using Ananta.SDK.Network;
using Ananta.SDK.Rpc;
using Ananta.Server.ClientData;
using Ananta.Server.ClientData.Client4229938;
using Ananta.Server.Configuration;
using Ananta.Server.Protocol.Client4229938;
using SceneMethods = Ananta.Server.RpcTypes.Client4229938.Methods.GameScene;

namespace Ananta.Server.Handlers.Game;

/// <summary>
/// AskMetroGadgetIds(67809129) — the missing half of the metro carriages.
///
/// What the client does: it builds the LightRail prefab on its own (see the captured hierarchy
/// <c>LightRail_4_405/carriage1|2/Seats/Gadgets_888_LightRailChair03_*</c>), then asks the server
/// which gadget instance ids belong to that train. Every SpoonSlotComponent on a seat needs a
/// gadget hold before it yields a "sit down" button, and the hold comes from this reply.
///
/// Before 2026-09-23 this method had no handler at all, so the answer was the typed-default empty
/// list (see the log line "unimplemented AskMetroGadgetIds -> typed-default list7-empty 2b"), which
/// is why the seats inside our carriages stay inert while AnantaTrainSeatLoader.exe can wake them
/// up by calling SpoonSlotComponent.Init() directly through frida.
///
/// Option A (implemented here): hand back invented but stable ids from the server's own 9.5e12
/// gadget band. The client only needs an id to bind the local seat slot to. If seats still stay
/// dead, the fallback is option B — really spawn the chairs through SyncGadgetAdd(68843189) with
/// the LightRailChair pathIds (843740076 / 1058671153 / 267309514 / 1181678445, iScale must be 0)
/// and return those instance ids instead.
///
/// Rollback: <c>world.content.metroGadgets.enabled = false</c>.
/// </summary>
internal sealed partial class GameRouter
{
    [Handler(MethodId.AskMetroGadgetIds)]
    private async Task OnAskMetroGadgetIds(Connection conn, UxRpcMessage msg)
    {
        var cfg = PrivateServerConfigStore.Current.World.Content.MetroGadgets;

        if (!msg.TryGetArgs<SceneMethods.AskMetroGadgetIdsArgs4229938>(out var args) || args is null)
        {
            conn.Log.Warn($"[METROG] AskMetroGadgetIds undecodable bytes={msg.Body.Length} " +
                          $"hex={(msg.Body.Length > 0 ? System.Convert.ToHexString(msg.Body, 0, System.Math.Min(msg.Body.Length, 16)) : "-")}");
            await conn.ReturnAsync(msg, new List<SceneMethods.MetroCarriageGadgetInfos>());
            return;
        }

        var metroId = args.metroId;

        // One answer entry per carriage, each holding exactly that carriage's seat count:
        // the client walks its own carriages in order and hands entry[i] to carriage[i], and a
        // count mismatch silently drops the whole carriage (verified 2026-09-23 — our first version
        // answered 6 ids for every carriage and only carriage1, which really has 6 seats, woke up).
        var perCarriage = new List<int>();
        var composition = "";
        if (cfg.UseTrainConfig
            && global::Ananta.Server.ClientData.Client4229938.MetroCarriageCatalog4229938.TryGetCarriageTemplates(metroId, out var templates)
            && templates.Length > 0)
        {
            var unknown = new System.Collections.Generic.List<int>();
            var borrowed = new System.Collections.Generic.List<int>();
            foreach (var template in templates)
            {
                var known = cfg.SeatsByCarriageTemplate.TryGetValue(template, out var configured);
                int seats;
                if (known)
                {
                    seats = configured;
                }
                else
                {
                    unknown.Add(template);
                    // 同一车型（Vehicle01/Head、Vehicle03/End …）的座位数应当一致 —— 没采过的模板
                    // 先借用同车型已配好的那个值，比无脑退化成 defaultCarriageSeats 更接近真值。
                    var cls = RailCarriageCatalog4229938.LayoutClassOf((uint)template);
                    var sibling = cls is null ? null : FindSiblingSeats(cfg, cls, conn);
                    if (sibling is not null)
                        borrowed.Add(template);
                    seats = sibling ?? cfg.DefaultCarriageSeats;
                }
                perCarriage.Add(System.Math.Clamp(seats, 0, 64));
            }
            composition = "tpl[" + string.Join(",", templates) + "] seats[" + string.Join(",", perCarriage) + "]";

