Aug 5 - Add new design (switchable)

app/__init__.py

@@ -27,8 +27,40 @@ limiter       = Limiter(
 )
 
 
+# ── Design A/B test: per-request template overrides (phase48) ────────────────
+# A user on the 'modern' design gets templates/modern/<name>.html in place of
+# templates/<name>.html whenever that override exists; otherwise the normal
+# template is used and only the layout shell + CSS differ.
+#
+# The rewrite happens in get_template() (not in the loader) so Jinja's template
+# cache is keyed on the REWRITTEN name — a cached modern template can never be
+# served to a classic user, or vice versa.
+from flask.templating import Environment as _FlaskJinjaEnvironment
+
+
+class ThemedEnvironment(_FlaskJinjaEnvironment):
+    """Jinja environment that redirects template names to modern/<name>."""
+
+    # Populated once in create_app() by scanning templates/modern/.
+    jqc_modern_templates: set = set()
+
+    def get_template(self, name, parent=None, globals=None):
+        if (isinstance(name, str)
+                and self.jqc_modern_templates
+                and not name.startswith('modern/')):
+            candidate = 'modern/' + name
+            if candidate in self.jqc_modern_templates:
+                from flask import g, has_request_context
+                if has_request_context() and getattr(g, 'jqc_theme', 'classic') == 'modern':
+                    name = candidate
+        return super().get_template(name, parent, globals)
+
+
 def create_app(config_name='default'):
     app = Flask(__name__)
+    # Must be assigned BEFORE app.jinja_env is first touched (it is a cached
+    # property), so the themed subclass is the one actually instantiated.
+    app.jinja_environment = ThemedEnvironment
     app.config.from_object(config[config_name])
 
     # ── Reverse-proxy awareness (Nginx) ──────────────────────────────────────
@@ -111,6 +143,54 @@ def create_app(config_name='default'):
     from app.utils import storage as _storage
     app.jinja_env.globals['media_url'] = _storage.media_url
 
+    # ── Design A/B test wiring (phase48) ──────────────────────────────────
+    # Index the modern/ override templates once at boot, so get_template()
+    # never has to touch the filesystem per request.
+    _modern_root = os.path.join(app.template_folder or 'templates', 'modern')
+    if not os.path.isabs(_modern_root):
+        _modern_root = os.path.join(app.root_path, _modern_root)
+    _modern_set = set()
+    if os.path.isdir(_modern_root):
+        for _dirpath, _dirnames, _filenames in os.walk(_modern_root):
+            for _fn in _filenames:
+                if _fn.endswith('.html'):
+                    _rel = os.path.relpath(os.path.join(_dirpath, _fn), _modern_root)
+                    _modern_set.add('modern/' + _rel.replace(os.sep, '/'))
+    ThemedEnvironment.jqc_modern_templates = _modern_set
+    app.logger.info('UI themes | modern overrides indexed: %s', len(_modern_set))
+
+    from flask import g
+
+    @app.before_request
+    def resolve_ui_theme():
+        """Stash the active design on `g` for ThemedEnvironment.get_template()."""
+        # The mobile API renders no templates and authenticates by JWT — skip it
+        # so this never touches the Flask-Login session loader on API traffic.
+        if request.path.startswith('/api/'):
+            g.jqc_theme = 'classic'
+            return
+        from flask_login import current_user as _cu
+        theme = 'classic'
+        try:
+            if _cu.is_authenticated:
+                theme = _cu.ui_theme or 'classic'
+        except Exception:      # DB column missing (migration not yet run)
+            theme = 'classic'
+        g.jqc_theme = theme if theme in ('classic', 'modern') else 'classic'
+
+    @app.context_processor
+    def inject_ui_theme():
+        """Give base.html the shell to extend."""
+        from app.utils.time_utils import now_eastern
+        theme = getattr(g, 'jqc_theme', 'classic')
+        return {
+            'jqc_theme':  theme,
+            'jqc_layout': 'layouts/modern.html' if theme == 'modern'
+                          else 'layouts/classic.html',
+            # Long-form date shown in the modern dashboard header.
+            'now_display': now_eastern().strftime('%A, %B %-d, %Y'),
+        }
+
     # ── Inject unread notification count into every template context ──────
     # This powers the red badge on the navbar bell icon without requiring
     # individual routes to pass the count manually.
@@ -183,6 +263,7 @@ def create_app(config_name='default'):
     from app.routes import devices         # Admin device registry
     from app.routes import public          # Public facility QR pages (no login)
     from app.routes import scheduled_inspections  # Planned/recurring inspections
+    from app.routes import ui              # phase48 — design A/B test + new pages
 
     app.register_blueprint(auth.bp)
     app.register_blueprint(dashboard.bp)
@@ -201,6 +282,7 @@ def create_app(config_name='default'):
     app.register_blueprint(devices.bp)
     app.register_blueprint(public.bp)
     app.register_blueprint(scheduled_inspections.bp)
+    app.register_blueprint(ui.bp)
 
     # ── Mobile API (Phase 7 / Phase A / Phase B / Phase C) ───────────────────
     # The /api/v1 blueprint group uses JWT Bearer tokens — no CSRF cookies needed.