GUI: add on-screen toasts and atomic config writes

- Toast queue drawn in the top-right by the overlay, independent of the GUI
  being open. Info/warn/error colors and 6/9/12 s lifetimes; timers start on
  the first painted frame so startup messages are not missed.
- Queue a load toast after install_menu, plus warnings/errors for missing
  modules/interfaces/netvars, input hooks, fonts, ISurface, server datamap,
  and spread seed support.
- Toast on config reload, reset, bind/unbind and config save failure.
- Config saves now write `config.tmp`, flush, then rename it over the real
  file; failures leave the previous config intact.
- config_load reports whether a file was found so Reload can distinguish a
  successful reload from a missing file.
- Update CONTEXT and ISURFACE_STATUS for the single GUI, toasts and atomic
  config writes.

1 files changed, 216 insertions, 1 deletions

diff --git a/src/gui.cpp b/src/gui.cpp
index 132068e..0d5b458 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -6,6 +6,7 @@
 #include "hl2h.h"
 
 #include <atomic>
+#include <cstdarg>
 #include <cmath>
 #include <cstdio>
 #include <cstdlib>
@@ -136,6 +137,7 @@ static void gui_init_sdl() {
   g_sdl_ready = sd_get_keys && sd_get_mouse;
   if (!g_sdl_ready) {
     logf("gui: SDL polling unavailable");
+    toastf(TOAST_ERROR, "GUI input unavailable: SDL not found");
     return;
   }
   if (sd_add_watch)
@@ -406,6 +408,56 @@ static float now_sec() {
   return (float)ts.tv_sec + (float)ts.tv_nsec * 1e-9f;
 }
 
+// ---------------------------------------------------------------------------
+// Toasts (shown even when the GUI is closed)
+// ---------------------------------------------------------------------------
+
+struct Toast {
+  char text[256];
+  int level;
+  double born; // 0 = waiting for the first draw
+  double ttl;
+};
+
+static Toast g_toasts[8];
+static int g_ntoasts = 0;
+static pthread_mutex_t g_toast_mu = PTHREAD_MUTEX_INITIALIZER;
+
+void toastf(int level, const char *fmt, ...) {
+  char buf[256];
+  va_list ap;
+  va_start(ap, fmt);
+  vsnprintf(buf, sizeof(buf), fmt, ap);
+  va_end(ap);
+
+  pthread_mutex_lock(&g_toast_mu);
+  for (int i = 0; i < g_ntoasts; i++) {
+    if (strcmp(g_toasts[i].text, buf) == 0) {
+      g_toasts[i].level = level;
+      g_toasts[i].born = 0.0;
+      pthread_mutex_unlock(&g_toast_mu);
+      return;
+    }
+  }
+  if (g_ntoasts == 8) {
+    memmove(&g_toasts[0], &g_toasts[1], sizeof(Toast) * 7);
+    g_ntoasts = 7;
+  }
+  Toast &t = g_toasts[g_ntoasts++];
+  snprintf(t.text, sizeof(t.text), "%s", buf);
+  t.level = level;
+  t.born = 0.0;
+  t.ttl = level == TOAST_ERROR ? 12.0 : level == TOAST_WARN ? 9.0 : 6.0;
+  pthread_mutex_unlock(&g_toast_mu);
+}
+
+bool gui_toasts_active() {
+  pthread_mutex_lock(&g_toast_mu);
+  bool active = g_ntoasts > 0;
+  pthread_mutex_unlock(&g_toast_mu);
+  return active;
+}
+
 static void ensure_fonts() {
   if (g_font_body && fabsf(g_font_scale - g_scale) < 0.001f)
     return;
@@ -437,8 +489,10 @@ static void ensure_fonts() {
   }
   if (!g_font_title)
     g_font_title = g_font_body;
-  if (!g_font_body)
+  if (!g_font_body) {
     logf("gui: no usable body font");
+    toastf(TOAST_ERROR, "No usable GUI font");
+  }
 }
 
 static int text_w(const char *s, int tall) {
@@ -698,6 +752,8 @@ static void handle_capture(const unsigned char *keys) {
     g_mouse_rclick = false;
     g_capture_card = -1;
     config_save();
+    toastf(TOAST_INFO, "%s bound to %s", card.title,
+           scancode_name(card.feat->bind));
     return;
   }
   for (int k = 0; k < 512; k++) {
@@ -709,6 +765,9 @@ static void handle_capture(const unsigned char *keys) {
       card.feat->bind = k;
     g_capture_card = -1;
     config_save();
+    if (card.feat)
+      toastf(TOAST_INFO, "%s bound to %s", card.title,
+             scancode_name(card.feat->bind));
     return;
   }
 }
@@ -795,6 +854,7 @@ static void handle_mouse_click() {
             if (mx >= bind.x + bind.w - S(18.0f)) {
               c.feat->bind = 0;
               config_save();
+              toastf(TOAST_INFO, "%s unbound (always-on)", c.title);
               return;
             }
             g_capture_card = i;
@@ -844,6 +904,7 @@ static void handle_mouse_click() {
                 config_reset_defaults();
                 g_reset_armed = false;
                 logf("gui: defaults restored");
+                toastf(TOAST_INFO, "Feature defaults restored");
               } else {
                 g_reset_armed = true;
                 g_reset_armed_at = now;
@@ -1198,6 +1259,160 @@ static void draw_tooltip() {
           inner.w, C_TEXT);
 }
 