            // ⛔ 座位数只对得上「编组模板 id」在 seatsByCarriageTemplate 里有条目的车厢。
            // 查不到就退化成 defaultCarriageSeats（默认 6）。
            // 实测 2026-09-27 15:13：1/2/3 号线的车（tpl 10,2,2,2,3 与 11,7,7,7,8）
            // 全部命中这条退化路径，只有 4 号线的 tpl 4/5/9 是真实值。
            //
            // ★★ 2026-09-28 受控对照 + 症状订正（原来这里写"整节车厢被客户端静默丢弃、座位按不出坐下"，
            //    与客户端实际报出来的东西不符，会把人带偏）：
            //   · 客户端唯一喊出来的错是 **MGAGadgets 槽**（`Metro/Gadget.json data mismatch with
            //     MGAGadgets slot, the slot count is 1 and the gadget count is 0`），
            //     调用栈是 `LoadMoveGroundArea() → OnMoveGroundAreaLoaded → ActivateMGAGadgets()`
            //     —— 车厢自己的 MoveGroundArea（MGA）gadget 没绑上，不是座位。
            //   · `mismatch with **Seats** slot` 那条串在 3 个会话里命中 **0 次** ⇒ 座位检查从未触发。
            //   · 一局内对照：metroId=400..405（4 号线，模板已配）被问 8 次，MGA 报错 **0**；
            //     1/2/3 号线（模板未配）报 50 条。三局日志里报错点名的列车**一辆 4 号线都没有**。
            //   · 线上本身干净：38 次 INVOKE / 38 次 RETURN，全 error=0，延迟 5–10ms，
            //     body 267B（5 车厢×6）或 145B（3 车厢 4+6+6）⇒ 不是协议问题。
            //   ⇒ 模板未配 ⇒ 退化的 6 与真值不符 ⇒ 该车厢的 gadget infos 被丢 ⇒ MGA 拿到 0 个。
            //     所以"必须把真座位数补上"这个结论不变，但**症状描述以 MGA 为准**。
            //     真值只在 prefab 里（任何 JSON 都没有），只能进游戏数，或用 defaultCarriageSeats
            //     做零编译 A/B 反推。见硬规则 212 备注。
            // ⇒ 这里必须喊出来，否则日志看起来"一切正常"。
            if (unknown.Count > 0)
            {
                var names = unknown.Select(t => RailCarriageCatalog4229938.Describe((uint)t));
                conn.Log.Warn($"[METROG] metroId={metroId} 编组模板 {string.Join(",", unknown)} " +
                              $"（车型 {string.Join(", ", names)}）在 metroGadgets.seatsByCarriageTemplate " +
                              $"里没有条目 ⇒ " +
                              (borrowed.Count > 0
                                  ? $"{string.Join(",", borrowed)} 借用了同车型已配值，" +
                                    $"其余退化成 defaultCarriageSeats={cfg.DefaultCarriageSeats}"
                                  : $"退化成 defaultCarriageSeats={cfg.DefaultCarriageSeats}") +
                              $"。客户端实际报的是 MGAGadgets 槽对不上" +
                              $"（Metro/Gadget.json data mismatch with MGAGadgets slot, slot count is 1 / " +
                              $"gadget count is 0，经 LoadMoveGroundArea → ActivateMGAGadgets 触发；" +
                              $"Seats 槽那条报错 3 个会话里一次都没出现过）。" +
                              $"补法：进游戏站到该线路的车上，跑 TrainSeatLoader 的 trainhier，" +
                              $"数每节车厢 Seats 下的 LightRailChair 个数，按模板 id 填进配置" +
                              $"（13 个模板按车型归并只有 8 种布局，采一趟 1/2 号线就能覆盖 Vehicle01 的头/中/尾）。");
            }
        }
        else
        {
            var carriages = System.Math.Clamp(cfg.Carriages, 0, 32);
            var flat = System.Math.Clamp(cfg.SeatsPerCarriage, 0, 64);
            for (var i = 0; i < carriages; i++)
                perCarriage.Add(flat);
            composition = $"flat {carriages}x{flat}";
        }

        if (!cfg.Enabled || cfg.LogOnly || cfg.IdBase == 0UL || perCarriage.Count == 0 || perCarriage.All(n => n == 0))
        {
            conn.Log.Info($"[METROG] AskMetroGadgetIds metroId={metroId} -> empty " +
                          $"(enabled={cfg.Enabled} logOnly={cfg.LogOnly} {composition})");
            await conn.ReturnAsync(msg, new List<SceneMethods.MetroCarriageGadgetInfos>());
            return;
        }

