 0.42f);

    private SongInfo          currentSong;
    private string            selectedDifficulty;
    private DownloadManager   downloadManager;
    private SongSelectManager selectManager;
    private MarqueeText       titleMarquee;
    private MarqueeText       artistMarquee;

    private readonly (string key, Func<SongDetailPanel, Button> btn)[] diffSlots =
    {
        ("normal",     p => p.btnNormal),
        ("hard",       p => p.btnHard),
        ("expert",     p => p.btnExpert),
        ("expertplus", p => p.btnExpertPlus),
    };

    private void Awake()
    {
        HideDifficultyLabel();
        titleMarquee = ConfigureMarqueeText(titleText, 5.0f, 7.2f);
        artistMarquee = ConfigureMarqueeText(artistText, 3.4f, 4.4f);
        ConfigureOneLineText(infoText, 3.2f, 4.2f, TextAlignmentOptions.MidlineLeft);
        ConfigureButtonText(btnNormal, 3.2f, 4.0f);
        ConfigureButtonText(btnHard, 3.2f, 4.0f);
        ConfigureButtonText(btnExpert, 3.2f, 4.0f);
        ConfigureButtonText(btnExpertPlus, 3.0f, 3.8f);
        ConfigureButtonText(downloadButton, 3.5f, 4.4f);
        ConfigureButtonText(deleteButton, 3.5f, 4.4f);
        ConfigureButtonText(playButton, 3.5f, 4.4f);
        ConfigureButtonText(closeButton, 5.2f, 6.4f);
    }

    // ── Public API ───────────────────────────────────────────

    public void Show(SongInfo song, DownloadManager dm, SongSelectManager sm)
    {
        currentSong        = song;
        downloadManager    = dm;
        selectManager      = sm;
        selectedDifficulty = null;

        titleText.text  = song.title;
        artistText.text = song.artist;
        infoText.text   = song.duration > 0
            ? $"BPM {Mathf.RoundToInt(song.bpm)}  {FormatDuration(song.duration)}"
            : $"BPM {Mathf.RoundToInt(song.bpm)}";

        titleMarquee?.Refresh();
        artistMarquee?.Refresh();
        RefreshUI();
    }

    // ── UI 갱신 ──────────────────────────────────────────────

    private void RefreshUI()
    {
        bool downloaded = SongLibrary.Instance.IsSongDownloaded(currentSong.id);

        foreach (var (key, getBtn) in diffSlots)
        {
            Button btn    = getBtn(this);
            bool   exists = currentSong.difficulties.Get(key) != null;

            btn.interactable = downloaded && exists;
            btn.onClick.RemoveAllListeners();

            if (downloaded && exists)
            {
                string captured = key;
                btn.onClick.AddListener(() => SelectDifficulty(captured));
            }
        }

        UpdateDiffColors();

        downloadButton.gameObject.SetActive(!downloaded);
        deleteButton.gameObject.SetActive(downloaded);
        downloadButton.interactable = !downloaded;
        deleteButton.interactable = downloaded;
        playButton.interactable = downloaded && selectedDifficulty != null;
        progressGroup.SetActive(false);
        UpdateActionButtonStyles(downloaded);

        downloadButton.onClick.RemoveAllListeners();
        downloadButton.onClick.AddListener(OnDownloadClicked);

        deleteButton.onClick.RemoveAllListeners();
        deleteButton.onClick.AddListener(OnDeleteClicked);

        playButton.onClick.RemoveAllListeners();
        playButton.onClick.AddListener(OnPlayClicked);

        if (closeButton != null)
        {
            closeButton.onClick.RemoveAllListeners();
            closeButton.onClick.AddListener(() => gameObject.SetActive(false));
        }
    }

    private void SelectDifficulty(string difficulty)
    {
        selectedDifficulty      = difficulty;
        playButton.interactable = true;
        UpdateDiffColors();
        UpdateActionButtonStyles(true);
    }

    private void UpdateDiffColors()
    {
        foreach (var (key, getBtn) in diffSlots)
        {
            Button btn      = getBtn(this);
            bool   selected = key == selectedDifficulty;

