using System.Text.Encodings.Web;
using System.Text.Json;
using CounterStrikeSharp.API;
using CounterStrikeSharp.API.Core;
using CounterStrikeSharp.API.Core.Attributes.Registration;
using CounterStrikeSharp.API.Core.Capabilities;
using CounterStrikeSharp.API.Modules.Admin;
using CounterStrikeSharp.API.Modules.Commands;
using CounterStrikeSharp.API.Modules.Entities;
using CounterStrikeSharp.API.Modules.Timers;
using CounterStrikeSharp.API.Modules.Utils;
using CS2_SimpleAdminApi;
using Microsoft.Extensions.Logging;

namespace Whisper;

// Private messages between players: /pm <target> <message>, /r to reply, and /block, /blocklist,
// /unblock. Lines use CS2-Tags' rank prefixes and colours from tags.json. While History is on, every
// message is kept in CS2-SimpleAdmin's database (wh_messages): private ones, all and team chat, @
// staff chat and SimpleAdmin's say commands. Blocks are in wh_blocks.
//
// Chat is seen by a catch-all command listener added in Load. CSS runs catch-alls before any
// per-command listener, in the order they were added, and stops at the first that returns Stop.
// CS2-SimpleAdmin adds its own (which stops gagged players' chat and handles @) in
// OnAllPluginsLoaded, after every plugin's Load, so this one always sees a line first. It only
// looks, never blocks.
//
// Chat commands are caught in a say listener rather than left to CSS's chat triggers: for "!pm" the
// game prints the whole line, message and all, to everyone before CSS runs the command. Stopping
// "say" there means nothing is printed and CSS never dispatches it, so it runs once.
//
// Threads: every field below is only touched on the game thread. Database reads run in Task.Run and
// hand back with Server.NextFrame; writes go through the Writer.
public class Whisper : BasePlugin, IPluginConfig<WhisperConfig>
{
    public override string ModuleName => "Whisper";
    public override string ModuleVersion => "0.2.0";
    public override string ModuleAuthor => "astra";
    public override string ModuleDescription => "Private messages between players";

    private static readonly PluginCapability<ICS2_SimpleAdminApi> SimpleAdminCapability = new("simpleadmin:api");

    // Chat words handled here, after a chat trigger ("!pm", "/pm").
    private static readonly HashSet<string> ChatCommands = new(StringComparer.OrdinalIgnoreCase)
        { "pm", "w", "r", "block", "blocklist", "unblock" };

    // SimpleAdmin's commands that send a message, logged under their own name as the channel.
    private static readonly HashSet<string> StaffCommands = new(StringComparer.OrdinalIgnoreCase)
        { "css_say", "css_asay", "css_psay", "css_csay", "css_hsay", "css_cssay" };

    // Targets that mean more than one player. A PM goes to one.
    private static readonly HashSet<string> GroupTargets = new(StringComparer.OrdinalIgnoreCase)
        { "@all", "@t", "@ct", "@spec", "@alive", "@dead", "@bot", "@bots", "@human", "@humans", "@!me" };

    public WhisperConfig Config { get; set; } = new();

    private ICS2_SimpleAdminApi? _simpleAdmin;
    private Database? _db;
    private Writer? _writer;
    private Tags? _tags;

    // SteamID64 -> their blocks, oldest first; null while still loading from the database.
    private readonly Dictionary<ulong, List<Database.Block>?> _blocks = [];
    // SteamID64 -> who last sent them a PM, for /r.
    private readonly Dictionary<ulong, ulong> _lastFrom = [];
    // SteamID64 -> when they may send again (UTC).
    private readonly Dictionary<ulong, DateTime> _nextSend = [];

    public void OnConfigParsed(WhisperConfig config)
    {
        config.CooldownSeconds = Math.Max(0, config.CooldownSeconds);
        config.MaxMessageLength = Math.Clamp(config.MaxMessageLength, 1, 512);
        config.MaxBlocks = Math.Max(1, config.MaxBlocks);
        config.SpoolMaxEntries = Math.Max(0, config.SpoolMaxEntries);
        Config = config;
    }

    public override void Load(bool hotReload)
    {
        _tags = new Tags(Path.Combine(Server.GameDirectory, "csgo", "addons", "counterstrikesharp", Config.TagsFile),
            message => Logger.LogWarning("{Message}", message));

