using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using Bansonic;
using GameServer.Client;
using UnityEngine;
using UnityEngine.UI;

#if !(UNITY_STANDALONE_WIN || UNITY_STANDALONE_LINUX || UNITY_STANDALONE_OSX || STEAMWORKS_WIN || STEAMWORKS_LIN_OSX)
#define FRIEND_DISABLE_STEAMWORKS
#endif

#if !FRIEND_DISABLE_STEAMWORKS
using Steamworks;
#endif

public enum FriendFilterType
{
    All,
    Online,
    Starred,
    Offline,
    GameFriends,
    SteamFriends
}

[Serializable]
public sealed class FriendCardViewData
{
    public string SteamId;
    public string DisplayName;
    public string AvatarUrl;
    public string StatusText;
    public bool IsOnline;
    public bool IsStarred;
    public bool IsGameFriend;
    public bool IsSteamFriend;
}

public class friendSystem : MonoBehaviour
{
    private const string LabelAllFriends = "全部好友";
    private const string LabelOnlineFriends = "在线好友";
    private const string LabelStarredFriends = "星标好友";
    private const string LabelOfflineFriends = "离线好友";
    private const string LabelGameFriends = "游戏好友";
    private const string LabelSteamFriends = "Steam好友";
    private const string StatusOnline = "在线";
    private const string StatusOffline = "离线";
    private const string StatusPlaying = "游戏中";
    private const string StatusInRoom = "房间中";
    private const string NoticeFriendDetailsNotReady = "好友详情面板尚未接入";
    private const string NoticePrivateChatNotReady = "私聊面板尚未接入";
    private const string DefaultStatusLoading = "正在拉取好友信息...";
    private const string DefaultStatusEmpty = "你当前没有好友";
    private const string DefaultStatusServiceUnavailable = "无法访问服务";

    public GameObject friendCardPrefab;
    public Transform friendsDisplayContent;

    [Header("filter")]
    public Dropdown friendsDisplayDropdown;

    [Header("text")]
    public Text defaultText;

    [Header("sync")]
    [SerializeField] private float steamFriendResyncIntervalSeconds = 8f;

    private readonly Dictionary<string, FriendCardViewData> _mergedFriends =
        new Dictionary<string, FriendCardViewData>(StringComparer.Ordinal);
    private readonly Dictionary<string, FriendCardViewData> _steamFriendCache =
        new Dictionary<string, FriendCardViewData>(StringComparer.Ordinal);
    private readonly Dictionary<string, GameObject> _spawnedCards =
        new Dictionary<string, GameObject>(StringComparer.Ordinal);
    private readonly List<(FriendFilterType filter, string label)> _filters =
        new List<(FriendFilterType filter, string label)>
        {
            (FriendFilterType.All, LabelAllFriends),
            (FriendFilterType.Online, LabelOnlineFriends),
            (FriendFilterType.Starred, LabelStarredFriends),
            (FriendFilterType.Offline, LabelOfflineFriends),
            (FriendFilterType.GameFriends, LabelGameFriends),
            (FriendFilterType.SteamFriends, LabelSteamFriends)
        };

    private bool _dropdownInitialized;
    private bool _isRefreshing;
    private bool _lastRefreshFailed;
    private Coroutine _resyncCoroutine;
    private static List<string> _startupSteamFriendIds = new List<string>();

    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
    private static void WarmSteamFriendIdsOnStartup()
    {
        _startupSteamFriendIds = ReadSteamFriendIdsOnly();
    }

    private void OnEnable()
    {
        ClearDisplayedFriends();
        SetDefaultText(DefaultStatusLoading);
        InitializeDropdown();

        if (ArenaRoomService.Instance != null)
        {
            ArenaRoomService.Instance.OnFriendsListChanged += HandleFriendsListChanged;
        }

        StartCoroutine(InitializeFriendsRoutine());
        if (_resyncCoroutine != null)
        {
            StopCoroutine(_resyncCoroutine);
        }
        _resyncCoroutine = StartCoroutine(SteamFriendResyncLoop());
    }

    private void OnDisable()
    {
        if (ArenaRoomService.Instance != null)
        {
            ArenaRoomService.Instance.OnFriendsListChanged -= HandleFriendsListChanged;
        }

        if (_resyncCoroutine != null)
        {
            StopCoroutine(_resyncCoroutine);
            _resyncCoroutine = null;
        }

        if (friendsDisplayDropdown != null)
        {
            friendsDisplayDropdown.onValueChanged.RemoveListener(HandleFilterChanged);
        }
    }

    private void ClearDisplayedFriends()
    {
        _spawnedCards.Clear();
        if (friendsDisplayContent == null)
        {
            return;
        }

        for (int index = friendsDisplayContent.childCount - 1; index >= 0; index--)
        {
            Transform child = friendsDisplayContent.GetChild(index);
            if (child != null)
            {
                Destroy(child.gameObject);
            }
        }
    }

    private IEnumerator InitializeFriendsRoutine()
    {
        if (_isRefreshing)
        {
            yield break;
        }

        _isRefreshing = true;
        _lastRefreshFailed = false;
        SetDefaultText(DefaultStatusLoading);
        RefreshSteamFriendCache();

        float waitDeadline = Time.realtimeSinceStartup + 3f;
        while (NetworkManager.Instance == null && Time.realtimeSinceStartup < waitDeadline)
        {
            yield return null;
        }

        NetworkManager network = NetworkManager.Instance;
        List<string> steamFriendIds = _steamFriendCache.Keys
            .Where(id => !string.IsNullOrWhiteSpace(id))
            .Distinct(StringComparer.Ordinal)
            .ToList();

        if (network != null)
        {
            var friendsTask = network.GetFriendsList(steamFriendIds);
            float timeoutAt = Time.realtimeSinceStartup + 20f;
            while (!friendsTask.IsCompleted && Time.realtimeSinceStartup < timeoutAt)
            {
                yield return null;
            }

            if (!friendsTask.IsCompleted)
            {
                _lastRefreshFailed = true;
                Debug.LogWarning("[friendSystem] GetFriendsList timed out.");
            }
            else if (friendsTask.Status == System.Threading.Tasks.TaskStatus.RanToCompletion
                && friendsTask.Result != null
                && friendsTask.Result.success)
            {
                ReplaceGameFriends(friendsTask.Result.friends);
            }
            else
            {
                _lastRefreshFailed = true;
                string error = friendsTask.IsFaulted ? friendsTask.Exception?.GetBaseException().Message : "friend list request failed";
                Debug.LogWarning($"[friendSystem] Initialize friends failed: {error}");
            }
        }
        else
        {
            _lastRefreshFailed = true;
            Debug.LogWarning("[friendSystem] NetworkManager is unavailable when initializing friends.");
        }

        Render();
        _isRefreshing = false;
    }

    private IEnumerator SteamFriendResyncLoop()
    {
        float interval = Mathf.Max(3f, steamFriendResyncIntervalSeconds);
        var wait = new WaitForSecondsRealtime(interval);
        while (isActiveAndEnabled)
        {
            yield return wait;
            if (_isRefreshing)
            {
                continue;
            }

            RefreshSteamFriendCache();
            if (!ShouldRetrySteamImport())
            {
                continue;
            }

            yield return InitializeFriendsRoutine();
        }
    }

    private void InitializeDropdown()
    {
        if (friendsDisplayDropdown == null)
        {
            return;
        }

        friendsDisplayDropdown.onValueChanged.RemoveListener(HandleFilterChanged);
        if (!_dropdownInitialized)
        {
            friendsDisplayDropdown.ClearOptions();
            friendsDisplayDropdown.AddOptions(_filters.Select(item => item.label).ToList());
            friendsDisplayDropdown.value = 0;
            _dropdownInitialized = true;
        }

        friendsDisplayDropdown.onValueChanged.AddListener(HandleFilterChanged);
        friendsDisplayDropdown.RefreshShownValue();
    }

    private void HandleFilterChanged(int _)
    {
        Render();
    }

    private void HandleFriendsListChanged(IReadOnlyList<SocialFriendEntry> friends)
    {
        _lastRefreshFailed = false;
        RefreshSteamFriendCache();
        ReplaceGameFriends(friends);
        Render();
    }

    private void RefreshSteamFriendCache()
    {
        CacheSteamFriends(ReadSteamFriends().Concat(BuildStartupSteamFriendCards()));
    }

    private bool ShouldRetrySteamImport()
    {
        if (_steamFriendCache.Count == 0)
        {
            return false;
        }

        foreach (KeyValuePair<string, FriendCardViewData> pair in _steamFriendCache)
        {
            FriendCardViewData steamFriend = pair.Value;
            if (steamFriend == null || string.IsNullOrWhiteSpace(steamFriend.SteamId))
            {
                continue;
            }

            if (_mergedFriends.ContainsKey(steamFriend.SteamId))
            {
                continue;
            }

            if (steamFriend.IsOnline || string.Equals(steamFriend.StatusText, StatusPlaying, StringComparison.Ordinal))
            {
                return true;
            }
        }

        return false;
    }

    private void CacheSteamFriends(IEnumerable<FriendCardViewData> steamFriends)
    {
        _steamFriendCache.Clear();
        if (steamFriends == null)
        {
            return;
        }

        foreach (FriendCardViewData steamFriend in steamFriends)
        {
            if (steamFriend == null || string.IsNullOrWhiteSpace(steamFriend.SteamId))
            {
                continue;
            }

            steamFriend.IsStarred = LoadStarredState(steamFriend.SteamId);
            _steamFriendCache[steamFriend.SteamId] = steamFriend;
        }
    }

    private void ReplaceGameFriends(IEnumerable<SocialFriendEntry> gameFriends)
    {
        _mergedFriends.Clear();
        if (gameFriends == null)
        {
            return;
        }

        foreach (SocialFriendEntry gameFriend in gameFriends)
        {
            if (gameFriend == null || string.IsNullOrWhiteSpace(gameFriend.friend_steam_id))
            {
                continue;
            }

            string steamId = gameFriend.friend_steam_id.Trim();
            _steamFriendCache.TryGetValue(steamId, out FriendCardViewData steamFriend);
            bool steamSaysPlaying = steamFriend != null && string.Equals(steamFriend.StatusText, StatusPlaying, StringComparison.Ordinal);
            bool mergedOnline = gameFriend.online || (steamFriend != null && steamFriend.IsOnline) || steamSaysPlaying;
            string mergedStatus = MapServerPresenceToStatusText(gameFriend.status, steamFriend, mergedOnline);

            FriendCardViewData merged = new FriendCardViewData
            {
                SteamId = steamId,
                DisplayName = ResolvePreferredDisplayName(
                    steamFriend != null ? steamFriend.DisplayName : string.Empty,
                    NetworkManager.ResolveDisplayName(gameFriend.friend_name, steamId, false),
                    steamId),
                AvatarUrl = ResolvePreferredAvatarUrl(
                    steamFriend != null ? steamFriend.AvatarUrl : string.Empty,
                    NetworkManager.ResolveAvatarUrl(gameFriend.friend_avatar, steamId),
                    steamId),
                StatusText = mergedStatus,
                IsOnline = mergedOnline,
                IsStarred = LoadStarredState(steamId),
                IsGameFriend = true,
                IsSteamFriend = steamFriend != null
            };

            _mergedFriends[steamId] = merged;
        }
    }

    private async System.Threading.Tasks.Task HydrateRegisteredSteamFriendsAsync(NetworkManager network)
    {
        if (network == null || _steamFriendCache.Count == 0)
        {
            return;
        }

        foreach (KeyValuePair<string, FriendCardViewData> pair in _steamFriendCache)
        {
            string steamId = pair.Key;
            FriendCardViewData steamFriend = pair.Value;
            if (string.IsNullOrWhiteSpace(steamId) || _mergedFriends.ContainsKey(steamId))
            {
                continue;
            }

