using System;
using System.Collections.Generic;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

public static class SongDlcContentResolver
{
    private const string RuntimeResourcesFolder = "so/songDlcContents";
    private const string EditorSearchFolder = "Assets/Resources/so/songDlcContents";

    private static SongDlcContentSO[] cachedAllContents;
    private static readonly Dictionary<int, List<SongDlcContentSO>> CachedBySongId = new Dictionary<int, List<SongDlcContentSO>>();

    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
    private static void ResetStaticState()
    {
        cachedAllContents = null;
        CachedBySongId.Clear();
    }

    public static void InvalidateCache()
    {
        cachedAllContents = null;
        CachedBySongId.Clear();
    }

    public static SongDlcContentSO GetContent(SongData song)
    {
        if (song == null)
        {
            return null;
        }

        EnsureCacheBuilt();
        if (!CachedBySongId.TryGetValue(song.songID, out List<SongDlcContentSO> list) || list == null || list.Count == 0)
        {
            return null;
        }

        string preferredDlcKey = song.belongsTo_whichDLC ?? string.Empty;
        for (int i = 0; i < list.Count; i++)
        {
            SongDlcContentSO item = list[i];
            if (item == null)
            {
                continue;
            }

            if (IsMatchingDlc(item, preferredDlcKey))
            {
                return item;
            }
        }

        return list[0];
    }

    public static TextAsset GetChartFile(SongData song, int difficulty)
    {
        SongDlcContentSO content = GetContent(song);
        if (content == null || content.chartOverrides == null)
        {
            return null;
        }

        for (int i = 0; i < content.chartOverrides.Count; i++)
        {
            SongDlcChartOverrideEntry entry = content.chartOverrides[i];
            if (entry == null || entry.difficulty != difficulty || entry.chartFile == null)
            {
                continue;
            }

            return entry.chartFile;
        }

        return null;
    }

    public static AudioClip GetSettlementMusic(SongData song)
    {
        SongDlcContentSO content = GetContent(song);
        if (content != null && content.settlementMusic != null)
        {
            return content.settlementMusic;
        }

        dlcData owningDlc = GetOwningDlc(song);
        return owningDlc != null ? owningDlc.settlementMusic : null;
    }

    public static dlcData GetOwningDlc(SongData song)
    {
        if (song == null)
        {
            return null;
        }

        SongDlcContentSO content = GetContent(song);
        if (content != null && content.ownerDlc != null)
        {
            return content.ownerDlc;
        }

        dlcData[] allDlcs = RuntimeResourcesCache.LoadAllDlcs();
        string preferredDlcKey = song.belongsTo_whichDLC ?? string.Empty;
        dlcData fallback = null;

        for (int i = 0; i < allDlcs.Length; i++)
        {
            dlcData dlc = allDlcs[i];
            if (dlc == null)
            {
                continue;
            }

            if (dlc.songList != null && dlc.songList.Contains(song))
            {
                if (IsMatchingDlc(dlc, preferredDlcKey))
                {
                    return dlc;
                }

                fallback = fallback ?? dlc;
            }
        }

        return fallback;
    }

    public static SongDlcContentSO[] LoadAllSongDlcContents()
    {
        EnsureCacheBuilt();
        return cachedAllContents ?? Array.Empty<SongDlcContentSO>();
    }

    private static bool IsMatchingDlc(SongDlcContentSO content, string preferredDlcKey)
    {
        if (content == null)
        {
            return false;
        }

        if (!string.IsNullOrWhiteSpace(preferredDlcKey))
        {
            if (!string.IsNullOrWhiteSpace(content.sourceDlcId) &&
                string.Equals(content.sourceDlcId.Trim(), preferredDlcKey.Trim(), StringComparison.OrdinalIgnoreCase))
            {
                return true;
            }

