Refactor networks quizzes, progress tracking, and page wiring.

Co-authored-by: Cursor <cursoragent@cursor.com>

progress.c

@@ -52,6 +52,7 @@ void unit_load_progress(UnitCtx *u) {
 void load_progress(void) {
     for (int i = 0; i < NUM_UNLOCKED; i++)
         unit_load_progress(&units[i]);
+    net_load_progress();
 }
 
 /* Redraw the exercise rails of every unit that already has a page. */
@@ -122,6 +123,7 @@ void refresh_completion_ui(void) {
     }
 
     all_rails_redraw();
+    refresh_net_completion_ui();
     refresh_stats_ui();
 }
 
@@ -132,3 +134,94 @@ void mark_done(UnitCtx *u, int n) {
     refresh_completion_ui();
     unit_save_progress(u);
 }
+
+void net_load_progress(void) {
+    GKeyFile *kf = g_key_file_new();
+    GError *err = NULL;
+
+    if (!g_key_file_load_from_file(kf, PROGRESS_NET, G_KEY_FILE_NONE, &err)) {
+        if (err)
+            g_error_free(err);
+        g_key_file_free(kf);
+        return;
+    }
+
+    for (int i = 0; i < NET_LESSONS; i++) {
+        gchar key[8];
+
+        g_snprintf(key, sizeof(key), "%d", i + 1);
+        net_lessons[i].done = g_key_file_get_boolean(kf, "done", key, NULL);
+    }
+
+    g_key_file_free(kf);
+}
+
+void net_save_progress(void) {
+    GKeyFile *kf = g_key_file_new();
+
+    for (int i = 0; i < NET_LESSONS; i++) {
+        gchar key[8];
+
+        g_snprintf(key, sizeof(key), "%d", i + 1);
+        g_key_file_set_boolean(kf, "done", key, net_lessons[i].done);
+    }
+
+    if (g_mkdir_with_parents(PROGRESS_DIR, 0755) != 0) {
+        g_key_file_free(kf);
+        return;
+    }
+
+    gchar *data = g_key_file_to_data(kf, NULL, NULL);
+    g_key_file_free(kf);
+
+    if (data) {
+        GError *err = NULL;
+        g_file_set_contents(PROGRESS_NET, data, -1, &err);
+        if (err)
+            g_error_free(err);
+        g_free(data);
+    }
+}
+
+void refresh_net_completion_ui(void) {
+    for (int i = 0; i < NET_LESSONS; i++) {
+        GtkWidget *node = net_nodes[i];
+        GtkWidget *icon = net_lessons[i].done_icon;
+
+        if (!node)
+            continue;
+        if (net_lessons[i].done) {
+            gtk_widget_remove_css_class(node, "current");
+            gtk_widget_add_css_class(node, "done");
+            if (icon)
+                gtk_widget_set_visible(icon, TRUE);
+        } else {
+            gtk_widget_remove_css_class(node, "done");
+            gtk_widget_add_css_class(node, "current");
+            if (icon)
+                gtk_widget_set_visible(icon, FALSE);
+        }
+    }
+}
+
+void mark_net_done(int lesson_id) {
+    if (lesson_id < 0 || lesson_id >= NET_LESSONS)
+        return;
+    if (net_lessons[lesson_id].done)
+        return;
+    net_lessons[lesson_id].done = TRUE;
+    net_save_progress();
+    refresh_net_completion_ui();
+    refresh_stats_ui();
+}
+
+void progress_for_net(ProgressSum *out) {
+    out->total_ex += NET_LESSONS;
+    out->open_units += NET_LESSONS;
+    for (int i = 0; i < NET_LESSONS; i++) {
+        if (net_lessons[i].done) {
+            out->done_ex++;
+            out->done_units++;
+        }
+    }
+}