Fixed Engine Flask Server Accessibility

Data/Engine/services/WebUI/__init__.py

@@ -1,17 +1,86 @@
-"""WebUI service stubs for the Borealis Engine runtime.
-
-The future WebUI migration will centralise static asset serving, template
-rendering, and dev-server proxying here. Stage 1 keeps the placeholder so the
-application factory can stub out registration calls.
-"""
+"""WebUI static asset handling for the Borealis Engine runtime."""
 from __future__ import annotations
 
-from flask import Flask
+import logging
+from pathlib import Path
+from typing import Optional
+
+from flask import Blueprint, Flask, request, send_from_directory
+from werkzeug.exceptions import NotFound
 
 from ...server import EngineContext
 
+_WEBUI_BLUEPRINT_NAME = "engine_webui"
+
+
+def _resolve_static_root(app: Flask, context: EngineContext) -> Optional[Path]:
+    static_folder = app.static_folder
+    if not static_folder:
+        context.logger.error("Engine WebUI static folder is not configured.")
+        return None
+
+    static_path = Path(static_folder).resolve()
+    if not static_path.is_dir():
+        context.logger.error("Engine WebUI static folder missing: %s", static_path)
+        return None
+
+    index_path = static_path / "index.html"
+    if not index_path.is_file():
+        context.logger.error("Engine WebUI missing index.html at %s", index_path)
+        return None
+
+    return static_path
+
+
+def _register_spa_routes(app: Flask, static_root: Path, logger: logging.Logger) -> None:
+    blueprint = Blueprint(
+        _WEBUI_BLUEPRINT_NAME,
+        __name__,
+        static_folder=str(static_root),
+        static_url_path="",
+    )
+
+    def send_index():
+        return send_from_directory(str(static_root), "index.html")
+
+    @blueprint.route("/", defaults={"requested_path": ""})
+    @blueprint.route("/<path:requested_path>")
+    def spa_entry(requested_path: str) -> object:
+        if requested_path:
+            try:
+                return send_from_directory(str(static_root), requested_path)
+            except NotFound:
+                logger.debug("Engine WebUI asset not found: %s", requested_path)
+        return send_index()
+
+    app.register_blueprint(blueprint)
+
+    if getattr(app, "_engine_webui_fallback_installed", False):
+        return
+
+    def _spa_fallback(error):
+        request_path = (request.path or "").strip()
+        if request_path.startswith("/api") or request_path.startswith("/socket.io"):
+            return error
+        if "." in Path(request_path).name:
+            return error
+        if request.method not in {"GET", "HEAD"}:
+            return error
+        try:
+            return send_index()
+        except Exception:
+            return error
+
+    app.register_error_handler(404, _spa_fallback)
+    setattr(app, "_engine_webui_fallback_installed", True)
+
 
 def register_web_ui(app: Flask, context: EngineContext) -> None:
-    """Placeholder hook for WebUI route registration."""
+    """Register static asset routes for the Engine WebUI."""
 
-    context.logger.debug("Engine WebUI services are not yet implemented.")
+    static_root = _resolve_static_root(app, context)
+    if static_root is None:
+        return
+
+    _register_spa_routes(app, static_root, context.logger)
+    context.logger.info("Engine WebUI registered static assets from %s", static_root)