commands

app/template_logger.py

@@ -40,8 +40,19 @@ def log_info(message):
 
 
 def _write(level, message):
+    global _log_path
     if _log_path is None:
-        reset_log()
+        os.makedirs(LOGS_DIR, exist_ok=True)
+        _log_path = LOG_FILE
+        if not os.path.exists(_log_path):
+            # First-ever write with no prior reset_log() call in this
+            # process (e.g. a phase_N command run without a preceding
+            # clear_all): create the file fresh, but never truncate an
+            # existing log — separate process invocations of phase_1/2/3
+            # must all append to the same ongoing log.
+            with open(_log_path, "w", encoding="utf-8") as f:
+                f.write(f"Timetable generation log - started {datetime.datetime.now().isoformat()}\n")
+                f.write("=" * 80 + "\n")
     line = f"[{datetime.datetime.now().strftime('%H:%M:%S')}] {level}: {message}"
     with open(_log_path, "a", encoding="utf-8") as f:
         f.write(line + "\n")