acdream/src/AcDream.Core.Net/Messages/ClientCommandRequests.cs

using System.Buffers.Binary;
using System.Text;

namespace AcDream.Core.Net.Messages;

/// <summary>
/// Wire builders for game actions initiated by retail client-owned chat
/// commands.  Keeping this family separate from generic object interaction
/// makes the command boundary explicit while reusing the normal
/// <c>0xF7B1</c> game-action envelope.
/// </summary>
public static class ClientCommandRequests
{
    public const uint MarketplaceOpcode = 0x028Du;
    public const uint PkArenaOpcode = 0x0027u;
    public const uint PkLiteArenaOpcode = 0x0026u;
    public const uint HouseRecallOpcode = 0x0262u;
    public const uint MansionRecallOpcode = 0x0278u;
    public const uint QueryAgeOpcode = 0x01C2u;
    public const uint QueryBirthOpcode = 0x01C4u;
    public const uint ConfirmationResponseOpcode = 0x0275u;
    public const uint SuicideOpcode = 0x0279u;
    public const uint SetAfkModeOpcode = 0x000Fu;
    public const uint SetAfkMessageOpcode = 0x0010u;
    public const uint EmoteOpcode = 0x01DFu;
    public const uint AddFriendOpcode = 0x0018u;
    public const uint RemoveFriendOpcode = 0x0017u;
    public const uint ClearFriendsOpcode = 0x0025u;
    public const uint ModifyCharacterSquelchOpcode = 0x0058u;
    public const uint ModifyAccountSquelchOpcode = 0x0059u;
    public const uint ModifyGlobalSquelchOpcode = 0x005Bu;
    public const uint ClearConsentOpcode = 0x0216u;
    public const uint DisplayConsentOpcode = 0x0217u;
    public const uint RemoveConsentOpcode = 0x0218u;
    public const uint SetDesiredComponentLevelOpcode = 0x0224u;
    public const uint LegacyFriendsOpcode = 0xF7CDu;

    // Named-retail anchors:
    //   CM_Character::Event_TeleToMarketplace @ 0x006A1C20
    //   CM_Character::Event_TeleToPKArena     @ 0x006A1CB0
    //   CM_Character::Event_TeleToPKLArena    @ 0x006A1D40
    //   CM_House::Event_TeleToHouse_Event     @ 0x006AAFA0
    //   CM_House::Event_TeleToMansion_Event   @ 0x006AB030
    public static byte[] BuildMarketplace(uint sequence) =>
        BuildParameterless(sequence, MarketplaceOpcode);

    public static byte[] BuildPkArena(uint sequence) =>
        BuildParameterless(sequence, PkArenaOpcode);

    public static byte[] BuildPkLiteArena(uint sequence) =>
        BuildParameterless(sequence, PkLiteArenaOpcode);

    public static byte[] BuildHouseRecall(uint sequence) =>
        BuildParameterless(sequence, HouseRecallOpcode);

    public static byte[] BuildMansionRecall(uint sequence) =>
        BuildParameterless(sequence, MansionRecallOpcode);

    // Named-retail anchors:
    //   CM_Character::Event_QueryAge   @ 0x006A1620
    //   CM_Character::Event_QueryBirth @ 0x006A16F0
    public static byte[] BuildQueryAge(uint sequence, uint objectId = 0u) =>
        BuildObjectQuery(sequence, QueryAgeOpcode, objectId);

    public static byte[] BuildQueryBirth(uint sequence, uint objectId = 0u) =>
        BuildObjectQuery(sequence, QueryBirthOpcode, objectId);

    // CM_Character::Event_ConfirmationResponse @ 0x006A1210.
    public static byte[] BuildConfirmationResponse(
        uint sequence,
        uint confirmationType,
        uint contextId,
        bool accepted)
    {
        byte[] body = new byte[24];
        BinaryPrimitives.WriteUInt32LittleEndian(body, InteractRequests.GameActionEnvelope);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), sequence);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), ConfirmationResponseOpcode);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), confirmationType);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(16), contextId);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(20), accepted ? 1u : 0u);
        return body;
    }

    // CM_Character::Event_Suicide @ 0x006A1B00.
    public static byte[] BuildSuicide(uint sequence) =>
        BuildParameterless(sequence, SuicideOpcode);

    // CM_Communication::Event_SetAFKMode @ 0x006A3EE0.
    public static byte[] BuildSetAfkMode(uint sequence, bool away) =>
        BuildUInt32(sequence, SetAfkModeOpcode, away ? 1u : 0u);

    // CM_Communication::Event_SetAFKMessage @ 0x006A4440.
    public static byte[] BuildSetAfkMessage(uint sequence, string message) =>
        BuildString(sequence, SetAfkMessageOpcode, message);

    // CM_Communication::Event_Emote @ 0x006A4120.
    public static byte[] BuildEmote(uint sequence, string message) =>
        BuildString(sequence, EmoteOpcode, message);

