G2.1: save full instrument state to disk (path/type/preset/transport)

native_bridge/src/StateStore.cpp

@@ -6,6 +6,8 @@
 #include <cstring>
 #include <fstream>
 #include <sstream>
+#include <cerrno>
+#include <sys/stat.h>
 
 #ifdef _WIN32
 #include <windows.h>
@@ -37,6 +39,30 @@ std::string jsonEscape(const std::string& s) {
     return out;
 }
 
+// Create the parent directory of `path` (all missing levels). Returns false
+// only on a hard error (permission, invalid path).
+bool ensureParentDir(const std::string& path) {
+    const size_t slash = path.find_last_of("/\\");
+    if (slash == std::string::npos) return true;
+    const std::string dir = path.substr(0, slash);
+    if (dir.empty()) return true;
+#ifdef _WIN32
+    // CreateDirectoryA creates one level at a time - walk the chain so
+    // %APPDATA%\SonicForgeDAW\state (or a custom SF_STATE_FILE dir) is
+    // created even when none of it exists yet.
+    for (size_t i = 0; i < dir.size(); ++i) {
+        if ((dir[i] == '/' || dir[i] == '\\') && i > 0)
+            CreateDirectoryA(dir.substr(0, i).c_str(), nullptr);
+    }
+    if (CreateDirectoryA(dir.c_str(), nullptr)) return true;
+    return GetLastError() == ERROR_ALREADY_EXISTS;
+#else
+    for (size_t i = 1; i < dir.size(); ++i)
+        if (dir[i] == '/') mkdir(dir.substr(0, i).c_str(), 0755);
+    return mkdir(dir.c_str(), 0755) == 0 || errno == EEXIST;
+#endif
+}
+
 // Skip whitespace; returns pointer at first non-ws char.
 const char* skipWs(const char* p) {
     while (p && *p && (*p == ' ' || *p == '\t' || *p == '\n' || *p == '\r')) ++p;
@@ -144,6 +170,7 @@ std::string StateStore::defaultPath() {
 }
 
 bool StateStore::save(const BridgeStateSnapshot& snap, const std::string& path) {
+    if (!ensureParentDir(path)) return false;
     std::string json;
     json.reserve(256 + snap.instruments.size() * 192);
     json += "{\n";