        // In Load, not OnAllPluginsLoaded: see the top of this file.
        AddCommandListener(null, OnAnyCommand, HookMode.Pre);
        AddCommandListener("say", OnSay, HookMode.Pre);
        AddCommandListener("say_team", OnSay, HookMode.Pre);
        RegisterEventHandler<EventPlayerConnectFull>(OnPlayerConnectFull);
        RegisterListener<Listeners.OnClientDisconnect>(OnClientDisconnect);

        // Block lists that couldn't be read (the database was down) are tried again.
        AddTimer(30.0f, () =>
        {
            foreach (var (steamId, blocks) in _blocks.ToList())
                if (blocks == null)
                    LoadBlocks(steamId);
        }, TimerFlags.REPEAT);
    }

    public override void OnAllPluginsLoaded(bool hotReload)
    {
        try
        {
            _simpleAdmin = SimpleAdminCapability.Get();
        }
        catch (KeyNotFoundException)
        {
        }

        var connectionString = _simpleAdmin?.GetConnectionString();
        if (string.IsNullOrEmpty(connectionString))
            Logger.LogError("No CS2-SimpleAdmin MySQL database: messages work, but blocks last only until the map changes");
        else
        {
            _db = new Database(connectionString);
            _writer = new Writer(_db, Path.Combine(ModuleDirectory, "spool.jsonl"), Config.SpoolMaxEntries, Logger);
            _writer.Start();
        }

        foreach (var player in Humans())
            LoadBlocks(player.SteamID);
    }

    public override void Unload(bool hotReload)
    {
        _writer?.Drain(TimeSpan.FromSeconds(5));
    }

    // --- Players --------------------------------------------------------------------

    private static List<CCSPlayerController> Humans() =>
        Utilities.GetPlayers().Where(p => p is { IsValid: true, IsBot: false, IsHLTV: false } &&
                                          p.Connected == PlayerConnectedState.Connected && p.SteamID != 0).ToList();

    private bool IsStaff(CCSPlayerController player) =>
        AdminManager.PlayerHasPermissions(player, Config.StaffPermission);

    private bool IsHidden(CCSPlayerController player)
    {
        try
        {
            return _simpleAdmin?.IsAdminSilent(player) ?? false;
        }
        catch (Exception)
        {
            return false;
        }
    }

    // Admins hidden with css_hide can't be found, except by staff and themselves.
    private bool CanSee(CCSPlayerController sender, CCSPlayerController player) =>
        player.SteamID == sender.SteamID || !IsHidden(player) || IsStaff(sender);

    private static PlayerState StateOf(CCSPlayerController player)
    {
        var team = (int)player.TeamNum;
        var alive = team >= (int)CsTeam.Terrorist && player.PlayerPawn.Value is { IsValid: true } pawn &&
                    pawn.LifeState == (byte)LifeState_t.LIFE_ALIVE;
        return new PlayerState(player.SteamID, player.PlayerName, team, alive);
    }

    private HookResult OnPlayerConnectFull(EventPlayerConnectFull @event, GameEventInfo info)
    {
        if (@event.Userid is { IsValid: true, IsBot: false, IsHLTV: false } player && player.SteamID != 0)
            LoadBlocks(player.SteamID);
        return HookResult.Continue;
    }

    private void OnClientDisconnect(int slot)
    {
        var player = Utilities.GetPlayerFromSlot(slot);
        if (player is not { IsValid: true } || player.SteamID == 0)
            return;
        var steamId = player.SteamID;
        // Next frame, once they're out of the player list.
        Server.NextFrame(() =>
        {
            if (Humans().Any(p => p.SteamID == steamId))
                return;
            _blocks.Remove(steamId);
            _lastFrom.Remove(steamId);
            _nextSend.Remove(steamId);
        });
    }

    private void LoadBlocks(ulong steamId)
    {
        if (_db == null)
        {
            _blocks.TryAdd(steamId, []);
            return;
        }
        if (_blocks.TryGetValue(steamId, out var known) && known != null)
            return;
        _blocks[steamId] = null;
        var db = _db;
        Task.Run(async () =>
        {
            try
            {
                var blocks = await db.BlocksAsync(steamId);
                Server.NextFrame(() =>
                {
                    if (_blocks.TryGetValue(steamId, out var current) && current == null)
                        _blocks[steamId] = blocks;
                });
            }
            catch (Exception ex)
            {
                Logger.LogWarning("Couldn't read {SteamId}'s blocks, trying again shortly: {Error}", steamId, ex.Message);
            }
        });
    }