            ProfileData profile;
            try
            {
                profile = await network.GetProfile(steamId);
            }
            catch
            {
                continue;
            }

            if (profile == null || string.IsNullOrWhiteSpace(profile.steam_id))
            {
                continue;
            }

            bool steamSaysPlaying = steamFriend != null && string.Equals(steamFriend.StatusText, StatusPlaying, StringComparison.Ordinal);
            bool mergedOnline = steamFriend != null && steamFriend.IsOnline;
            string mergedStatus = steamSaysPlaying ? StatusPlaying : (mergedOnline ? StatusOnline : StatusOffline);

            _mergedFriends[steamId] = new FriendCardViewData
            {
                SteamId = steamId,
                DisplayName = ResolvePreferredDisplayName(
                    steamFriend != null ? steamFriend.DisplayName : string.Empty,
                    NetworkManager.ResolveDisplayName(profile.display_name, steamId, false),
                    steamId),
                AvatarUrl = ResolvePreferredAvatarUrl(
                    steamFriend != null ? steamFriend.AvatarUrl : string.Empty,
                    NetworkManager.ResolveAvatarUrl(profile.avatar_url, steamId),
                    steamId),
                StatusText = mergedStatus,
                IsOnline = mergedOnline,
                IsStarred = LoadStarredState(steamId),
                IsGameFriend = true,
                IsSteamFriend = true
            };
        }
    }

    private void Render()
    {
        if (friendsDisplayContent == null || friendCardPrefab == null)
        {
            SetDefaultText(DefaultStatusServiceUnavailable);
            return;
        }

        List<FriendCardViewData> target = ApplyFilter(_mergedFriends.Values)
            .OrderBy(friend => GetSortBucket(friend))
            .ThenBy(friend => friend.DisplayName ?? string.Empty, StringComparer.OrdinalIgnoreCase)
            .ThenBy(friend => friend.SteamId ?? string.Empty, StringComparer.OrdinalIgnoreCase)
            .ToList();

        HashSet<string> targetIds = new HashSet<string>(target.Select(friend => friend.SteamId), StringComparer.Ordinal);
        foreach (KeyValuePair<string, GameObject> pair in _spawnedCards.ToList())
        {
            if (targetIds.Contains(pair.Key))
            {
                continue;
            }

            Destroy(pair.Value);
            _spawnedCards.Remove(pair.Key);
        }

        for (int index = 0; index < target.Count; index++)
        {
            FriendCardViewData friend = target[index];
            if (!_spawnedCards.TryGetValue(friend.SteamId, out GameObject cardObject) || cardObject == null)
            {
                cardObject = Instantiate(friendCardPrefab, friendsDisplayContent);
                _spawnedCards[friend.SteamId] = cardObject;
            }

            cardObject.transform.SetSiblingIndex(index);
            friendCardPrefab card = cardObject.GetComponent<friendCardPrefab>();
            if (card != null)
            {
                card.Bind(friend, HandleStarChanged, HandleOpenDetails, HandleOpenPrivateConversation);
            }
        }

        UpdateDefaultTextState(target.Count);
    }

    private void UpdateDefaultTextState(int visibleCount)
    {
        if (_lastRefreshFailed)
        {
            SetDefaultText(DefaultStatusServiceUnavailable);
            return;
        }

        if (visibleCount > 0)
        {
            SetDefaultText(string.Empty);
            return;
        }

