Jun 28 Optimize code

app/tenancy/middleware.py

@@ -7,6 +7,8 @@ Wires tenant resolution into the Flask request lifecycle.
   * always clears g.tenant / g.tenant_engine (so downstream code can rely on them)
   * does NOTHING further when MULTI_TENANT_ENABLED is False  → today's behaviour
   * bypasses static + configured exempt paths (health checks)
+  * MT-4: checks session['impersonating_tenant_id'] and short-circuits Host
+    resolution when a superadmin is impersonating a tenant
   * otherwise resolves the Host header to a tenant and selects its engine
   * returns a 404 page for an unknown / unverified / suspended host
 
@@ -15,7 +17,7 @@ so each request rebinds via RoutingSession.get_bind against the fresh
 g.tenant_engine — no teardown handler is needed here.
 """
 
-from flask import g, request, current_app, Response
+from flask import g, request, current_app, Response, session
 
 from app.tenancy.resolver import resolve_tenant
 from app.tenancy.engine_cache import get_tenant_engine
@@ -60,6 +62,43 @@ def init_tenancy(app):
         if _is_exempt(request.path):
             return
 
+        # ── MT-4: Superadmin impersonation override ───────────────────────
+        # When the control panel places a signed token in the session via
+        # /auth/impersonate, bypass Host resolution and bind directly to that
+        # tenant's DB. The session is server-signed so this is safe.
+        imp_id = session.get('impersonating_tenant_id')
+        if imp_id is not None:
+            from control.base import control_session
+            from control.models import Tenant
+            from app.tenancy.context import TenantContext
+            with control_session() as s:
+                t = s.get(Tenant, imp_id)
+                if t and t.status == 'active':
+                    plan = t.plan
+                    ctx = TenantContext(
+                        id=t.id,
+                        slug=t.slug,
+                        name=t.name,
+                        plan_id=t.plan_id,
+                        db_uri=t.db_uri,
+                        plan_code=plan.code if plan else None,
+                        max_users=plan.max_users if plan else None,
+                        max_facilities=plan.max_facilities if plan else None,
+                        max_inspections_month=plan.max_inspections_month if plan else None,
+                        max_issues_month=plan.max_issues_month if plan else None,
+                        allow_mobile_api=plan.allow_mobile_api if plan else True,
+                        allow_scheduled_reports=plan.allow_scheduled_reports if plan else True,
+                        allow_branding=plan.allow_branding if plan else True,
+                        allow_custom_domain=plan.allow_custom_domain if plan else True,
+                    )
+                    g.tenant = ctx
+                    g.tenant_engine = get_tenant_engine(ctx)
+                    return  # skip normal Host resolution
+            # Impersonation target invalid or suspended — clear and fall through
+            session.pop('impersonating_tenant_id', None)
+            session.pop('impersonating_superadmin_id', None)
+
+        # ── Normal Host → tenant resolution ──────────────────────────────
         host = (request.host or '').split(':')[0].strip().lower()
         tenant = resolve_tenant(host)
         if tenant is None: