feat: implement writable datastore directory resolution and update logging path in engine

Author: AsieduDevelopmentHub

engine/config.py

@@ -5,6 +5,9 @@
 Modules import from this file to ensure consistent behavior across the engine.
 """
 
+from __future__ import annotations
+
+import os
 from pathlib import Path
 
 # ---------------------------------------------------------------------------
@@ -14,8 +17,42 @@
 # Root directory of the app package
 APP_DIR = Path(__file__).parent
 
-# Persistent data storage directory
-DATASTORE_DIR = APP_DIR / "datastore"
+def _writable_datastore_dir() -> Path:
+    """
+    Resolve a writable datastore directory.
+
+    - Dev mode: using `engine/datastore/` is fine.
+    - Installed mode (e.g. under Program Files): we must not write into the install dir.
+
+    Order:
+    1) SENTRACORE_DATA_DIR (explicit override)
+    2) Local package datastore if it can be created/written
+    3) %LOCALAPPDATA%/SentraCore/datastore (Windows)
+    4) ~/.local/share/SentraCore/datastore (fallback)
+    """
+    override = os.environ.get("SENTRACORE_DATA_DIR")
+    if override:
+        return Path(override)
+
+    local = APP_DIR / "datastore"
+    try:
+        local.mkdir(parents=True, exist_ok=True)
+        test = local / ".write_test"
+        test.write_text("ok", encoding="utf-8")
+        test.unlink(missing_ok=True)
+        return local
+    except OSError:
+        pass
+
+    local_appdata = os.environ.get("LOCALAPPDATA")
+    if local_appdata:
+        return Path(local_appdata) / "SentraCore" / "datastore"
+
+    return Path.home() / ".local" / "share" / "SentraCore" / "datastore"
+
+
+# Persistent data storage directory (writable)
+DATASTORE_DIR = _writable_datastore_dir()
 
 # Baseline model persistence file
 BASELINE_FILE = DATASTORE_DIR / "baseline.json"

engine/main.py

@@ -31,7 +31,7 @@
 from engine.baseline.baseline_model import BaselineModel
 from engine.buffer.time_series_buffer import TimeSeriesBuffer
 from engine.collector.system_collector import SystemCollector
-from engine.config import API_HOST, API_PORT, COLLECTION_INTERVAL_SEC
+from engine.config import API_HOST, API_PORT, COLLECTION_INTERVAL_SEC, DATASTORE_DIR
 from engine.events.event_logger import EventLogger
 from engine.normalization.normalizer import NormalizedSnapshot, Normalizer
 from engine.process.process_tracker import ProcessImpact, ProcessTracker
@@ -273,16 +273,14 @@ def _configure_logging() -> None:
     """Configure structured logging for the engine."""
     # When packaged with PyInstaller + --noconsole, sys.stdout/sys.stderr can be None.
     # In that case, log to a file so the engine can still start and we can diagnose issues.
-    from pathlib import Path
-
     log_format = "%(asctime)s | %(levelname)-7s | %(name)s | %(message)s"
     datefmt = "%H:%M:%S"
 
     handlers: list[logging.Handler] = []
     if getattr(sys, "stdout", None) is not None:
         handlers.append(logging.StreamHandler(sys.stdout))
     else:
-        log_dir = Path(__file__).parent / "datastore" / "logs"
+        log_dir = DATASTORE_DIR / "logs"
         log_dir.mkdir(parents=True, exist_ok=True)
         handlers.append(logging.FileHandler(log_dir / "engine.log", encoding="utf-8"))