        SetDefaultText(DefaultStatusEmpty);
    }

    private void SetDefaultText(string message)
    {
        if (defaultText == null)
        {
            return;
        }

        defaultText.text = message ?? string.Empty;
    }

    private IEnumerable<FriendCardViewData> ApplyFilter(IEnumerable<FriendCardViewData> source)
    {
        FriendFilterType filter = GetSelectedFilter();
        switch (filter)
        {
            case FriendFilterType.All:
                return source;
            case FriendFilterType.Online:
                return source.Where(friend => friend.IsOnline);
            case FriendFilterType.Starred:
                return source.Where(friend => friend.IsStarred);
            case FriendFilterType.Offline:
                return source.Where(friend => !friend.IsOnline);
            case FriendFilterType.GameFriends:
                return source.Where(friend => friend.IsGameFriend);
            case FriendFilterType.SteamFriends:
                return source.Where(friend => friend.IsSteamFriend);
            default:
                return source;
        }
    }

    private FriendFilterType GetSelectedFilter()
    {
        if (friendsDisplayDropdown == null || friendsDisplayDropdown.value < 0 || friendsDisplayDropdown.value >= _filters.Count)
        {
            return FriendFilterType.All;
        }

        return _filters[friendsDisplayDropdown.value].filter;
    }

    private void HandleStarChanged(string steamId, bool isOn)
    {
        if (string.IsNullOrWhiteSpace(steamId))
        {
            return;
        }

        PlayerPrefs.SetInt(BuildStarKey(steamId), isOn ? 1 : 0);
        PlayerPrefs.Save();

        if (_mergedFriends.TryGetValue(steamId, out FriendCardViewData friend) && friend != null)
        {
            friend.IsStarred = isOn;
        }

        if (_steamFriendCache.TryGetValue(steamId, out FriendCardViewData steamFriend) && steamFriend != null)
        {
            steamFriend.IsStarred = isOn;
        }

        Render();
    }

    private void HandleOpenDetails(string steamId)
    {
        if (string.IsNullOrWhiteSpace(steamId))
        {
            return;
        }

        gNotice.warning.display(NoticeFriendDetailsNotReady);
    }

    private void HandleOpenPrivateConversation(string steamId)
    {
        if (string.IsNullOrWhiteSpace(steamId))
        {
            return;
        }

        globalChatSystem.OpenPrivateConversation(steamId);
    }

    private static int GetSortBucket(FriendCardViewData friend)
    {
        if (friend == null)
        {
            return int.MaxValue;
        }

        if (friend.IsStarred && friend.IsOnline)
        {
            return 0;
        }

        if (friend.IsStarred && !friend.IsOnline)
        {
            return 1;
        }

        if (!friend.IsStarred && friend.IsOnline)
        {
            return 2;
        }

        return 3;
    }

    private static string ResolvePreferredDisplayName(string currentDisplayName, string newDisplayName, string steamId)
    {
        if (NetworkManager.IsUsableDisplayName(newDisplayName, steamId))
        {
            return newDisplayName;
        }

        if (NetworkManager.IsUsableDisplayName(currentDisplayName, steamId))
        {
            return currentDisplayName;
        }

        return string.Empty;
    }

    private static string ResolvePreferredAvatarUrl(string currentAvatarUrl, string newAvatarUrl, string steamId)
    {
        if (NetworkManager.IsUsableAvatarUrl(newAvatarUrl))
        {
            return newAvatarUrl;
        }

        if (NetworkManager.IsUsableAvatarUrl(currentAvatarUrl))
        {
            return currentAvatarUrl;
        }

        return NetworkManager.ResolveAvatarUrl(string.Empty, steamId);
    }

    private static string BuildStarKey(string steamId)
    {
        return $"friend_star_{steamId}";
    }

    private static bool LoadStarredState(string steamId)
    {
        if (string.IsNullOrWhiteSpace(steamId))
        {
            return false;
        }

        return PlayerPrefs.GetInt(BuildStarKey(steamId), 0) == 1;
    }

    private static List<FriendCardViewData> ReadSteamFriends()
    {
        var result = new List<FriendCardViewData>();
#if FRIEND_DISABLE_STEAMWORKS
        return result;
#else
        if (!SteamManager.Initialized)
        {
            return result;
        }