        // Deterministic: the same train always gets the same ids, so a repeated ask (the client
        // re-asks every few seconds while a train is near) never reshuffles the seats.
        var result = new List<SceneMethods.MetroCarriageGadgetInfos>(perCarriage.Count);
        ulong total = 0UL;
        for (var c = 0; c < perCarriage.Count; c++)
        {
            var seats = perCarriage[c];
            var inner = new List<ulong>(seats);
            for (var s = 0; s < seats; s++)
                inner.Add(cfg.IdBase
                          + (ulong)((long)metroId * 10000L)
                          + (ulong)(c * 100)
                          + (ulong)s);

            total += (ulong)seats;
            result.Add(new SceneMethods.MetroCarriageGadgetInfos
            {
                InnerGadgetIds = inner,
                OuterGadgetIds = cfg.IncludeOuter ? new List<ulong>(inner) : new List<ulong>(),
            });
        }

        var firstIds = result[0].InnerGadgetIds;
        var firstId = firstIds is { Count: > 0 } ? firstIds[0].ToString() : "-";
        conn.Log.Info($"[METROG] AskMetroGadgetIds metroId={metroId} -> {result.Count} carriage(s), {total} seat id(s), " +
                      $"{composition}, first={firstId} outer={cfg.IncludeOuter}");
        await conn.ReturnAsync(msg, result);
    }

    private static readonly HashSet<string> WarnedSeatConflicts = new();
    private static readonly object SeatConflictLock = new();

    /// <summary>
    /// 同车型（同一 <c>RailCarriageConfig</c> 布局类）里有没有已经配好座位数的兄弟模板？
    /// 有就借用它的值 —— 比退化成 defaultCarriageSeats 更接近真值。
    /// ⛑ <b>必须按 key 升序取第一个</b>：<c>Dictionary</c> 的遍历顺序没有保证，同车型存在
    /// 多个已配值时会取到随机的那个（见 <see cref="WarnSeatConflict"/>）。
    /// </summary>
    private static int? FindSiblingSeats(MetroGadgetSettings cfg, string layoutClass, Connection conn)
    {
        int? first = null;
        var distinct = new SortedSet<int>();
        foreach (var kv in cfg.SeatsByCarriageTemplate.OrderBy(k => k.Key))
        {
            if (RailCarriageCatalog4229938.LayoutClassOf((uint)kv.Key) != layoutClass)
                continue;
            distinct.Add(kv.Value);
            first ??= kv.Value;
        }
        if (distinct.Count > 1)
            WarnSeatConflict(layoutClass, distinct, conn);
        return first;
    }

    /// <summary>
    /// 同一布局类里配了<b>不一样</b>的座位数 —— 一定是某次实测数错了，喊出来（每条只喊一次）。
    /// 2026-09-27 现况：Vehicle03/End 同时有 tpl4=4 与 tpl9=6，而两者
    /// <c>TemplateName</c>(Vehicle03/CarriageOnEnd) 与 <c>ViewModelName</c>(View_Blue_End)
    /// <b>完全相同</b>，只差 <c>IsRevert</c>（镜像）⇒ 座位数本该一样，现在必有一个是错的。
    /// </summary>
    private static void WarnSeatConflict(string layoutClass, SortedSet<int> values, Connection conn)
    {
        lock (SeatConflictLock)
        {
            if (!WarnedSeatConflicts.Add(layoutClass))
                return;
        }
        conn.Log.Warn("[METROG] ⛔ 座位表自相矛盾：布局类 " + layoutClass +
                      " 在 metroGadgets.seatsByCarriageTemplate 里配了 " + string.Join(" / ", values) +
                      " 多个不同值 —— 同一车型的车厢座位数本该一致，必有一次实测数错，" +
                      "当前只按模板 id 升序取第一个用。请进游戏跑 TrainSeatLoader 的 trainhier 重新数一遍。");
    }
}