"""
app/tenancy/middleware.py
-------------------------
Wires tenant resolution into the Flask request lifecycle.
`init_tenancy(app)` registers a single app-level before_request handler that:
* 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
Flask-SQLAlchemy already removes the scoped session on app-context teardown,
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, session
from app.tenancy.resolver import resolve_tenant
from app.tenancy.engine_cache import get_tenant_engine
_UNKNOWN_TENANT_PAGE = (
"
"
""
"Workspace not found"
""
"
Workspace not found
"
"
This address isn’t linked to an active JQC workspace.
"
"
Check the URL, or contact your administrator.
"
"
"
)
def _is_exempt(path):
if path.startswith('/static/'):
return True
for prefix in current_app.config.get('MULTI_TENANT_EXEMPT_PATHS', []):
if prefix and path.startswith(prefix):
return True
return False
def init_tenancy(app):
@app.before_request
def _resolve_tenant():
# Default state — referenced safely by downstream code regardless of mode.
g.tenant = None
g.tenant_engine = None
if not current_app.config.get('MULTI_TENANT_ENABLED', False):
return # inert: default database serves everything (single-tenant)
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:
return Response(_UNKNOWN_TENANT_PAGE, status=404, mimetype='text/html')
g.tenant = tenant
g.tenant_engine = get_tenant_engine(tenant)