using System;

namespace AcDream.Core.Physics.Motion;

/// <summary>
/// R2-Q5 — the <see cref="IInterpretedMotionSink"/> that dispatches the
/// CMotionInterp funnel's retail-ordered motion events STRAIGHT into the
/// entity's motion-table stack via
/// <see cref="AnimationSequencer.PerformMovement"/> (lazy initialize_state +
/// <c>MotionTableManager::PerformMovement</c> 0x0051c0b0).
///
/// <para>
/// This replaces the App-side <c>RemoteMotionSink</c> (deleted): no axis
/// collection, no single-cycle priority pick, no Commit pass, no HasCycle
/// probe, no Run→Walk→Ready missing-cycle chain — retail's
/// <c>GetObjectSequence</c> (0x00522860) + <c>is_allowed</c> decide what
/// plays. Forward locomotion installs the substate cycle (Branch 2);
/// sidesteps resolve by the dat (cycle when authored, else modifier);
/// turns are Branch-4 physics-only modifiers blended over the substate via
/// <c>combine_motion</c>/<c>re_modify</c> — the composition the retired
/// AP-73 row approximated with one cycle.
/// </para>
///
/// <para>
/// The <see cref="TurnApplied"/>/<see cref="TurnStopped"/> callbacks are the
/// interim ObservedOmega seam: the App seeds the remote body's angular
/// velocity from the wire turn so rotation starts the same tick (retail
/// rotates the body from the sequence omega inside the per-tick
/// <c>apply_physics</c> chain — R6 scope; register row). They fire BEFORE
/// the dispatch so a consumer sees the seed even if the dat lacks the
/// modifier entry.
/// </para>
/// </summary>
public sealed class MotionTableDispatchSink : IInterpretedMotionSink
{
    private readonly AnimationSequencer _sequencer;

    /// <summary>Turn-class dispatch observed: (motion, signedSpeed) —
    /// TurnLeft arrives either as the explicit 0x0E command or as
    /// TurnRight + negative speed (adjust_motion wire convention).</summary>
    public Action<uint, float>? TurnApplied { get; set; }

    /// <summary>Turn-class stop observed.</summary>
    public Action? TurnStopped { get; set; }

    public MotionTableDispatchSink(AnimationSequencer sequencer)
    {
        ArgumentNullException.ThrowIfNull(sequencer);
        _sequencer = sequencer;
    }

    private static bool IsTurn(uint motion)
        => (motion & 0xFF000000u) == 0x65000000u && (motion & 0xFFu) is 0x0D or 0x0E;

    public void ApplyMotion(uint motion, float speed)
    {
        if (IsTurn(motion))
            TurnApplied?.Invoke(motion, speed);

        _sequencer.PerformMovement(MotionTableMovement.Interpreted(motion, speed));
    }

    public void StopMotion(uint motion)
    {
        if (IsTurn(motion))
            TurnStopped?.Invoke();

        _sequencer.PerformMovement(MotionTableMovement.StopInterpreted(motion, 1f));
    }
}