    // --- Chat -----------------------------------------------------------------------

    // Logs chat and staff messages as they're sent. Never blocks anything.
    private HookResult OnAnyCommand(CCSPlayerController? player, CommandInfo info)
    {
        if (!Config.History || _writer == null)
            return HookResult.Continue;
        var command = info.GetArg(0).ToLowerInvariant();

        if (StaffCommands.Contains(command))
        {
            // Typed in console, RCON (the web panel too), or "!asay" in chat, which CSS runs as css_asay.
            var sender = player is { IsValid: true, IsBot: false } ? StateOf(player) : player == null ? PlayerState.Console : null;
            if (sender == null)
                return HookResult.Continue;
            var rest = info.ArgString;
            var target = command == "css_psay" ? NextToken(ref rest) : null;
            var message = rest.Trim();
            if (message.Length > 0)
                Log(command, sender, null, target, message, Result.Sent);
            return HookResult.Continue;
        }

        if (command is not ("say" or "say_team") || player is not { IsValid: true, IsBot: false })
            return HookResult.Continue;
        var text = info.GetArg(1);
        if (text.Length == 0)
            return HookResult.Continue;
        var team = command == "say_team";
        var channel = team ? ChatChannel.Team : ChatChannel.All;

        var trigger = ChatTrigger(text);
        if (trigger != null)
        {
            var rest = text[trigger.Length..];
            var word = NextToken(ref rest).ToLowerInvariant();
            // Logged on their own: PMs where they're sent, "!asay" and the like as the command.
            if (!ChatCommands.Contains(word) && !StaffCommands.Contains("css_" + word))
                Log(channel, StateOf(player), null, null, text, Result.Command);
            return HookResult.Continue;
        }

        if (text.StartsWith('@'))
        {
            var chatStaff = AdminManager.PlayerHasPermissions(player, "@css/chat");
            // SimpleAdmin runs this as css_say, which is logged then.
            if (!team && chatStaff)
                return HookResult.Continue;
            // @ team chat goes to staff, and gets through a gag.
            if (team)
            {
                Log(chatStaff ? ChatChannel.Staff : ChatChannel.ToStaff, StateOf(player), null, null, text[1..].Trim(), Result.Sent);
                return HookResult.Continue;
            }
        }

        Log(channel, StateOf(player), null, null, text, IsGagged(player, out _) ? Result.Gagged : Result.Sent);
        return HookResult.Continue;
    }

    private static string? ChatTrigger(string text) =>
        CoreConfig.PublicChatTrigger.Concat(CoreConfig.SilentChatTrigger).FirstOrDefault(t => t.Length > 0 && text.StartsWith(t));

    private HookResult OnSay(CCSPlayerController? player, CommandInfo info)
    {
        if (player is not { IsValid: true, IsBot: false })
            return HookResult.Continue;
        var text = info.GetArg(1);
        var trigger = ChatTrigger(text);
        if (trigger == null)
            return HookResult.Continue;

        var rest = text[trigger.Length..];
        var word = NextToken(ref rest);
        if (!ChatCommands.Contains(word))
            return HookResult.Continue;

        Run(player, word.ToLowerInvariant(), rest.Trim(), reply => player.PrintToChat(reply));
        return HookResult.Stop;
    }

    [ConsoleCommand("css_pm", "Sends a private message")]
    [ConsoleCommand("css_w", "Sends a private message")]
    [CommandHelper(usage: "<name|#userid|@randomt|...> <message>", whoCanExecute: CommandUsage.CLIENT_ONLY)]
    public void OnPmCommand(CCSPlayerController? player, CommandInfo command) => RunConsole(player, command, "pm");

    [ConsoleCommand("css_r", "Replies to the last private message")]
    [CommandHelper(usage: "<message>", whoCanExecute: CommandUsage.CLIENT_ONLY)]
    public void OnReplyCommand(CCSPlayerController? player, CommandInfo command) => RunConsole(player, command, "r");

