// Adapted from the user-owned AI body's visual discovery rules only.
// Candidate casualty identities are local perception work, never delivered HQ knowledge.
class ERR_HQBodyCandidate
{
 IEntity Corpse;
 ref ERR_HQStatusSampler Roster;
 string SourceId;
 int Slot = -1;
 int Strength;
 bool Confirmed;
 float ReportAfter;
}

class ERR_HQBodyScan
{
 SCR_AIGroup Group;
 float NextScan;
 float LastAsked = -1;
 int Cursor;
}

class ERR_HQBodyRules
{
 static bool InView(float distance, float facing)
 {
  return ERR_HQMemoryRules.Finite(distance) && ERR_HQMemoryRules.Finite(facing)
   && distance >= 0 && distance <= 60 && (distance <= 12 || facing >= 0.5);
 }
 static bool Clear(float fraction, bool hitBody)
 {
  return ERR_HQMemoryRules.Finite(fraction) && fraction >= 0 && (fraction >= 1 || hitBody);
 }
}

class ERR_HQBodyObserver
{
 protected ref array<ref ERR_HQBodyCandidate> m_Roster = {};
 protected ref array<ref ERR_HQBodyCandidate> m_Bodies = {};
 protected ref array<ref ERR_HQBodyScan> m_Groups = {};
 protected float m_NextBudget;
 protected float m_Now = -1;
 protected int m_Traces;
 protected int m_RosterCursor;
 protected bool m_CapLogged;

