// Owned and ticked by HQ. Initial assets are authored once; losses are never replaced.
class ERR_MortarSystem
{
 protected ERR_HQ m_HQ;
 protected ref array<ref ERR_MortarBattery> m_Batteries = {};
 protected ref ERR_SettlementSafety m_Settlements = new ERR_SettlementSafety();
 protected bool m_Prepared;
 protected bool m_Stopped;
 protected float m_NextDecision;
 string SafetyReason;
 string SettlementReason;

 void ERR_MortarSystem(ERR_HQ hq) { m_HQ = hq; }
 static ERR_MortarSystem Get()
 {
  ERR_HQ hq = ERR_HQ.Get();
  if (!hq || !Replication.IsServer()) return null;
  return hq.Mortars();
 }
 static bool NearPlayer(vector position)
 {
  array<IEntity> players = {};
  ERR_Actors.Players(players);
  foreach (IEntity player : players)
   if (vector.DistanceXZ(player.GetOrigin(), position) <= 1200) return true;
  return false;
 }
 bool Prepare()
 {
  if (!Replication.IsServer() || m_Prepared || m_Stopped) return false;
  m_Prepared = true;
  vector position = ERR_Actors.Ground("6000 0 7000");
  if (position[1] < 1) return false;
  IEntity gun = ERR_Actors.Spawn(ERR_MortarBattery.GUN, position);
  SCR_AIGroup group = SCR_AIGroup.Cast(ERR_Actors.Spawn(MortarGroup(), ERR_Actors.Ground(position + "0 0 4")));
  if (!gun || !group)
  {
   ERR_Actors.DeleteSpawned(gun);
   ERR_Actors.DeleteSpawned(group);
   return false;
  }
  if (group.GetFaction() != ERR_GameMode.Get().EnemyFaction())
  {
   ERR_Actors.DeleteSpawned(gun);
   ERR_Actors.DeleteSpawned(group);
   return false;
  }
  FactionAffiliationComponent affiliation = FactionAffiliationComponent.Cast(gun.FindComponent(FactionAffiliationComponent));
  if (affiliation) affiliation.SetAffiliatedFaction(ERR_GameMode.Get().EnemyFaction());
  ERR_MortarBattery battery = new ERR_MortarBattery();
  battery.Bind(1, group, gun, GetGame().GetWorld().GetWorldTime());
  m_Batteries.Insert(battery);
  ERR_GameMode mode = ERR_GameMode.Get();
  mode.Own(gun);
  mode.RegisterGroup(group);
  m_HQ.ReserveGroup(group);
  battery.Audit("DEPLOY", "authored gun and four-person crew; finite ammunition initialization pending");
  return true;
 }
 static ResourceName MortarGroup() { return "{B84C05941C4C81B8}Prefabs/ERR/MortarCrew.et"; }
 ERR_MortarBattery FindGun(IEntity gun)
 {
  foreach (ERR_MortarBattery battery : m_Batteries)
   if (gun && battery.Gun == gun) return battery;
  return null;
 }
 ERR_MortarBattery FindGroup(SCR_AIGroup group)
 {
  foreach (ERR_MortarBattery battery : m_Batteries)
   if (group && battery.Group == group) return battery;
  return null;
 }
 ERR_HQReport Latest(ERR_MortarBattery battery, float now)
 {
  // Only the coordinates actually delivered to this battery are available.
  // A newer HQ contact cannot update a gun's knowledge without another downlink.
  if (!battery || !ERR_MortarPrediction.Fresh(battery.Report, now)) return null;
  return battery.Report;
 }
 string ContactFailure(ERR_MortarBattery battery)
 {
  if (!battery.Report) return "no delivered target report";
  return "delivered target report expired or invalid";
 }
 bool OutsideSettlements(vector impact)
 {
  bool clear = m_Settlements.OutsideSettlements(impact);
  SettlementReason = m_Settlements.SettlementReason;
  return clear;
 }
 bool Safe(ERR_MortarBattery battery, vector impact, float flight)
 {
  SafetyReason = "clear";
  if (!battery.Operational()) { SafetyReason = battery.OperationalReason(); return false; }
  if (!OutsideSettlements(impact)) { SafetyReason = SettlementReason; return false; }
  if (SCR_TerrainHelper.GetTerrainY(impact) < 0) { SafetyReason = "impact below Everon sea level"; return false; }
  Faction faction = battery.Group.GetFaction();
  if (!faction) { SafetyReason = "battery faction missing"; return false; }
  array<IEntity> friendlies = {};
  m_HQ.PhysicalForces(friendlies);
  foreach (IEntity entity : friendlies)
  {
   Faction friendly = SCR_FactionManager.SGetFaction(entity);
   if (!friendly || faction.IsFactionEnemy(friendly) || !ERR_Actors.Alive(entity)) continue;
   vector velocity;
   IEntity moving = CompartmentAccessComponent.GetVehicleIn(entity);
   if (!moving) moving = entity;
   if (moving.GetPhysics()) velocity = moving.GetPhysics().GetVelocity();
   if (ERR_MortarPrediction.ThreatensFriendly(impact, entity.GetOrigin(), velocity, flight))
   {
    SafetyReason = "friendly physical force can enter the impact area";
    return false;
   }
  }
  return true;
 }
 bool Withhold(ERR_MortarBattery battery, string reason, string detail = "")
 {
  battery.LastFailure = reason + "; " + detail;
  battery.Trace("WITHHELD", reason, detail);
  // Finish the activity from the next HQ tick, never from inside its own node.