    [ConsoleCommand("css_block", "Stops a player sending you private messages")]
    [CommandHelper(usage: "<#userid|steamid64>", whoCanExecute: CommandUsage.CLIENT_ONLY)]
    public void OnBlockCommand(CCSPlayerController? player, CommandInfo command) => RunConsole(player, command, "block");

    [ConsoleCommand("css_blocklist", "Lists who you've blocked")]
    [CommandHelper(whoCanExecute: CommandUsage.CLIENT_ONLY)]
    public void OnBlockListCommand(CCSPlayerController? player, CommandInfo command) => RunConsole(player, command, "blocklist");

    [ConsoleCommand("css_unblock", "Unblocks a player, by their number in /blocklist")]
    [CommandHelper(usage: "<number from /blocklist>", whoCanExecute: CommandUsage.CLIENT_ONLY)]
    public void OnUnblockCommand(CCSPlayerController? player, CommandInfo command) => RunConsole(player, command, "unblock");

    private void RunConsole(CCSPlayerController? player, CommandInfo command, string word)
    {
        if (player is not { IsValid: true, IsBot: false })
            return;
        Run(player, word, command.ArgString.Trim(), reply => command.ReplyToCommand(reply));
    }

    private void Run(CCSPlayerController player, string word, string args, Action<string> reply)
    {
        switch (word)
        {
            case "pm":
            case "w":
                SendCommand(player, args, reply);
                break;
            case "r":
                ReplyCommand(player, args, reply);
                break;
            case "block":
                Block(player, args, reply);
                break;
            case "blocklist":
                BlockList(player, reply);
                break;
            case "unblock":
                Unblock(player, args, reply);
                break;
        }
    }

    // The next word, or a "quoted name with spaces", taken off the front of text.
    private static string NextToken(ref string text)
    {
        text = text.TrimStart();
        if (text.Length == 0)
            return "";
        if (text[0] == '"')
        {
            var close = text.IndexOf('"', 1);
            var quoted = close < 0 ? text[1..] : text[1..close];
            text = close < 0 ? "" : text[(close + 1)..];
            return quoted;
        }
        var end = text.IndexOfAny([' ', '\t']);
        var token = end < 0 ? text : text[..end];
        text = end < 0 ? "" : text[end..];
        return token;
    }

    // --- Sending --------------------------------------------------------------------

    private static string Notice(string text) => $" {ChatColors.Default}{text}";

    private void SendCommand(CCSPlayerController sender, string args, Action<string> reply)
    {
        var rest = args;
        var target = NextToken(ref rest);
        var message = rest.Trim();
        if (target.Length == 0 || message.Length == 0)
        {
            reply(Notice("Usage: /pm <name|#userid|@aim|@randomt|@randomct|@random|@me> <message>"));
            return;
        }

        var (recipient, result, problem) = Resolve(sender, target);
        if (recipient == null)
        {
            Log(sender, null, target, message, result);
            reply(Notice(problem));
            return;
        }
        Deliver(sender, recipient, target, message, reply);
    }

    private void ReplyCommand(CCSPlayerController sender, string args, Action<string> reply)
    {
        var message = args.Trim();
        if (message.Length == 0)
        {
            reply(Notice("Usage: /r <message>"));
            return;
        }
        if (!_lastFrom.TryGetValue(sender.SteamID, out var from))
        {
            reply(Notice("No one has sent you a private message yet."));
            return;
        }
        var recipient = Humans().FirstOrDefault(p => p.SteamID == from && CanSee(sender, p));
        if (recipient == null)
        {
            Log(sender, null, "/r", message, Result.NoTarget);
            reply(Notice("They're not on the server any more."));
            return;
        }
        Deliver(sender, recipient, "/r", message, reply);
    }

