namespace BardFrontline.Core;

// One outstanding native request. Cooldown changes alone are insufficient for a cleanse: wait for acknowledgement.
public sealed class RequestGate
{
    public ActionDecision? Pending { get; private set; }
    private double sentAt;
    private ushort beforeSequence;
    private bool sequenceObserved;
    private ushort requestSequence;
    private readonly Dictionary<(Skill, ulong), double> failures = [];
    public string Reason { get; private set; } = "";

    public void Submitted(ActionDecision decision, double now, ushort before, ushort after)
    {
        Pending = decision; sentAt = now; beforeSequence = before;
        sequenceObserved = after != before; requestSequence = after; Reason = "等待动作确认";
    }
    public bool Update(double now, ushort used, ushort handled, bool guardActive, bool cleansingStateChanged, bool ownedCastInProgress = false)
    {
        if (Pending == null) return false;
        if (!sequenceObserved && used != beforeSequence) { sequenceObserved = true; requestSequence = used; }
        var acknowledged = sequenceObserved && unchecked((short)(handled - requestSequence)) >= 0;
        var elapsed = now - sentAt;
        var release = Pending.Skill switch
        {
            Skill.Guard => guardActive || acknowledged && elapsed >= .5,
            Skill.Purify or Skill.WardensPaean => cleansingStateChanged || acknowledged && elapsed >= .5,
            _ => acknowledged && elapsed >= .1,
        };
        if (release) { Pending = null; Reason = ""; return false; }
        if (ownedCastInProgress) return true;
        if (elapsed < 2) return true;
        Fail(Pending, now, "动作确认超时，短暂退避"); Pending = null;
        return false;
    }
    public bool IsBlocked(Skill s, ulong id, double now) => failures.TryGetValue((s, id), out var until) && until > now;
    public void Fail(ActionDecision d, double now, string reason)
    {
        failures[(d.Skill, d.TargetId)] = now + .5; Reason = reason;
        foreach (var key in failures.Where(x => x.Value <= now).Select(x => x.Key).ToArray()) failures.Remove(key);
    }
    public void Reset() { Pending = null; failures.Clear(); Reason = ""; }
}