            ApplyButtonStyle(btn, selected ? NeonBg : DarkButtonBg, selected, btn.interactable, false);
        }
    }

    // ── 다운로드 ──────────────────────────────────────────────

    private void OnDownloadClicked()
    {
        StartCoroutine(DownloadAllCoroutine());
    }

    private IEnumerator DownloadAllCoroutine()
    {
        var diffs = new List<string>();
        foreach (var (key, _) in diffSlots)
            if (currentSong.difficulties.Get(key) != null)
                diffs.Add(key);

        if (diffs.Count == 0) yield break;

        SetInteractable(false);
        progressGroup.SetActive(true);
        downloadButton.gameObject.SetActive(false);
        deleteButton.gameObject.SetActive(false);
        playButton.gameObject.SetActive(false);

        int  totalSteps = diffs.Count;
        int  doneSteps  = 0;
        bool failed     = false;

        foreach (string diff in diffs)
        {
            bool stepDone = false;

            downloadManager.DownloadSong(
                currentSong, diff,
                onProgress: p =>
                {
                    float overall        = (doneSteps + p) / totalSteps;
                    progressSlider.value = overall;
                    progressText.text    = $"{diffs[Mathf.Min(doneSteps, diffs.Count - 1)].ToUpper()}  {(int)(overall * 100)}%";
                },
                onComplete: () =>
                {
                    SongLibrary.Instance.MarkDownloaded(currentSong.id, diff);
                    doneSteps++;
                    stepDone = true;
                },
                onError: err =>
                {
                    Debug.LogError($"[SongDetailPanel] {err}");
                    failed   = true;
                    stepDone = true;
                });

            yield return new WaitUntil(() => stepDone);
            if (failed) break;
        }

        SetInteractable(true);
        progressGroup.SetActive(false);
        playButton.gameObject.SetActive(true);
        selectManager.RefreshCards();
        RefreshUI();

        if (!failed)
            Debug.Log($"[SongDetailPanel] '{currentSong.title}' 전체 다운로드 완료");
    }

    // ── 삭제 ─────────────────────────────────────────────────

    private void OnDeleteClicked()
    {
        downloadManager.DeleteSong(currentSong.id);
        SongLibrary.Instance.MarkSongRemoved(currentSong.id);
        selectedDifficulty = null;
        selectManager.RefreshCards();
        RefreshUI();
    }

    // ── 플레이 ───────────────────────────────────────────────

    private void OnPlayClicked()
    {
        GameSession.SelectedSong       = currentSong;
        GameSession.SelectedDifficulty = selectedDifficulty;
        SceneManager.LoadScene(gameSceneName);
    }

    // ── 유틸 ─────────────────────────────────────────────────

    private void SetInteractable(bool value)
    {
        downloadButton.interactable = value;
        deleteButton.interactable   = value;
        playButton.interactable     = value && selectedDifficulty != null;
        foreach (var (_, getBtn) in diffSlots)
            getBtn(this).interactable = value;
    }

    private static string FormatDuration(int seconds)
        => $"{seconds / 60}:{seconds % 60:D2}";

    private void HideDifficultyLabel()
    {
        Transform label = transform.Find("LblDifficulty");
        if (label != null)
            label.gameObject.SetActive(false);
    }

    private void UpdateActionButtonStyles(bool downloaded)
    {
        ApplyButtonStyle(downloadButton, NeonBg, true, !downloaded, false);
        ApplyButtonStyle(deleteButton, DangerBg, true, downloaded, true);
        ApplyButtonStyle(playButton, NeonBg, true, playButton.interactable, false);
        ApplyButtonStyle(closeButton, DarkButtonBg, false, true, false);
    }

    private static void ApplyButtonStyle(Button btn, Color activeBg, bool outlined, bool enabled, bool danger)
    {
        if (btn == null)
            return;