            if (content.ownerDlc != null)
            {
                if (string.Equals(content.ownerDlc.dlcName ?? string.Empty, preferredDlcKey.Trim(), StringComparison.OrdinalIgnoreCase))
                {
                    return true;
                }

                if (string.Equals(content.ownerDlc.dlcID.ToString(), preferredDlcKey.Trim(), StringComparison.OrdinalIgnoreCase))
                {
                    return true;
                }
            }
        }

        return false;
    }

    private static bool IsMatchingDlc(dlcData dlc, string preferredDlcKey)
    {
        if (dlc == null || string.IsNullOrWhiteSpace(preferredDlcKey))
        {
            return false;
        }

        string safeKey = preferredDlcKey.Trim();
        return string.Equals(dlc.dlcName ?? string.Empty, safeKey, StringComparison.OrdinalIgnoreCase)
               || string.Equals(dlc.dlcID.ToString(), safeKey, StringComparison.OrdinalIgnoreCase);
    }

    private static void EnsureCacheBuilt()
    {
        if (cachedAllContents != null)
        {
            return;
        }

        cachedAllContents = LoadAllContentsInternal();
        CachedBySongId.Clear();

        for (int i = 0; i < cachedAllContents.Length; i++)
        {
            SongDlcContentSO content = cachedAllContents[i];
            if (content == null || content.songId <= 0)
            {
                continue;
            }

            if (!CachedBySongId.TryGetValue(content.songId, out List<SongDlcContentSO> list) || list == null)
            {
                list = new List<SongDlcContentSO>();
                CachedBySongId[content.songId] = list;
            }

            list.Add(content);
        }

        foreach (KeyValuePair<int, List<SongDlcContentSO>> pair in CachedBySongId)
        {
            pair.Value.Sort(CompareContent);
        }
    }

    private static int CompareContent(SongDlcContentSO left, SongDlcContentSO right)
    {
        if (ReferenceEquals(left, right))
        {
            return 0;
        }

        if (left == null)
        {
            return 1;
        }

        if (right == null)
        {
            return -1;
        }

        int ownerCompare = string.CompareOrdinal(left.sourceDlcId ?? string.Empty, right.sourceDlcId ?? string.Empty);
        if (ownerCompare != 0)
        {
            return ownerCompare;
        }

        return string.CompareOrdinal(left.GetResolvedContentId(), right.GetResolvedContentId());
    }

    private static SongDlcContentSO[] LoadAllContentsInternal()
    {
#if UNITY_EDITOR
        if (!Application.isPlaying)
        {
            string[] searchFolders = { EditorSearchFolder };
            string[] guids = AssetDatabase.FindAssets("t:SongDlcContentSO", searchFolders);
            if (guids != null && guids.Length > 0)
            {
                List<SongDlcContentSO> result = new List<SongDlcContentSO>(guids.Length);
                for (int i = 0; i < guids.Length; i++)
                {
                    string assetPath = AssetDatabase.GUIDToAssetPath(guids[i]);
                    SongDlcContentSO content = AssetDatabase.LoadAssetAtPath<SongDlcContentSO>(assetPath);
                    if (content != null)
                    {
                        result.Add(content);
                    }
                }

                return result.ToArray();
            }

            string[] fallbackGuids = AssetDatabase.FindAssets("t:SongDlcContentSO");
            List<SongDlcContentSO> fallback = new List<SongDlcContentSO>(fallbackGuids.Length);
            for (int i = 0; i < fallbackGuids.Length; i++)
            {
                string assetPath = AssetDatabase.GUIDToAssetPath(fallbackGuids[i]);
                SongDlcContentSO content = AssetDatabase.LoadAssetAtPath<SongDlcContentSO>(assetPath);
                if (content != null)
                {
                    fallback.Add(content);
                }
            }

            return fallback.ToArray();
        }
#endif

        return RuntimeResourcesCache.LoadAllSongDlcContents() ?? Array.Empty<SongDlcContentSO>();
    }
}