 protected bool OwnedPhysical(SCR_AIGroup group)
 {
  ERR_GameMode mode = ERR_GameMode.Get();
  if (!mode || !group || group.GetFaction() != mode.EnemyFaction()) return false;
  ERR_ForceRecord force = mode.Forces().FindGroup(group);
  return force && force.Physical && !force.Eliminated;
 }
 protected bool Dead(IEntity actor)
 {
  ChimeraCharacter character = ChimeraCharacter.Cast(actor);
  return character && character.GetCharacterController()
   && character.GetCharacterController().GetLifeState() == ECharacterLifeState.DEAD;
 }
 protected void Cap()
 {
  if (m_CapLogged) return;
  m_CapLogged = true;
  Print("Rereintroduced [body observer]: finite local registry limit reached; no discovery work added.");
 }
 protected void Prune()
 {
  for (int i = m_Bodies.Count() - 1; i >= 0; i--)
   if (!m_Bodies[i].Corpse || m_Bodies[i].Confirmed || !Dead(m_Bodies[i].Corpse)) m_Bodies.Remove(i);
  for (int i = m_Roster.Count() - 1; i >= 0; i--)
   if (!m_Roster[i].Corpse) m_Roster.Remove(i);
  for (int i = m_Groups.Count() - 1; i >= 0; i--)
   if (!m_Groups[i].Group) m_Groups.Remove(i);
 }
 void RegisterGroup(SCR_AIGroup group, ERR_HQStatusSampler sampler)
 {
  if (!Replication.IsServer() || !OwnedPhysical(group) || !sampler || !sampler.OwnsRoster(group)) return;
  Prune();
  bool known;
  foreach (ERR_HQBodyScan scan : m_Groups) if (scan.Group == group) known = true;
  if (!known)
  {
   if (m_Groups.Count() >= 128) { Cap(); return; }
   ERR_HQBodyScan created = new ERR_HQBodyScan(); created.Group = group;
   m_Groups.Insert(created);
  }
  // Slot identity comes only from the immutable sampler bind, never current agent order.
  for (int member = 0; member < sampler.InitialStrength(); member++)
  {
   IEntity actor = sampler.InitialMember(member);
   if (!sampler.CanAttribute(member, actor)) continue;
   bool found;
   foreach (ERR_HQBodyCandidate entry : m_Roster) if (entry.Corpse == actor) found = true;
   if (found) continue;
   if (m_Roster.Count() >= 128) { Cap(); return; }
   ERR_HQBodyCandidate candidate = new ERR_HQBodyCandidate(); candidate.Corpse = actor;
   candidate.Roster = sampler; candidate.SourceId = sampler.InitialSourceId();
   candidate.Slot = member; candidate.Strength = sampler.InitialStrength();
   m_Roster.Insert(candidate);
  }
 }
 void TickBudget(float now)
 {
  if (!Replication.IsServer() || !ERR_HQMemoryRules.Finite(now) || now < 0 || now < m_Now) return;
  m_Now = now;
  if (now < m_NextBudget) return;
  m_NextBudget = now + 5000;
  m_Traces = 12;
  Prune();
  // No position reads, messages or callbacks here: death only makes a local LOS candidate.
  // Rotate the finite candidate window so sixteen remote corpses cannot hide later losses.
  m_Bodies.Clear();
  int total = m_Roster.Count();
  for (int visited = 0; visited < total; visited++)
  {
   if (m_Bodies.Count() >= 16) { Cap(); break; }
   if (m_RosterCursor >= total) m_RosterCursor = 0;
   ERR_HQBodyCandidate candidate = m_Roster[m_RosterCursor++];
   if (!candidate.Corpse || candidate.Confirmed || m_Bodies.Contains(candidate) || !Dead(candidate.Corpse)) continue;
   m_Bodies.Insert(candidate);
  }
 }
 protected bool Visible(IEntity observer, IEntity body, out vector observedPosition)
 {
  if (m_Traces <= 0 || !observer || !body || !ERR_Actors.CanFight(observer)
   || CompartmentAccessComponent.GetVehicleIn(observer)) return false;
  vector bodyPosition = body.GetOrigin();
  vector observerPosition = observer.GetOrigin();
  vector delta = bodyPosition - observerPosition;
  float distance = delta.Length();
  delta[1] = 0;
  vector transform[4]; observer.GetWorldTransform(transform);
  vector forward = transform[2]; forward[1] = 0;
  float facing;
  if (delta.Length() > 0.01 && forward.Length() > 0.01)
   facing = vector.Dot(forward.Normalized(), delta.Normalized());
  if (!ERR_HQBodyRules.InView(distance, facing)) return false;
  TraceParam trace = new TraceParam();
  trace.Start = observerPosition + "0 1.5 0";
  trace.End = bodyPosition + "0 0.3 0";
  trace.Exclude = observer;
  trace.Flags = TraceFlags.ENTS | TraceFlags.WORLD;
  m_Traces--;
  float fraction = GetGame().GetWorld().TraceMove(trace, null);
  if (!ERR_HQBodyRules.Clear(fraction, trace.TraceEnt == body)) return false;
  observedPosition = bodyPosition;
  return true;
 }
 protected ERR_HQBodyScan OldestDue(float now)
 {
  ERR_HQBodyScan selected;
  foreach (ERR_HQBodyScan scan : m_Groups)
  {
   // Recently requesting groups share turns; inactive callers cannot reserve work forever.
   if (!scan.Group || now < scan.NextScan || scan.LastAsked < 0 || now - scan.LastAsked > 5000) continue;
   if (!OwnedPhysical(scan.Group) || scan.Group.GetPlayerCount(true) > 0) continue;
   if (!selected || scan.NextScan < selected.NextScan) selected = scan;
  }
  return selected;
 }
 bool Observe(SCR_AIGroup group, float now, out ERR_HQReport report)
 {
  report = null;
  if (!Replication.IsServer() || !ERR_HQMemoryRules.Finite(now) || now < m_Now || now < 0) return false;
  TickBudget(now);
  if (!OwnedPhysical(group) || group.GetPlayerCount(true) > 0 || m_Bodies.IsEmpty()) return false;
  ERR_HQBodyScan state;
  foreach (ERR_HQBodyScan scan : m_Groups) if (scan.Group == group) state = scan;
  if (!state) return false;
  state.LastAsked = now;
  if (now < state.NextScan || m_Traces <= 0 || OldestDue(now) != state) return false;
  state.NextScan = now + 15000;
  array<AIAgent> agents = {}; group.GetAgents(agents);
  int count = m_Bodies.Count();
  for (int visited = 0; visited < count; visited++)
  {
   if (state.Cursor >= count) state.Cursor = 0;
   ERR_HQBodyCandidate candidate = m_Bodies[state.Cursor++];
   if (!candidate.Corpse || candidate.Confirmed || now < candidate.ReportAfter || !Dead(candidate.Corpse)) continue;
   if (!candidate.Roster || !candidate.Roster.CanAttribute(candidate.Slot, candidate.Corpse)) continue;
   for (int member = 0; member < agents.Count() && member < 32; member++)
   {
    if (m_Traces <= 0) return false;
    AIAgent agent = agents[member];
    if (!agent) continue;
    vector position;
    if (!Visible(agent.GetControlledEntity(), candidate.Corpse, position)) continue;
    report = new ERR_HQReport();
    report.Target = candidate.Corpse; report.Source = group;
    report.Position = position; report.ObservedAt = now; report.TravelMode = "body";
    report.CasualtySourceId = candidate.SourceId; report.CasualtySlot = candidate.Slot;
    report.CasualtyStrength = candidate.Strength;
    // Local throttling only. A lost radio call can be retried after fresh LOS.
    candidate.ReportAfter = now + 15000;
    return true;
   }
  }
  return false;
 }
 // Call only after the radio-delivered immutable body attribution was accepted by HQ.
 void ConfirmDelivered(IEntity body)
 {
  if (!Replication.IsServer() || !body) return;
  foreach (ERR_HQBodyCandidate candidate : m_Roster)
   if (candidate.Corpse == body) candidate.Confirmed = true;
 }
 void Stop()
 {
  m_Roster.Clear(); m_Bodies.Clear(); m_Groups.Clear();
  m_Traces = 0; m_Now = -1; m_NextBudget = 0; m_RosterCursor = 0; m_CapLogged = false;
 }
}