Logging: per-session file and debug-gated verbose logs

- Open /tmp/hl2hake.log once in the library constructor with "w" so each
  session starts clean, use line buffering, flush each line, and close it via
  atexit. No more fopen/fclose per message.
- Add logd() for verbose diagnostics, enabled only with HL2H_DEBUG=1.
- Move ESP/NPC scans, item-prop/item-classification logs, aimbot/silent-aim/
  melee/triggerbot/spread details, jumpbug tracking, bone dumps, netvar dumps,
  cmd-modified and ground-trace noise to logd().
- Keep logf() for lifecycle, config, warnings/errors, GUI open/close, item
  category/tagging summaries and item-crate detections so crate debugging
  works without the ESP stream.
- Supply crates now respect the max-distance slider (user change), with the
  stale comment and CONTEXT updated.
- Document HL2H_DEBUG=1 in play.sh and CONTEXT.

1 files changed, 56 insertions, 20 deletions

diff --git a/src/hl2h.cpp b/src/hl2h.cpp
index 8c6b5db..256b9ab 100644
--- a/src/hl2h.cpp
+++ b/src/hl2h.cpp
@@ -10,21 +10,56 @@
 // logging
 // ---------------------------------------------------------------------------
 
-void logf(const char *fmt, ...) {
-  va_list ap, ap2;
-  va_start(ap, fmt);
-  va_copy(ap2, ap);
-  fprintf(stderr, "hl2hake: ");
-  vfprintf(stderr, fmt, ap2);
-  fprintf(stderr, "\n");
+static FILE *g_log = nullptr;
+static bool g_log_debug = false;
+static pthread_mutex_t g_log_mu = PTHREAD_MUTEX_INITIALIZER;
+
+static void log_close() {
+  pthread_mutex_lock(&g_log_mu);
+  if (g_log) {
+    fclose(g_log);
+    g_log = nullptr;
+  }
+  pthread_mutex_unlock(&g_log_mu);
+}
+
+// Open once per process and truncate, so /tmp/hl2hake.log only ever contains
+// the current session. HL2H_DEBUG=1 enables logd() noise.
+static void log_open() {
+  const char *dbg = getenv("HL2H_DEBUG");
+  g_log_debug = dbg && *dbg && strcmp(dbg, "0") != 0;
+  g_log = fopen("/tmp/hl2hake.log", "w");
+  if (g_log)
+    setvbuf(g_log, nullptr, _IOLBF, 0);
+  atexit(log_close);
+}
+
+static void log_write(const char *fmt, va_list ap) {
+  char buf[4096];
+  vsnprintf(buf, sizeof(buf), fmt, ap);
+  pthread_mutex_lock(&g_log_mu);
+  fprintf(stderr, "hl2hake: %s\n", buf);
   fflush(stderr);
-  va_end(ap2);
-  if (FILE *f = fopen("/tmp/hl2hake.log", "a")) {
-    fprintf(f, "hl2hake: ");
-    vfprintf(f, fmt, ap);
-    fprintf(f, "\n");
-    fclose(f);
+  if (g_log) {
+    fprintf(g_log, "hl2hake: %s\n", buf);
+    fflush(g_log);
   }
+  pthread_mutex_unlock(&g_log_mu);
+}
+
+void logf(const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  log_write(fmt, ap);
+  va_end(ap);
+}
+
+void logd(const char *fmt, ...) {
+  if (!g_log_debug)
+    return;
+  va_list ap;
+  va_start(ap, fmt);
+  log_write(fmt, ap);
   va_end(ap);
 }
 
@@ -93,7 +128,7 @@ void note_modified(const CUserCmd *cmd, int flags, const float *vel) {
   fix_verified_crc(cmd->command_number, usercmd_checksum(cmd));
 
   if (g_modified_logged < 5) {
-    logf("cmd modified: seq=%d flags=0x%X buttons=0x%X fw=%.2f "
+    logd("cmd modified: seq=%d flags=0x%X buttons=0x%X fw=%.2f "
          "vel=(%.1f,%.1f,%.1f)",
          cmd->command_number, flags, cmd->buttons, cmd->forwardmove, vel[0],
          vel[1], vel[2]);
@@ -311,7 +346,7 @@ static bool jumpbug_apply(CUserCmd *cmd, int local, void *ent, int flags,
   }
   if (!jb_tracked) {
     jb_tracked = true;
-    logf("jumpbug: tracking x=%.1f vz=%.1f impact=%.1f", x, vz, impact);
+    logd("jumpbug: tracking x=%.1f vz=%.1f impact=%.1f", x, vz, impact);
   }
 
   bool assist = jumpbug_assist_enabled();
@@ -345,7 +380,7 @@ static bool jumpbug_apply(CUserCmd *cmd, int local, void *ent, int flags,
       jb_tracked = false;
       if (jb_logs < 30) {
         jb_logs++;
-        logf("jumpbug: trigger x=%.2f drop=%.2f vz=%.1f assist=%d", x, jb_drop,
+        logd("jumpbug: trigger x=%.2f drop=%.2f vz=%.1f assist=%d", x, jb_drop,
              vz, (int)assist);
       }
     } else {
@@ -357,7 +392,7 @@ static bool jumpbug_apply(CUserCmd *cmd, int local, void *ent, int flags,
           if (jb_force_next_distance(local, ent, vel, x, JB_TARGET_DIST)) {
             if (jb_logs < 30) {
               jb_logs++;
-              logf("jumpbug: assist duck x=%.2f next=%.2f -> vz=%.1f", x,
+              logd("jumpbug: assist duck x=%.2f next=%.2f -> vz=%.1f", x,
                    next_x, vel[2]);
             }
           } else {
@@ -391,10 +426,10 @@ static bool jumpbug_apply(CUserCmd *cmd, int local, void *ent, int flags,
       if (jb_logs < 30) {
         jb_logs++;
         if (assist)
-          logf("jumpbug: setup assist x=%.2f drop=%.2f vz=%.1f ok=%d", x,
+          logd("jumpbug: setup assist x=%.2f drop=%.2f vz=%.1f ok=%d", x,
                jb_drop, vel[2], (int)forced);
         else
-          logf("jumpbug: setup x=%.2f drop=%.2f pred=%.2f vz=%.1f", x,
+          logd("jumpbug: setup x=%.2f drop=%.2f pred=%.2f vz=%.1f", x,
                jb_drop, x + JB_DUCK_RAISE - jb_drop, vz);
       }
     }
@@ -458,7 +493,7 @@ static void hkdSrvRandomSeed(int seed) {
   if (trace && (bullet_site || logs < 12)) {
     if (logs < 200) {
       logs++;
-      logf("srvseed: seed=%d off=0x%lx bullet=%d self=%p local=%d", seed, off,
+      logd("srvseed: seed=%d off=0x%lx bullet=%d self=%p local=%d", seed, off,
            (int)bullet_site, self, (int)local);
     }
   }
@@ -893,6 +928,7 @@ static void *setup_thread(void *) {
 __attribute__((constructor)) static void hl2hake_load() {
   if (!is_hl2_process())
     return;
+  log_open();
   logf("loaded (pid %d) build %s %s", getpid(), __DATE__, __TIME__);
   pthread_t t;
   if (pthread_create(&t, nullptr, setup_thread, nullptr) == 0)