namespace Aeshnidae.Junk;

/// <summary>
/// /junk - destroy items in your own packs by name.
///
/// ACE's @delete takes the one object you have selected; emptying a pack of
/// sixty salvage bags that way is sixty selections. This walks the main pack and
/// the side packs, matches on the item name and consumes each match the same way
/// the server consumes a spell component - inventory, client and encumbrance all
/// updated - so nothing is left on the floor to decay.
/// </summary>
public static class Commands
{
    [CommandHandler("junk", AccessLevel.Developer, CommandHandlerFlag.RequiresWorld, 1,
        "Destroy every unequipped item in your packs whose name contains the text.",
        "/junk <text> [count]\n" +
        "/junk \"Salvage (\"      every salvage bag, main pack and side packs\n" +
        "/junk salvage 10      at most ten of them\n" +
        "/junk =Pyreal         the whole name only: the coins, not the Pyreal Scarabs\n" +
        "Packs themselves, equipped items and anything you are wielding are never touched.")]
    public static void HandleJunk(Session session, params string[] parameters)
    {
        var player = session?.Player;

        if (player is null)
        {
            ModManager.Log($"[{Mod.Name}] /junk needs a player; from the console use junk-from <player> <text>.");
            return;
        }

        Junk(session, player, parameters);
    }

    /// <summary>
    /// The console form: the same thing done to an online player's packs. For the
    /// admin gear that should not be in a pack at all - the Sonic Screwdriver that
    /// unlocks anything (2026-09-22) - without asking the player to do it themselves.
    /// </summary>
    [CommandHandler("junk-from", AccessLevel.Admin, CommandHandlerFlag.None, 2,
        "Destroy every unequipped item in an online player's packs whose name contains the text. Console-safe.",
        "/junk-from <player> <text> [count]      same rules as /junk; the player is told what went")]
    public static void HandleJunkFrom(Session session, params string[] parameters)
    {
        var target = PlayerManager.GetOnlinePlayer(parameters[0]);

        if (target is null)
        {
            Reply(session, $"'{parameters[0]}' is not online.");
            return;
        }

        Junk(session, target, parameters.Skip(1).ToArray(), tellPlayer: true);
    }

    private static void Junk(Session? session, Player player, string[] parameters, bool tellPlayer = false)
    {
        // A trailing number is the count; everything before it is the name text,
        // so "/junk Salvage (" needs no quoting.
        var words = parameters.ToList();
        var limit = int.MaxValue;

        if (words.Count > 1 && int.TryParse(words[^1], out var count))
        {
            if (count < 1)
            {
                Reply(session, "The count must be at least 1.");
                return;
            }

            limit = count;
            words.RemoveAt(words.Count - 1);
        }

        var text = string.Join(' ', words).Trim().Trim('"');

        // A leading '=' asks for the whole name: "=Pyreal" is the coins and
        // leaves the Pyreal Scarabs, which "Pyreal" would take too.
        var exact = text.StartsWith('=');
        if (exact)
            text = text[1..].Trim();

        if (text.Length < Mod.Settings.MinimumTextLength)
        {
            Reply(session, $"Usage: /junk <text> [count] - the text must be at least {Mod.Settings.MinimumTextLength} characters, so a slip cannot empty the pack.");
            return;
        }

        var matches = new List<WorldObject>();

        foreach (var item in player.Inventory.Values)
        {
            if (item is Container pack)
            {
                // A side pack's contents are fair game; the pack itself never is.
                foreach (var inner in pack.Inventory.Values)
                    if (Matches(inner, text, exact))
                        matches.Add(inner);

                continue;
            }

            if (Matches(item, text, exact))
                matches.Add(item);
        }

        if (matches.Count == 0)
        {
            Reply(session, exact ? $"Nothing in your packs is named \"{text}\"." : $"Nothing in your packs is named like \"{text}\".");
            return;
        }

        var destroyed = 0;
        var failed = 0;
        var names = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);

        foreach (var item in matches.Take(limit))
        {
            bool gone;

            try
            {
                gone = player.TryConsumeFromInventoryWithNetworking(item);
            }
            catch (Exception ex)
            {
                gone = false;
                ModManager.Log($"[{Mod.Name}] /junk could not destroy 0x{item.Guid}:{item.Name}: {ex}", ModManager.LogLevel.Error);
            }

            if (!gone)
            {
                failed++;
                continue;
            }

            destroyed++;
            names[item.Name ?? "?"] = names.GetValueOrDefault(item.Name ?? "?") + 1;
        }

        var summary = string.Join(", ", names.OrderByDescending(n => n.Value).Select(n => n.Value == 1 ? n.Key : $"{n.Value} x {n.Key}"));
        var left = matches.Count - destroyed - failed;

        var report = $"Destroyed {destroyed} item(s): {summary}." +
                     (failed > 0 ? $" {failed} could not be removed (see the server log)." : "") +
                     (left > 0 ? $" {left} more match; raise the count to take them too." : "");

        Reply(session, (tellPlayer ? $"{player.Name}: " : "") + report);

        if (tellPlayer && destroyed > 0)
            player.SendMessage($"Removed from your packs by the server: {summary}.");

        // The same trail @delete leaves, so a purge is never a mystery in #audit.
        if (destroyed > 0)
            PlayerManager.BroadcastToAuditChannel(player, $"{player.Name} junked {destroyed} item(s) named like \"{text}\": {summary}");
    }

    private static bool Matches(WorldObject item, string text, bool exact)
    {
        if (item.Name is null || item is Container)
            return false;

        return exact
            ? item.Name.Equals(text, StringComparison.OrdinalIgnoreCase)
            : item.Name.Contains(text, StringComparison.OrdinalIgnoreCase);
    }

    [CommandHandler("junk-reload", AccessLevel.Admin, CommandHandlerFlag.None, 0,
        "Restart the Aeshnidae.Junk mod, re-reading Settings.json.",
        "/junk-reload")]
    public static void HandleReload(Session session, params string[] parameters)
    {
        var container = Mod.Container;
        if (container is null)
        {
            Reply(session, $"{Mod.Name} is not loaded.");
            return;
        }

        container.Restart();
        Reply(session, $"{Mod.Name} restarted.");
    }

    /// <summary>
    /// The client renders an embedded newline as a music note, so a multi-line
    /// message has to go out as one SendMessage per line.
    /// </summary>
    private static void Reply(Session? session, string message)
    {
        if (session?.Player is null)
        {
            ModManager.Log(message);
            return;
        }

        foreach (var line in (message ?? "").Split('\n'))
        {
            var text = line.TrimEnd('\r');

            if (!string.IsNullOrWhiteSpace(text))
                session.Player.SendMessage(text);
        }
    }
}