AI: fix relationship lookup; classify citizen/hacked turrets

m_Relationship is DEFINE_UTLVECTOR (FIELD_CUSTOM), not FIELD_EMBEDDED, so the
datamap scan always returned -1 and every NPC fell back to the model
heuristic. Resolve it as FIELD_CUSTOM with an embedded fallback.

Floor turrets never add relationship rows when friendly: CNPC_FloorTurret
overrides Classify() to CLASS_PLAYER_ALLY for citizen-built
(SF_FLOOR_TURRET_CITIZEN) and Alyx-hacked turrets. Read m_spawnflags and
m_bHackedByAlyx from the server instead.

Widen the datamap offset window (0x4..0x4000) for derived-class fields and
log the new offsets plus turret state in the NPC debug line.

1 files changed, 51 insertions, 5 deletions

diff --git a/src/server.cpp b/src/server.cpp
index 4702c44..19be144 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -27,11 +27,18 @@ enum { EDICT_UNKNOWN_OFF = 0x0C };
 // fieldOffset[1]@0xC, fieldSize@0x10, flags@0x12, externalName@0x14
 enum {
   FIELD_INTEGER = 5,
+  FIELD_BOOLEAN = 6,
   FIELD_CHARACTER = 8,
   FIELD_EMBEDDED = 10,
+  FIELD_CUSTOM = 11,
   FIELD_EHANDLE = 13
 };
 
+// SF_FLOOR_TURRET_CITIZEN (npc_turret_floor.h). Citizen-built turrets
+// Classify() as CLASS_PLAYER_ALLY, i.e. they are friendly without ever adding
+// an entry to m_Relationship.
+static const int TURRET_FLAG_CITIZEN = 0x200;
+
 int g_srv_health = -1;
 int g_srv_maxhealth = -1;
 int g_srv_lifestate = -1;
@@ -41,6 +48,8 @@ int g_srv_velocity = -1;
 int g_srv_activeweapon = -1;
 static int g_srv_relationship = -1;
 static int g_srv_followtarget = -1;
+static int g_srv_spawnflags = -1;
+static int g_srv_hacked = -1;
 static bool g_srv_ready = false;
 static bool g_srv_checked = false;
 
@@ -58,7 +67,10 @@ static uintptr_t find_string(const char *s) {
 
 // Find the typedescription_t whose fieldName points at `name` and read its
 // fieldOffset. type filters false positives (m_iHealth is FIELD_INTEGER).
-static int datamap_offset(const char *name, int want_type) {
+// max_off is generous on purpose: derived-class fields (m_bHackedByAlyx,
+// m_hFollowTarget) live well past the base class size.
+static int datamap_offset(const char *name, int want_type, int min_off = 0x40,
+                          int max_off = 0x4000) {
   uintptr_t str = find_string(name);
   if (!str)
     return -1;
@@ -75,7 +87,7 @@ static int datamap_offset(const char *name, int want_type) {
       uintptr_t ext = *(const uintptr_t *)(e + 0x14);
       if (ftype != want_type)
         continue;
-      if (foff < 0x40 || foff > 0x2000)
+      if (foff < min_off || foff > max_off)
         continue;
       if (fsize < 1 || fsize > 64)
         continue;
@@ -118,16 +130,24 @@ bool resolve_server_netvars() {
   g_srv_absvelocity = datamap_offset("m_vecAbsVelocity", 3); // FIELD_VECTOR
   g_srv_velocity = datamap_offset("m_vecVelocity", 3);       // FIELD_VECTOR
   g_srv_activeweapon = datamap_offset("m_hActiveWeapon", FIELD_EHANDLE);
-  g_srv_relationship = datamap_offset("m_Relationship", FIELD_EMBEDDED);
+  // m_Relationship is DEFINE_UTLVECTOR, i.e. FIELD_CUSTOM (older builds used
+  // FIELD_EMBEDDED), never FIELD_EMBEDDED in the modern SDK.
+  g_srv_relationship = datamap_offset("m_Relationship", FIELD_CUSTOM);
+  if (g_srv_relationship < 0)
+    g_srv_relationship = datamap_offset("m_Relationship", FIELD_EMBEDDED);
   g_srv_followtarget = datamap_offset("m_hFollowTarget", FIELD_EHANDLE);
+  // CBaseEntity::m_spawnflags is a DEFINE_KEYFIELD at a low offset.
+  g_srv_spawnflags = datamap_offset("m_spawnflags", FIELD_INTEGER, 0x4);
+  g_srv_hacked = datamap_offset("m_bHackedByAlyx", FIELD_BOOLEAN);
   g_srv_ready = g_srv_health > 0;
   if (g_srv_ready) {
     logf("server datamap (%s): health=%d maxhealth=%d lifeste=%d "
          "modelindex=%d absvel=%d vel=%d activeweapon=%d relationship=%d "
-         "followtarget=%d",
+         "followtarget=%d spawnflags=%d hacked=%d",
          g_server.path.c_str(), g_srv_health, g_srv_maxhealth, g_srv_lifestate,
          g_srv_modelindex, g_srv_absvelocity, g_srv_velocity,
-         g_srv_activeweapon, g_srv_relationship, g_srv_followtarget);
+         g_srv_activeweapon, g_srv_relationship, g_srv_followtarget,
+         g_srv_spawnflags, g_srv_hacked);
     fail_logged = false;
   } else if (!fail_logged) {
     fail_logged = true;
@@ -245,6 +265,32 @@ bool server_npc_has_follow_target(int idx) {
   return h != 0 && h != 0xFFFFFFFFu;
 }
 
+// Turret friendliness that never appears in m_Relationship: CNPC_FloorTurret's
+// Classify() reports CLASS_PLAYER_ALLY for citizen-built (SF_FLOOR_TURRET_CITIZEN)
+// and Alyx-hacked turrets, which makes the default class table D_LI toward the
+// player. Returns -1 if unknown, else bit0 = citizen, bit1 = hacked.
+int server_npc_turret_flags(int idx) {
+  if (!g_srv_ready || (g_srv_spawnflags < 0 && g_srv_hacked < 0))
+    return -1;
+  void *base = nullptr;
+  server_entity_health(idx, nullptr, nullptr, &base);
+  if (!base)
+    return -1;
+  uintptr_t b = (uintptr_t)base;
+  int flags = -1;
+  int hacked = -1;
+  if (g_srv_spawnflags > 0)
+    flags = *(int *)(b + g_srv_spawnflags);
+  if (g_srv_hacked > 0)
+    hacked = (int)*(unsigned char *)(b + g_srv_hacked);
+  int out = 0;
+  if (flags > 0 && (flags & TURRET_FLAG_CITIZEN))
+    out |= 1;
+  if (hacked > 0)
+    out |= 2;
+  return out;
+}
+
 bool server_set_velocity_z(int idx, float vz) {
   if (!g_srv_ready || !g_iface.engineserver || g_srv_absvelocity <= 0)
     return false;