    private void Deliver(CCSPlayerController sender, CCSPlayerController recipient, string target, string message, Action<string> reply)
    {
        if (IsGagged(sender, out var permanent))
        {
            Log(sender, recipient, target, message, Result.Gagged);
            reply(Notice(permanent
                ? "You can't send private messages: you're gagged permanently."
                : "You can't send private messages while you're gagged."));
            return;
        }
        var now = DateTime.UtcNow;
        if (_nextSend.TryGetValue(sender.SteamID, out var next) && now < next)
        {
            Log(sender, recipient, target, message, Result.Cooldown);
            reply(Notice("You're sending messages too quickly."));
            return;
        }
        if (message.Length > Config.MaxMessageLength)
        {
            Log(sender, recipient, target, message, Result.TooLong);
            reply(Notice($"That message is too long (at most {Config.MaxMessageLength} characters)."));
            return;
        }
        var self = recipient.SteamID == sender.SteamID;
        if (!self && !IsStaff(sender) && _blocks.TryGetValue(recipient.SteamID, out var blocks) &&
            blocks?.Any(b => b.SteamId == sender.SteamID) == true)
        {
            Log(sender, recipient, target, message, Result.Blocked);
            reply(Notice($"{recipient.PlayerName} isn't accepting your messages."));
            return;
        }

        _nextSend[sender.SteamID] = now.AddSeconds(Config.CooldownSeconds);
        var (from, color) = Speaker(sender);
        recipient.PrintToChat($" {Tags.Colors(Config.Open)}{from} {Tags.Colors(Config.Arrow)} {Tags.Colors(Config.Me)}{Tags.Colors(Config.Close)} {color}{message}");
        if (!self)
        {
            sender.PrintToChat($" {Tags.Colors(Config.Open)}{from} {Tags.Colors(Config.Arrow)} {Nick(recipient)}{Tags.Colors(Config.Close)} {color}{message}");
            _lastFrom[recipient.SteamID] = sender.SteamID;
        }
        Log(sender, recipient, target, message, Result.Sent);
    }

    // The sender as the line shows them, "[M] Kalus" in tags.json's colours, and their message colour.
    private (string From, string MessageColor) Speaker(CCSPlayerController player)
    {
        var tag = _tags?.Find(player);
        var team = (int)player.TeamNum;
        var prefix = tag is { Prefix: not "" } ? Tags.Colors(tag.Prefix, team).TrimEnd() + " " : "";
        var color = tag is { MessageColor: not "" } ? Tags.Colors(tag.MessageColor, team) : ChatColors.Default.ToString();
        return ($"{prefix}{Nick(player, tag)}", color);
    }

    // A name in its nick_color from tags.json, or the team colour when that's empty.
    private string Nick(CCSPlayerController player, Tags.Tag? tag = null)
    {
        tag ??= _tags?.Find(player);
        var team = (int)player.TeamNum;
        var color = tag is { NickColor: not "" } ? Tags.Colors(tag.NickColor, team) : Tags.TeamColor(team);
        return $"{ChatColors.Default}{color}{player.PlayerName}";
    }

    private bool IsGagged(CCSPlayerController player, out bool permanent)
    {
        permanent = false;
        if (_simpleAdmin == null)
            return false;
        try
        {
            var status = _simpleAdmin.GetPlayerMuteStatus(player);
            var blocks = new[] { PenaltyType.Gag, PenaltyType.Silence }
                .SelectMany(t => status.TryGetValue(t, out var list) ? list : []).ToList();
            permanent = blocks.Any(b => b.Duration == 0);
            return blocks.Count > 0;
        }
        catch (Exception)
        {
            return false;
        }
    }

    // --- Targets --------------------------------------------------------------------

    // One player from a name, #userid (as css_players shows it), SteamID64 or STEAM_ ID, @me, @aim,
    // @random, @randomt or @randomct. Never a bot, and never a hidden admin unless staff are asking.
    private (CCSPlayerController? Player, string Result, string Problem) Resolve(CCSPlayerController sender, string target)
    {
        var humans = Humans().Where(p => CanSee(sender, p)).ToList();
        if (GroupTargets.Contains(target))
            return (null, Result.GroupTarget, "Private messages go to one player at a time.");