        int count = SteamFriends.GetFriendCount(EFriendFlags.k_EFriendFlagImmediate);
        for (int index = 0; index < count; index++)
        {
            CSteamID friendSteamId = SteamFriends.GetFriendByIndex(index, EFriendFlags.k_EFriendFlagImmediate);
            string steamId = friendSteamId.m_SteamID.ToString();
            SteamFriends.RequestUserInformation(friendSteamId, false);

            string displayName = SteamFriends.GetFriendPersonaName(friendSteamId);
            EPersonaState personaState = SteamFriends.GetFriendPersonaState(friendSteamId);
            FriendGameInfo_t gameInfo;
            bool isPlaying = SteamFriends.GetFriendGamePlayed(friendSteamId, out gameInfo);
            bool isOnline = personaState != EPersonaState.k_EPersonaStateOffline;
            string statusText = isPlaying ? StatusPlaying : (isOnline ? StatusOnline : StatusOffline);

            result.Add(
                new FriendCardViewData
                {
                    SteamId = steamId,
                    DisplayName = NetworkManager.ResolveDisplayName(displayName, steamId, false),
                    AvatarUrl = NetworkManager.ResolveAvatarUrl(string.Empty, steamId),
                    StatusText = statusText,
                    IsOnline = isOnline,
                    IsSteamFriend = true,
                    IsGameFriend = false,
                    IsStarred = LoadStarredState(steamId)
                }
            );
        }

        return result;
#endif
    }

    private static IEnumerable<FriendCardViewData> BuildStartupSteamFriendCards()
    {
        if (_startupSteamFriendIds == null || _startupSteamFriendIds.Count == 0)
        {
            yield break;
        }

        foreach (string steamId in _startupSteamFriendIds)
        {
            if (string.IsNullOrWhiteSpace(steamId))
            {
                continue;
            }

            yield return new FriendCardViewData
            {
                SteamId = steamId,
                DisplayName = NetworkManager.ResolveDisplayName(string.Empty, steamId, false),
                AvatarUrl = NetworkManager.ResolveAvatarUrl(string.Empty, steamId),
                StatusText = string.Empty,
                IsOnline = false,
                IsSteamFriend = true,
                IsGameFriend = false,
                IsStarred = LoadStarredState(steamId)
            };
        }
    }

    private static List<string> ReadSteamFriendIdsOnly()
    {
        var result = new List<string>();
#if FRIEND_DISABLE_STEAMWORKS
        return result;
#else
        if (!SteamManager.Initialized)
        {
            return result;
        }

        int count = SteamFriends.GetFriendCount(EFriendFlags.k_EFriendFlagImmediate);
        for (int index = 0; index < count; index++)
        {
            CSteamID friendSteamId = SteamFriends.GetFriendByIndex(index, EFriendFlags.k_EFriendFlagImmediate);
            string steamId = friendSteamId.m_SteamID.ToString();
            if (!string.IsNullOrWhiteSpace(steamId))
            {
                result.Add(steamId);
            }
        }

        return result.Distinct(StringComparer.Ordinal).ToList();
#endif
    }

    private static string MapServerPresenceToStatusText(string status, FriendCardViewData steamFriend, bool mergedOnline)
    {
        if (string.Equals(status, "IN_GAME", StringComparison.OrdinalIgnoreCase))
        {
            return StatusPlaying;
        }

        if (string.Equals(status, "IN_ROOM", StringComparison.OrdinalIgnoreCase))
        {
            return StatusInRoom;
        }

        if (string.Equals(status, "ONLINE", StringComparison.OrdinalIgnoreCase))
        {
            return StatusOnline;
        }

        if (string.Equals(status, "OFFLINE", StringComparison.OrdinalIgnoreCase))
        {
            return StatusOffline;
        }

        if (steamFriend != null && string.Equals(steamFriend.StatusText, StatusPlaying, StringComparison.Ordinal))
        {
            return StatusPlaying;
        }

        return mergedOnline ? StatusOnline : StatusOffline;
    }
}