+// ---------------------------------------------------------------------------
+// Toast drawing
+// ---------------------------------------------------------------------------
+
+static int wrap_toast(const char *text, int max_w, int tall,
+                      char lines[][256], int max_lines) {
+  int n = 0;
+  char cur[256] = {};
+  bool truncated = false;
+  const char *p = text;
+  while (*p) {
+    while (*p == ' ')
+      p++;
+    if (!*p)
+      break;
+    const char *start = p;
+    while (*p && *p != ' ')
+      p++;
+    size_t wl = (size_t)(p - start);
+    if (wl > 120)
+      wl = 120;
+    char word[128];
+    memcpy(word, start, wl);
+    word[wl] = 0;
+
+    char cand[256];
+    if (cur[0])
+      snprintf(cand, sizeof(cand), "%s %s", cur, word);
+    else
+      snprintf(cand, sizeof(cand), "%s", word);
+
+    if (text_w(cand, tall) <= max_w || !cur[0]) {
+      snprintf(cur, sizeof(cur), "%s", cand);
+      if (text_w(cur, tall) > max_w) {
+        // A single word longer than the panel: hard-truncate it.
+        int len = (int)strlen(cur);
+        while (len > 3 && text_w(cur, tall) > max_w)
+          cur[--len] = 0;
+        if (len > 3) {
+          cur[len - 3] = '.';
+          cur[len - 2] = '.';
+          cur[len - 1] = '.';
+        }
+        truncated = true;
+      }
+    } else {
+      if (n < max_lines)
+        snprintf(lines[n++], 256, "%s", cur);
+      else
+        truncated = true;
+      snprintf(cur, sizeof(cur), "%s", word);
+    }
+  }
+  if (cur[0]) {
+    if (n < max_lines)
+      snprintf(lines[n++], 256, "%s", cur);
+    else
+      truncated = true;
+  }
+  if (truncated && n > 0) {
+    char *last = lines[n - 1];
+    int len = (int)strlen(last);
+    if (len + 3 < 256) {
+      last[len++] = '.';
+      last[len++] = '.';
+      last[len++] = '.';
+      last[len] = 0;
+    }
+  }
+  return n;
+}
+
+void gui_draw_toasts() {
+  if (!g_surface)
+    return;
+  ensure_fonts();
+  if (!g_font_body || g_scr_w <= 0 || g_scr_h <= 0)
+    return;
+
+  Toast local[8];
+  int n = 0;
+  double now = now_sec();
+  pthread_mutex_lock(&g_toast_mu);
+  for (int i = 0; i < g_ntoasts; i++) {
+    Toast &t = g_toasts[i];
+    if (t.born == 0.0)
+      t.born = now;
+    if (now - t.born > t.ttl)
+      continue;
+    local[n++] = t;
+  }
+  g_ntoasts = 0;
+  for (int i = 0; i < n; i++)
+    g_toasts[g_ntoasts++] = local[i];
+  pthread_mutex_unlock(&g_toast_mu);
+
+  int margin = S(16.0f);
+  int max_w = S(420.0f);
+  if (max_w > g_scr_w - margin * 2)
+    max_w = g_scr_w - margin * 2;
+  int y = margin;
+  for (int i = 0; i < n; i++) {
+    const Toast &t = local[i];
+    float age = (float)(now - t.born);
+    float a = 1.0f;
+    if (age < 0.2f)
+      a = age / 0.2f;
+    else if (age > t.ttl - 0.5f)
+      a = (float)((t.ttl - age) / 0.5);
+    if (a < 0.0f) a = 0.0f;
+    if (a > 1.0f) a = 1.0f;
+    int alpha = (int)(a * 255.0f);
+
+    char lines[4][256];
+    int nl = wrap_toast(t.text, max_w, g_body_h, lines, 4);
+    if (nl == 0)
+      continue;
+    int line_w = 0;
+    for (int j = 0; j < nl; j++) {
+      int w = text_w(lines[j], g_body_h);
+      if (w > line_w)
+        line_w = w;
+    }
+    int pad = S(12.0f);
+    int line_h = g_body_h + S(4.0f);
+    int panel_w = line_w + pad * 2 + S(6.0f);
+    int panel_h = nl * line_h + pad * 2 - S(4.0f);
+    int x = g_scr_w - margin - panel_w;
+    if (x < margin)
+      x = margin;
+
+    Col accent = t.level == TOAST_ERROR
+                     ? Col{240, 90, 90, 255}
+                     : t.level == TOAST_WARN ? Col{255, 200, 80, 255}
+                                             : C_ACCENT;
+    fill(Rect{x, y, panel_w, panel_h}, Col{16, 18, 22, (int)(235 * a)});
+    outline(Rect{x, y, panel_w, panel_h}, Col{accent.r, accent.g, accent.b, alpha});
+    fill(Rect{x, y, S(4.0f), panel_h},
+         Col{accent.r, accent.g, accent.b, alpha});
+    s_text_font(g_font_body);
+    s_text_color(C_TEXT.r, C_TEXT.g, C_TEXT.b, alpha);
+    for (int j = 0; j < nl; j++) {
+      s_text_pos(x + pad + S(6.0f), y + pad + j * line_h);
+      wchar_t w[256];
+      size_t wn = mbstowcs(w, lines[j], 255);
+      if (wn == (size_t)-1)
+        continue;
+      w[wn] = 0;
+      s_print(w, (int)wn);
+    }
+    y += panel_h + S(8.0f);
+  }
+}
+
 void gui_draw() {
   if (!g_open || !g_surface)
     return;