using System.Numerics;
using AcDream.Core.Net.Packets;

namespace AcDream.Core.Net.Messages;

/// <summary>
/// Outbound <c>GameAction(Jump)</c> message — opcode <c>0xF61B</c>.
/// Sent when the player releases the spacebar to jump. The server uses
/// the extent + velocity to validate the jump and replicate it to nearby
/// clients.
///
/// <para>
/// Wire layout — ports retail's <c>JumpPack::Pack</c> verbatim
/// (<c>0x00516d10</c>, decomp lines ~284934-284963). Confirmed against the
/// Ghidra decompile-by-address bridge during this slice (2026-06-30):
/// </para>
/// <list type="bullet">
///   <item><b>GameAction envelope</b>: u32 0xF7B1, u32 sequence, u32 0xF61B</item>
///   <item><b>f32 extent</b> (0.0-1.0 charge power)</item>
///   <item><b>f32 velocity.x, velocity.y, velocity.z</b></item>
///   <item><b>Position::Pack</b>: u32 cellId, f32 x, f32 y, f32 z,
///         f32 qw, f32 qx, f32 qy, f32 qz (32 bytes)</item>
///   <item><b>Sequences</b>: u16 instance, u16 serverControl,
///         u16 teleport, u16 forcePosition</item>
///   <item><b>Align to 4 bytes</b></item>
/// </list>
///
/// <para>
/// <b>D4 fix.</b> Retail's <c>JumpPack</c> does NOT pack an objectGuid or a
/// spellId, and DOES pack the full <c>Position</c> — the pre-slice code had
/// it backwards (two spurious trailing zero u32s, no Position at all).
/// </para>
/// </summary>
public static class JumpAction
{
    public const uint GameActionOpcode = 0xF7B1u;
    public const uint JumpOpcode       = 0xF61Bu;

    public static byte[] Build(
        uint       gameActionSequence,
        float      extent,
        Vector3    velocity,
        uint       cellId,
        Vector3    position,
        Quaternion rotation,
        ushort     instanceSequence,
        ushort     serverControlSequence,
        ushort     teleportSequence,
        ushort     forcePositionSequence)
    {
        var w = new PacketWriter(80);

        w.WriteUInt32(GameActionOpcode);
        w.WriteUInt32(gameActionSequence);
        w.WriteUInt32(JumpOpcode);

        w.WriteFloat(extent);
        w.WriteFloat(velocity.X);
        w.WriteFloat(velocity.Y);
        w.WriteFloat(velocity.Z);

        // --- Position::Pack (0x005a9640): cellId + Frame::Pack (32 bytes) ---
        w.WriteUInt32(cellId);
        w.WriteFloat(position.X);
        w.WriteFloat(position.Y);
        w.WriteFloat(position.Z);
        // Quaternion wire order: W, X, Y, Z
        w.WriteFloat(rotation.W);
        w.WriteFloat(rotation.X);
        w.WriteFloat(rotation.Y);
        w.WriteFloat(rotation.Z);

        w.WriteUInt16(instanceSequence);
        w.WriteUInt16(serverControlSequence);
        w.WriteUInt16(teleportSequence);
        w.WriteUInt16(forcePositionSequence);

        w.AlignTo4();

        return w.ToArray();
    }
}