Refine Engine bootstrap logging

Data/Engine/server.py

@@ -0,0 +1,51 @@
+"""Flask application factory for the Borealis Engine."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from flask import Flask
+from flask_cors import CORS
+from werkzeug.middleware.proxy_fix import ProxyFix
+
+from .config import EngineSettings
+
+
+def _resolve_static_folder(static_root: Path) -> tuple[str | None, str]:
+    if static_root.exists():
+        return str(static_root), "/"
+    return None, "/static"
+
+
+def create_app(settings: EngineSettings) -> Flask:
+    """Create the Flask application instance for the Engine."""
+
+    static_folder, static_url_path = _resolve_static_folder(settings.static_root)
+    app = Flask(
+        __name__,
+        static_folder=static_folder,
+        static_url_path=static_url_path,
+    )
+
+    app.config.update(
+        SECRET_KEY=settings.secret_key,
+        JSON_SORT_KEYS=False,
+        SESSION_COOKIE_HTTPONLY=True,
+        SESSION_COOKIE_SECURE=not settings.debug,
+        SESSION_COOKIE_SAMESITE="Lax",
+        ENGINE_DATABASE_PATH=str(settings.database_path),
+    )
+
+    # Respect upstream proxy headers when Borealis is hosted behind a TLS terminator.
+    app.wsgi_app = ProxyFix(app.wsgi_app, x_for=1, x_proto=1, x_host=1)  # type: ignore[assignment]
+
+    CORS(
+        app,
+        resources={r"/*": {"origins": list(settings.cors_allowed_origins)}},
+        supports_credentials=True,
+    )
+
+    return app
+
+
+__all__ = ["create_app"]