        Color bg = enabled ? activeBg : DisabledBg;
        if (btn.targetGraphic is Image img)
            img.color = bg;

        var colors = btn.colors;
        colors.normalColor = bg;
        colors.highlightedColor = enabled
            ? (danger ? new Color(0.72f, 0.23f, 0.30f, 0.86f) : new Color(0.10f, 0.95f, 1.0f, 0.58f))
            : DisabledBg;
        colors.pressedColor = enabled
            ? (danger ? new Color(0.42f, 0.10f, 0.15f, 0.92f) : new Color(0.02f, 0.58f, 0.72f, 0.80f))
            : DisabledBg;
        colors.selectedColor = colors.highlightedColor;
        colors.disabledColor = DisabledBg;
        colors.fadeDuration = 0.08f;
        btn.colors = colors;

        TMP_Text label = btn.GetComponentInChildren<TMP_Text>();
        if (label != null)
            label.color = enabled ? ButtonText : MutedText;

        Outline outline = btn.GetComponent<Outline>() ?? btn.gameObject.AddComponent<Outline>();
        outline.enabled = outlined && enabled;
        outline.effectColor = danger ? new Color(1.0f, 0.35f, 0.42f, 0.34f) : NeonOutline;
        outline.effectDistance = new Vector2(0.0f, -0.28f);
    }

    private static MarqueeText ConfigureMarqueeText(TMP_Text text, float minSize, float maxSize)
    {
        if (text == null)
            return null;

        RectTransform textRect = text.rectTransform;
        Transform originalParent = textRect.parent;
        int siblingIndex = textRect.GetSiblingIndex();
        string maskName = $"{text.name}Mask";
        Transform existingMask = originalParent != null ? originalParent.Find(maskName) : null;
        RectTransform maskRect;

        if (existingMask != null)
        {
            maskRect = existingMask as RectTransform;
            if (textRect.parent != existingMask)
                textRect.SetParent(existingMask, false);
        }
        else
        {
            var mask = new GameObject(maskName);
            mask.transform.SetParent(originalParent, false);
            mask.transform.SetSiblingIndex(siblingIndex);
            maskRect = mask.AddComponent<RectTransform>();
            maskRect.anchorMin = textRect.anchorMin;
            maskRect.anchorMax = textRect.anchorMax;
            maskRect.pivot = textRect.pivot;
            maskRect.anchoredPosition = textRect.anchoredPosition;
            maskRect.sizeDelta = textRect.sizeDelta;
            maskRect.localRotation = textRect.localRotation;
            maskRect.localScale = textRect.localScale;
            mask.AddComponent<RectMask2D>();
            textRect.SetParent(mask.transform, false);
        }

        textRect.anchorMin = new Vector2(0f, 0f);
        textRect.anchorMax = new Vector2(0f, 1f);
        textRect.pivot = new Vector2(0f, 0.5f);
        textRect.anchoredPosition = Vector2.zero;
        textRect.localRotation = Quaternion.identity;
        textRect.localScale = Vector3.one;
        textRect.sizeDelta = new Vector2(260.0f, 0f);

        ConfigureOneLineText(text, minSize, maxSize, TextAlignmentOptions.MidlineLeft);
        text.overflowMode = TextOverflowModes.Overflow;
        text.raycastTarget = false;

        MarqueeText marquee = text.GetComponent<MarqueeText>() ?? text.gameObject.AddComponent<MarqueeText>();
        marquee.speed = 9f;
        marquee.pauseStart = 1.25f;
        marquee.pauseEnd = 0.8f;
        return marquee;
    }

    private static void ConfigureButtonText(Button btn, float minSize, float maxSize)
    {
        if (btn == null)
            return;

        TMP_Text label = btn.GetComponentInChildren<TMP_Text>();
        ConfigureOneLineText(label, minSize, maxSize, TextAlignmentOptions.Center);
        if (label != null)
            label.raycastTarget = false;
    }

    private static void ConfigureOneLineText(TMP_Text text, float minSize, float maxSize, TextAlignmentOptions alignment)
    {
        if (text == null)
            return;

        text.enableAutoSizing = true;
        text.fontSizeMin = minSize;
        text.fontSizeMax = maxSize;
        text.alignment = alignment;
        text.overflowMode = TextOverflowModes.Ellipsis;
        text.textWrappingMode = TextWrappingModes.NoWrap;
    }
}