  battery.Rejected = true;
  return false;
 }
 bool AllowShot(ERR_MortarBattery battery)
 {
  float now = GetGame().GetWorld().GetWorldTime();
  if (!ERR_HQ.MissionActive()) return Withhold(battery, "mission inactive");
  if (!battery.Operational()) return Withhold(battery, battery.OperationalReason());
  if (!battery.CommandOpen || battery.OrderShots >= ERR_MortarSalvo.ROUNDS) return Withhold(battery, "salvo complete or order closed");
  if (battery.Released) return Withhold(battery, "waiting for committed projectile");
  if (battery.AimedShot != battery.OrderShots || battery.AimedAt < 0 || now - battery.AimedAt > 10000) return Withhold(battery, "fresh aim solution required");
  ERR_HQReport report = Latest(battery, now);
  if (!report) return Withhold(battery, ContactFailure(battery));
  vector updated;
  if (!ERR_MortarPrediction.Predict(report, now, battery.FlightTime, updated)) return Withhold(battery, ERR_MortarPrediction.FailureReason);
  updated += battery.AimOffset;
  if (vector.DistanceXZ(updated, battery.Impact) > 60) return Withhold(battery, "predicted target left aimed impact area");
  if (!OutsideSettlements(updated)) return Withhold(battery, SettlementReason);
  if (!Safe(battery, battery.Impact, battery.FlightTime)) return Withhold(battery, SafetyReason);
  return true;
 }
 protected void AdvanceOrder(ERR_MortarBattery battery, float now)
 {
  if (!battery.RadioOrder) return;
  int state = battery.RadioOrder.Advance(now, m_HQ.Journal());
  if (state == 0) return;
  ERR_HQReport delivered = battery.PendingRadioReport;
  battery.RadioOrder = null;
  battery.PendingRadioReport = null;
  if (state < 0 || !ERR_MortarPrediction.Fresh(delivered, now) || !battery.Operational() || battery.Activity || !battery.SupplyGunner())
  {
   battery.Cancel("radio delivery, report freshness or gunner availability failed");
   battery.NextOrder = now + 10000;
   return;
  }
  battery.Order(delivered, now);
 }
 void Tick(float now)
 {
  if (m_Stopped || !Replication.IsServer()) return;
  foreach (ERR_MortarBattery battery : m_Batteries)
  {
   if (battery.Rejected && !battery.Released)
   {
    battery.Cancel("native aim or firing authorization rejected");
    battery.NextOrder = now + 10000;
   }
   battery.Rejected = false;
   battery.Update(now);
   AdvanceOrder(battery, now);
  }
  if (now < m_NextDecision) return;
  m_NextDecision = now + 10000;
  array<ref ERR_HQReport> reports = {};
  m_HQ.SupportContacts(reports, now);
  ERR_MortarBattery selected;
  ERR_HQReport target;
  float distance = float.MAX;
  foreach (ERR_MortarBattery battery : m_Batteries)
  {
   if (!battery.StartupActivated || !battery.Operational() || battery.Activity || battery.RadioOrder || now < battery.NextOrder || battery.CountShells() == 0) continue;
   foreach (ERR_HQReport report : reports)
   {
    float candidate = vector.DistanceXZ(battery.Position, report.Position);
    if (candidate < 350 || candidate > 4000 || candidate >= distance || !OutsideSettlements(report.Position)) continue;
    selected = battery;
    target = report;
    distance = candidate;
   }
  }
  if (!selected || !target) return;
  ERR_HQRoute route = m_HQ.Downlink(selected.Group, "MORTAR ORDER", target.Description(now), target.MessageId);
  if (!route) return;
  selected.BeginRequest(target, now);
  selected.RadioId = route.MessageId;
  selected.RadioOrder = route;
  selected.PendingRadioReport = target.Snapshot();
  m_NextDecision = now + 20000;
 }
 void AppendGuns(array<IEntity> entities)
 {
  foreach (ERR_MortarBattery battery : m_Batteries)
   if (battery.Gun && !entities.Contains(battery.Gun)) entities.Insert(battery.Gun);
 }
 string Status()
 {
  int ready, shells;
  foreach (ERR_MortarBattery battery : m_Batteries)
  {
   if (battery.StartupActivated && battery.Operational()) ready++;
   shells += battery.CountShells();
  }
  return string.Format("mortars %1/%2; HE shells %3", ready, m_Batteries.Count(), shells);
 }
 void Stop()
 {
  m_Stopped = true;
  foreach (ERR_MortarBattery battery : m_Batteries) battery.Cancel("HQ stopped");
 }
}