        if (target.StartsWith('@'))
        {
            switch (target.ToLowerInvariant())
            {
                case "@me":
                    return (sender, Result.Sent, "");
                case "@aim":
                {
                    var rules = Utilities.FindAllEntitiesByDesignerName<CCSGameRulesProxy>("cs_gamerules").FirstOrDefault()?.GameRules;
                    var aimed = rules?.GetClientAimTarget(sender);
                    var found = aimed == null ? null : humans.FirstOrDefault(p => p.Slot == aimed.Slot);
                    return found != null ? (found, Result.Sent, "") : (null, Result.NoTarget, "You're not looking at a player.");
                }
                case "@random":
                case "@randomt":
                case "@randomct":
                {
                    var team = target.ToLowerInvariant() switch
                    {
                        "@randomt" => (int)CsTeam.Terrorist,
                        "@randomct" => (int)CsTeam.CounterTerrorist,
                        _ => -1,
                    };
                    // Never a hidden admin, even for staff: a random pick shouldn't land on one.
                    var pool = humans.Where(p => p.SteamID != sender.SteamID && !IsHidden(p) && (team < 0 || p.TeamNum == team)).ToList();
                    return pool.Count == 0
                        ? (null, Result.NoTarget, "There's no one to pick.")
                        : (pool[Random.Shared.Next(pool.Count)], Result.Sent, "");
                }
                default:
                    return (null, Result.NoTarget, $"{target} isn't a target. Use a name, #userid, @aim, @random, @randomt, @randomct or @me.");
            }
        }

        if (TryId(target, out var userId, out var steamId))
        {
            var byId = humans.FirstOrDefault(p => steamId != 0 ? p.SteamID == steamId : p.UserId == userId);
            return byId != null ? (byId, Result.Sent, "") : (null, Result.NoTarget, $"No player {target} on the server.");
        }

        var matches = humans.Where(p => p.PlayerName.Contains(target, StringComparison.OrdinalIgnoreCase)).ToList();
        if (matches.Count > 1)
        {
            // A name that's exactly the pattern wins over names that only contain it.
            var exact = matches.Where(p => p.PlayerName.Equals(target, StringComparison.OrdinalIgnoreCase)).ToList();
            if (exact.Count == 1)
                return (exact[0], Result.Sent, "");
            return (null, Result.Ambiguous,
                $"More than one player matches \"{target}\": {string.Join(", ", matches.Select(p => $"{p.PlayerName} (#{p.UserId})"))}. Use their #userid.");
        }
        return matches.Count == 1 ? (matches[0], Result.Sent, "") : (null, Result.NoTarget, $"No player matches \"{target}\".");
    }

    // "#5" (a userid), "#7656…"/"7656…" (a SteamID64) or "STEAM_0:1:…". steamId is 0 for a userid.
    private static bool TryId(string text, out int userId, out ulong steamId)
    {
        userId = 0;
        steamId = 0;
        var bare = text.TrimStart('#');
        if (bare.StartsWith("STEAM_", StringComparison.OrdinalIgnoreCase))
        {
            try
            {
                steamId = ((SteamID)bare).SteamId64;
                return steamId != 0;
            }
            catch (Exception)
            {
                return false;
            }
        }
        if (bare.Length == 17 && ulong.TryParse(bare, out steamId))
            return true;
        steamId = 0;
        return text.StartsWith('#') && int.TryParse(bare, out userId);
    }

    // --- Blocks ---------------------------------------------------------------------

    private bool BlocksReady(CCSPlayerController player, Action<string> reply, out List<Database.Block> blocks)
    {
        if (_blocks.TryGetValue(player.SteamID, out var list) && list != null)
        {
            blocks = list;
            return true;
        }
        if (!_blocks.ContainsKey(player.SteamID))
            LoadBlocks(player.SteamID);
        blocks = [];
        reply(Notice("Your block list is still loading. Try again in a moment."));
        return false;
    }

    private void Block(CCSPlayerController player, string args, Action<string> reply)
    {
        var target = args.Trim();
        if (!TryId(target, out var userId, out var steamId))
        {
            reply(Notice("Usage: /block <#userid|steamid64>. #userid is in css_players or status."));
            return;
        }
        var online = Humans().FirstOrDefault(p => steamId != 0 ? p.SteamID == steamId : p.UserId == userId);
        if (online != null && !CanSee(player, online))
            online = null;
        if (steamId == 0)
        {
            if (online == null)
            {
                reply(Notice($"No player {target} on the server. A SteamID64 works for players who are offline."));
                return;
            }
            steamId = online.SteamID;
        }
        if (steamId == player.SteamID)
        {
            reply(Notice("You can't block yourself."));
            return;
        }
        if (!BlocksReady(player, reply, out var blocks))
            return;
        var name = online?.PlayerName ?? "";
        var shown = name == "" ? steamId.ToString() : name;
        if (blocks.Any(b => b.SteamId == steamId))
        {
            reply(Notice($"You've already blocked {shown}."));
            return;
        }
        if (blocks.Count >= Config.MaxBlocks)
        {
            reply(Notice($"Your block list is full ({Config.MaxBlocks}). /unblock someone first."));
            return;
        }
        var now = DateTime.UtcNow;
        blocks.Add(new Database.Block(steamId, name, now));
        _writer?.Enqueue(new BlockAdd(player.SteamID, steamId, name, now));
        reply(Notice($"Blocked {shown}. They can't send you private messages."));
    }