    // CM_Social::Event_AddFriend/RemoveFriend/ClearFriends
    // @ 0x006A5C10 / 0x006A5650 / 0x006A55C0.
    public static byte[] BuildAddFriend(uint sequence, string name) =>
        BuildString(sequence, AddFriendOpcode, name);

    public static byte[] BuildRemoveFriend(uint sequence, uint friendId) =>
        BuildUInt32(sequence, RemoveFriendOpcode, friendId);

    public static byte[] BuildClearFriends(uint sequence) =>
        BuildParameterless(sequence, ClearFriendsOpcode);

    // Proto_UI::SendFriendsCommand @ 0x00546C50 is a control message,
    // not a 0xF7B1 GameAction. Command zero requests the legacy listing.
    public static byte[] BuildLegacyFriendsCommand(uint command, string name)
    {
        byte[] packedName = PackString16L(name);
        byte[] body = new byte[8 + packedName.Length];
        BinaryPrimitives.WriteUInt32LittleEndian(body, LegacyFriendsOpcode);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), command);
        packedName.CopyTo(body, 8);
        return body;
    }

    // CM_Communication::Event_ModifyCharacterSquelch @ 0x006A42D0.
    public static byte[] BuildModifyCharacterSquelch(
        uint sequence,
        bool add,
        uint characterId,
        string name,
        uint messageType)
    {
        byte[] packedName = PackString16L(name);
        byte[] body = CreateBody(sequence, ModifyCharacterSquelchOpcode, 12 + packedName.Length);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), add ? 1u : 0u);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(16), characterId);
        packedName.CopyTo(body, 20);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(20 + packedName.Length), messageType);
        return body;
    }

    // CM_Communication::Event_ModifyAccountSquelch @ 0x006A41E0.
    public static byte[] BuildModifyAccountSquelch(uint sequence, bool add, string name)
    {
        byte[] packedName = PackString16L(name);
        byte[] body = CreateBody(sequence, ModifyAccountSquelchOpcode, 4 + packedName.Length);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), add ? 1u : 0u);
        packedName.CopyTo(body, 16);
        return body;
    }

    // CM_Communication::Event_ModifyGlobalSquelch @ 0x006A3D00.
    public static byte[] BuildModifyGlobalSquelch(uint sequence, bool add, uint messageType)
    {
        byte[] body = CreateBody(sequence, ModifyGlobalSquelchOpcode, 8);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), add ? 1u : 0u);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(16), messageType);
        return body;
    }

    // CM_Character consent events @ 0x006A1180 / 0x006A1360 / 0x006A2C10.
    public static byte[] BuildClearConsent(uint sequence) =>
        BuildParameterless(sequence, ClearConsentOpcode);

    public static byte[] BuildDisplayConsent(uint sequence) =>
        BuildParameterless(sequence, DisplayConsentOpcode);

    public static byte[] BuildRemoveConsent(uint sequence, string name) =>
        BuildString(sequence, RemoveConsentOpcode, name);

    // CM_Character::Event_SetDesiredComponentLevel @ 0x006A2350.
    public static byte[] BuildSetDesiredComponentLevel(
        uint sequence, uint componentId, uint amount)
    {
        byte[] body = CreateBody(sequence, SetDesiredComponentLevelOpcode, 8);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), componentId);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(16), amount);
        return body;
    }

    private static byte[] BuildParameterless(uint sequence, uint opcode)
    {
        byte[] body = new byte[12];
        BinaryPrimitives.WriteUInt32LittleEndian(body, InteractRequests.GameActionEnvelope);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), sequence);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), opcode);
        return body;
    }

    private static byte[] BuildUInt32(uint sequence, uint opcode, uint value)
    {
        byte[] body = CreateBody(sequence, opcode, 4);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), value);
        return body;
    }

    private static byte[] BuildString(uint sequence, uint opcode, string value)
    {
        byte[] packed = PackString16L(value);
        byte[] body = CreateBody(sequence, opcode, packed.Length);
        packed.CopyTo(body, 12);
        return body;
    }

    private static byte[] CreateBody(uint sequence, uint opcode, int payloadLength)
    {
        byte[] body = new byte[12 + payloadLength];
        BinaryPrimitives.WriteUInt32LittleEndian(body, InteractRequests.GameActionEnvelope);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), sequence);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), opcode);
        return body;
    }

    private static byte[] PackString16L(string value)
    {
        ArgumentNullException.ThrowIfNull(value);
        byte[] data = Encoding.GetEncoding(1252).GetBytes(value);
        if (data.Length > ushort.MaxValue)
            throw new ArgumentException("String too long for String16L.", nameof(value));
        int unpadded = 2 + data.Length;
        byte[] packed = new byte[(unpadded + 3) & ~3];
        BinaryPrimitives.WriteUInt16LittleEndian(packed, (ushort)data.Length);
        data.CopyTo(packed, 2);
        return packed;
    }

    private static byte[] BuildObjectQuery(uint sequence, uint opcode, uint objectId)
    {
        byte[] body = new byte[16];
        BinaryPrimitives.WriteUInt32LittleEndian(body, InteractRequests.GameActionEnvelope);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(4), sequence);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(8), opcode);
        BinaryPrimitives.WriteUInt32LittleEndian(body.AsSpan(12), objectId);
        return body;
    }
}