enum ERR_HQPursuitRole
{
 SEARCH,
 INTERCEPT,
 CONTAIN
}

// Pure decisions over delivered belief snapshots and HQ's own physical forces.
// No player/entity reads, spawning, timers, waypoints or independent assignments.
class ERR_HQPursuitRules
{
 static bool Finite(float value)
 {
  return value == value && value > -1e20 && value < 1e20;
 }
 static bool PositionValid(vector value)
 {
  return Finite(value[0]) && Finite(value[1]) && Finite(value[2]);
 }
 static int Limit(int configured) { return Math.Clamp(configured, 0, 3); }
 static bool Actionable(float confidence, float ageSeconds, float uncertainty)
 {
  return Finite(confidence) && Finite(ageSeconds) && Finite(uncertainty)
   && confidence >= 0.15 && confidence <= 1 && ageSeconds >= 0
   && uncertainty >= 0 && uncertainty <= 2000;
 }
 static bool Heading(vector velocity, bool reported)
 {
  if (!reported || !PositionValid(velocity)) return false;
  velocity[1] = 0;
  float speed = velocity.Length();
  return speed >= 0.5 && speed <= 70;
 }
 static ERR_HQPursuitRole Role(float confidence, float ageSeconds, float uncertainty,
  bool hasHeading, int slot)
 {
  // A stale/broad/weak track authorizes a search, never a precision interception.
  if (!Actionable(confidence, ageSeconds, uncertainty) || !hasHeading || slot < 0 || slot > 2)
   return ERR_HQPursuitRole.SEARCH;
  if (confidence < 0.65 || ageSeconds > 45 || uncertainty > 150) return ERR_HQPursuitRole.SEARCH;
  if (slot == 0) return ERR_HQPursuitRole.INTERCEPT;
  if (slot == 2 && confidence >= 0.8 && uncertainty <= 100) return ERR_HQPursuitRole.CONTAIN;
  return ERR_HQPursuitRole.SEARCH;
 }
 static float LifetimeSeconds(ERR_HQPursuitRole role)
 {
  if (role == ERR_HQPursuitRole.INTERCEPT) return 60;
  if (role == ERR_HQPursuitRole.CONTAIN) return 90;
  return 120;
 }
 static float TaskLifetimeSeconds(ERR_HQPursuitRole role, float distanceMetres)
 {
  if (!Finite(distanceMetres) || distanceMetres < 0) return 0;
  if (role != ERR_HQPursuitRole.SEARCH) return LifetimeSeconds(role);
  // Existing infantry must have time to travel and search. This is an absolute
  // order lifetime, not permission to refresh an old task indefinitely.
  return Math.Clamp(distanceMetres / 3 + 45, 120, 900);
 }
 static bool CanCommit(bool physical, bool eligible, bool busy, bool homeGuard,
  int homeAvailable, int assigned, int configured)
 {
  if (!physical || !eligible || busy || assigned < 0 || assigned >= Limit(configured)) return false;
  // Count only uncommitted physical home groups; pending radio orders spend one
  // immediately. Mobile patrols may leave; at least one home group must remain.
  return !homeGuard || homeAvailable > 1;
 }
 static int Bearing(vector forcePosition, vector beliefPosition)
 {
  if (!PositionValid(forcePosition) || !PositionValid(beliefPosition)) return -1;
  vector offset = forcePosition - beliefPosition;
  if (Math.AbsFloat(offset[0]) > Math.AbsFloat(offset[2]))
  {
   if (offset[0] >= 0) return 1;
   return 3;
  }
  if (offset[2] >= 0) return 0;
  return 2;
 }
 static bool BearingAllowed(int bearing, int first, int second)
 {
  if (bearing < 0 || bearing > 3 || first < -1 || first > 3 || second < -1 || second > 3)
   return false;
  if (first == -1 && second != -1) return false;
  // At most two occupied cardinal approach sectors; never close a full ring.
  return first == -1 || second == -1 || second == first || bearing == first || bearing == second;
 }
 static vector Direction(vector velocity, bool hasHeading)
 {
  if (!Heading(velocity, hasHeading)) return "0 0 1";
  velocity[1] = 0;
  return velocity.Normalized();
 }
 static vector Objective(vector position, vector velocity, bool hasHeading, float confidence,
  float ageSeconds, float uncertainty, ERR_HQPursuitRole role, int slot)
 {
  if (!PositionValid(position)) return "0 0 0";
  bool directionKnown = Heading(velocity, hasHeading);
  // Callers pass the memory's already predicted position. Do not extrapolate
  // report age a second time; the small future lead is independently bounded.
  ERR_HQPursuitRole permitted = Role(confidence, ageSeconds, uncertainty, directionKnown, slot);
  if (role != permitted) role = ERR_HQPursuitRole.SEARCH;
  vector forward = Direction(velocity, directionKnown);
  vector right = Vector(forward[2], 0, -forward[0]);
  float radius = 40;
  if (Finite(uncertainty)) radius = Math.Clamp(uncertainty, 40, 250);
  vector offset;
  if (role == ERR_HQPursuitRole.INTERCEPT)
  {
   velocity[1] = 0;
   float horizon = Math.Clamp(15 - ageSeconds * 0.2, 3, 15);
   float lead = Math.Clamp(velocity.Length() * horizon, 60, 200);
   offset = forward * lead;
  }
  else if (role == ERR_HQPursuitRole.CONTAIN)
   offset = forward * 80 + right * Math.Clamp(radius, 80, 150);
  else
  {
   // Distinct search sectors within the bounded uncertainty area. HQ/memory
   // owns sweep history; slot is a supplied sector, not an independent clock.
   int sector = slot % 4;
   if (sector < 0) sector += 4;
   if (sector == 0) offset = forward * radius;
   else if (sector == 1) offset = right * radius;
   else if (sector == 2) offset = right * -radius;
   else offset = forward * -radius;
  }
  if (offset.Length() > 300) offset = offset.Normalized() * 300;
  return position + offset;
 }
 // Lower scores win. A negative score rejects malformed geometry. Travel cost
 // dominates; direction penalties avoid ordering trailing units to overtake the
 // contact or sending a far-side guard across it to contain the other flank.
 static float Score(ERR_HQPursuitRole role, vector beliefPosition, vector velocity,
  vector forcePosition, vector objective)
 {
  if (!PositionValid(beliefPosition) || !PositionValid(forcePosition) || !PositionValid(objective))
   return -1;
  vector forward = Direction(velocity, true);
  vector offset = forcePosition - beliefPosition;
  offset[1] = 0;
  float cost = vector.DistanceXZ(forcePosition, objective);
  if (role != ERR_HQPursuitRole.SEARCH && cost > 3 * (LifetimeSeconds(role) - 10)) return -1;
  if (role == ERR_HQPursuitRole.INTERCEPT)
  {
   float ahead = vector.Dot(offset, forward);
   if (ahead < 0) cost += Math.Min(-ahead, 1000);
  }
  else if (role == ERR_HQPursuitRole.CONTAIN)
  {
   vector right = Vector(forward[2], 0, -forward[0]);
   float side = vector.Dot(offset, right);
   float intendedSide = vector.Dot(objective - beliefPosition, right);
   if (side * intendedSide < 0) cost += Math.Min(Math.AbsFloat(side), 1000);
  }
  return cost;
 }
 static bool Better(float score, int id, float bestScore, int bestId)
 {
  if (!Finite(score) || score < 0 || id <= 0) return false;
  if (bestId <= 0 || bestScore < 0) return true;
  if (score != bestScore) return score < bestScore;
  return id < bestId;
 }
}