    private void BlockList(CCSPlayerController player, Action<string> reply)
    {
        if (!BlocksReady(player, reply, out var blocks))
            return;
        if (blocks.Count == 0)
        {
            reply(Notice("You haven't blocked anyone."));
            return;
        }
        reply(Notice($"You've blocked {blocks.Count} {(blocks.Count == 1 ? "player" : "players")}. /unblock <number> to remove one:"));
        for (var i = 0; i < blocks.Count; i++)
        {
            var b = blocks[i];
            reply(Notice(b.Name == "" ? $"{i + 1}. {b.SteamId}" : $"{i + 1}. {b.Name} ({b.SteamId})"));
        }
    }

    private void Unblock(CCSPlayerController player, string args, Action<string> reply)
    {
        if (!BlocksReady(player, reply, out var blocks))
            return;
        if (!int.TryParse(args.Trim(), out var number) || number < 1 || number > blocks.Count)
        {
            reply(Notice(blocks.Count == 0
                ? "You haven't blocked anyone."
                : $"Usage: /unblock <number>, from 1 to {blocks.Count}. /blocklist shows the numbers."));
            return;
        }
        var removed = blocks[number - 1];
        blocks.RemoveAt(number - 1);
        _writer?.Enqueue(new BlockRemove(player.SteamID, removed.SteamId));
        reply(Notice($"Unblocked {(removed.Name == "" ? removed.SteamId.ToString() : removed.Name)}."));
    }

    // --- History --------------------------------------------------------------------

    private void Log(CCSPlayerController sender, CCSPlayerController? recipient, string target, string message, string result) =>
        Log(ChatChannel.Pm, StateOf(sender), recipient, target, message, result);

    private void Log(string channel, PlayerState sender, CCSPlayerController? recipient, string? target, string message, string result)
    {
        if (!Config.History || _writer == null)
            return;
        int? serverId = null;
        try
        {
            serverId = _simpleAdmin?.GetServerId();
        }
        catch (Exception)
        {
        }
        _writer.Enqueue(new MessageRecord(Guid.NewGuid().ToString("N"), DateTime.UtcNow, serverId, Server.MapName ?? "",
            channel, sender, recipient == null ? null : StateOf(recipient), target, message, result));
    }

    [ConsoleCommand("css_whisper_history", "Turns keeping message history on or off")]
    [CommandHelper(usage: "[on|off]", whoCanExecute: CommandUsage.CLIENT_AND_SERVER)]
    [RequiresPermissions("@css/root")]
    public void OnHistoryCommand(CCSPlayerController? player, CommandInfo command)
    {
        var arg = command.GetArg(1).ToLowerInvariant();
        if (arg is not ("on" or "off"))
        {
            command.ReplyToCommand($"[Whisper] History is {(Config.History ? "on" : "off")}. Usage: css_whisper_history <on|off>");
            return;
        }
        Config.History = arg == "on";
        try
        {
            SaveConfig();
            command.ReplyToCommand($"[Whisper] History is now {arg}.");
        }
        catch (Exception ex)
        {
            command.ReplyToCommand($"[Whisper] History is now {arg}, but saving Whisper.json failed: {ex.Message}");
        }
    }

    private void SaveConfig()
    {
        var path = Path.GetFullPath(Path.Combine(ModuleDirectory, "..", "..", "configs", "plugins", ModuleName, $"{ModuleName}.json"));
        var json = JsonSerializer.Serialize(Config, new JsonSerializerOptions
        {
            WriteIndented = true,
            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
        });
        var temp = path + ".tmp";
        File.WriteAllText(temp, json);
        File.Move(temp, path, overwrite: true);
    }
}