Per-client ICS calendar feed, replacing the shared ICS_TOKEN (#22)

Each client now gets their own clients.ics_token (lazily generated on
first /owner/settings visit), which both authenticates and scopes
/api/bookings.ics -- closing the gap where any shared-token holder
could view another client's bookings by swapping the client_id query
param. The owner settings page now surfaces a copyable subscribe URL.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backoffice/app/app.py

@@ -38,9 +38,6 @@ app.register_blueprint(owner_settings_bp)
 app.secret_key = os.environ.get("SESSION_SECRET_KEY", "")
 
 CRM_TOKEN = os.environ.get("CRM_API_TOKEN", "")
-# Separate read-only token for the public iCal feed (calendar apps can't send
-# the basic-auth header, so the feed is gated by this query token instead).
-ICS_TOKEN = os.environ.get("ICS_TOKEN", "")
 
 # Static dashboard, with the CRM token injected so the (basic-auth-gated)
 # operator page can call the token-protected mutation endpoints.
@@ -256,21 +253,23 @@ def _ics_esc(t):
 
 @app.get("/api/bookings.ics")
 def bookings_ics():
-    """Read-only iCal feed for Apple/Google Calendar subscription. Gated by the
-    ICS_TOKEN query param (no header auth, so calendar apps can fetch it)."""
-    if not ICS_TOKEN or request.args.get("token") != ICS_TOKEN:
+    """Read-only iCal feed for Apple/Google Calendar subscription, scoped to
+    one client via their own clients.ics_token (#22). No header auth, since
+    calendar apps can't send one -- gated by the query token instead, but
+    unlike the old shared ICS_TOKEN + client_id pair, the token itself
+    resolves the client, so there's no separate client_id param that could
+    be swapped to view another tenant's bookings."""
+    client = bdb.get_client_by_ics_token(request.args.get("token"))
+    if client is None:
         return Response("forbidden\n", status=403, mimetype="text/plain")
-    cid = request.args.get("client_id")
+    cid = client["client_id"]
     with db.connect() as conn, conn.cursor() as cur:
-        if cid:
-            cur.execute("SELECT * FROM bookings WHERE client_id = %s ORDER BY start_time", (cid,))
-        else:
-            cur.execute("SELECT * FROM bookings ORDER BY start_time")
+        cur.execute("SELECT * FROM bookings WHERE client_id = %s ORDER BY start_time", (cid,))
         rows = cur.fetchall()
     now = datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")
     out = ["BEGIN:VCALENDAR", "VERSION:2.0", "PRODID:-//smb-crm//bookings//DE",
            "CALSCALE:GREGORIAN", "METHOD:PUBLISH",
-           "X-WR-CALNAME:" + _ics_esc("Buchungen " + cid if cid else "Buchungen")]
+           "X-WR-CALNAME:" + _ics_esc("Buchungen " + cid)]
     for r in rows:
         st = _ics_dt(r.get("start_time"))
         if not st:

backoffice/app/booking_db.py

@@ -340,6 +340,46 @@ def get_client_by_slug(slug):
         return cur.fetchone()
 
 
+def get_client_by_ics_token(token):
+    """Resolve a client for the per-client ICS feed (#22) -- like
+    get_client_by_slug, this is the one lookup that goes straight from
+    untrusted request input (the ?token= query param) to a client_id, so the
+    feed can be scoped to exactly one tenant without a separate client_id
+    param that could be swapped independently of the token."""
+    if not token:
+        return None
+    with db.connect() as conn, conn.cursor() as cur:
+        cur.execute("SELECT * FROM clients WHERE ics_token = %s", (token,))
+        return cur.fetchone()
+
+
+def ensure_ics_token(client_id):
+    """Return the client's ics_token, generating and persisting one on first
+    use (#22). Lazy rather than a one-off backfill migration, so clients
+    onboarded before this ticket still get a working subscribe URL the first
+    time their settings page loads. The UPDATE ... WHERE ics_token IS NULL
+    guard means a losing concurrent call re-reads the winner's token instead
+    of overwriting it -- same single-connection read-then-write shape as
+    consume_password_reset_token."""
+    with db.connect() as conn, conn.cursor() as cur:
+        cur.execute("SELECT ics_token FROM clients WHERE client_id = %s", (client_id,))
+        row = cur.fetchone()
+        if row is None:
+            return None
+        if row["ics_token"]:
+            return row["ics_token"]
+        cur.execute(
+            "UPDATE clients SET ics_token = %s WHERE client_id = %s AND ics_token IS NULL "
+            "RETURNING ics_token",
+            (secrets.token_urlsafe(24), client_id))
+        row = cur.fetchone()
+        if row is None:
+            cur.execute("SELECT ics_token FROM clients WHERE client_id = %s", (client_id,))
+            row = cur.fetchone()
+        conn.commit()
+        return row["ics_token"]
+
+
 _CLIENT_UPDATABLE = {"auto_confirm", "notify_channel"}
 
 

backoffice/app/owner_settings.py

@@ -61,9 +61,11 @@ def settings():
     hours_by_resource = {
         r["resource_id"]: bdb.get_resource_hours(client_id, r["resource_id"])
         for r in resources}
+    ics_token = bdb.ensure_ics_token(client_id)
     return render_template(
         "owner/settings.html", client=client, services=bdb.list_services(client_id),
         resources=resources, hours_by_resource=hours_by_resource, weekdays=WEEKDAYS,
+        ics_url=url_for("bookings_ics", token=ics_token, _external=True),
         error=request.args.get("error"))
 
 

backoffice/app/templates/owner/settings.html

@@ -155,6 +155,13 @@
     </form>
   </section>
 
+  <section>
+    <h2>Kalender-Abo</h2>
+    <p class="muted">Diese Adresse in Apple/Google Kalender als Abo hinzufügen, um Ihre eigenen
+      Termine automatisch angezeigt zu bekommen.</p>
+    <input type="text" value="{{ ics_url }}" readonly onclick="this.select()" style="width:100%;" />
+  </section>
+
   <p class="muted"><a href="{{ url_for('owner_auth.dashboard') }}">Zurück</a></p>
 </body>
 </html>

backoffice/app/tests/test_bookings_ics.py

@@ -0,0 +1,120 @@
+"""Flask test client / real-DB integration tests for the per-client ICS
+calendar feed (#22): each client's clients.ics_token gates and scopes
+/api/bookings.ics, replacing the old shared ICS_TOKEN + client_id query
+param. Same testing decision as #20/#21: assert on HTTP response + DB state.
+"""
+from datetime import datetime, timedelta, timezone
+
+import pytest
+
+import booking_db as bdb
+from app import app as flask_app
+
+CLIENT_A = "C-TEST-ICS-A"
+CLIENT_B = "C-TEST-ICS-B"
+
+
+@pytest.fixture
+def client():
+    flask_app.config["TESTING"] = True
+    flask_app.secret_key = "test-secret"
+    return flask_app.test_client()
+
+
+def _setup(client_id, business_name):
+    with bdb.db.connect() as conn, conn.cursor() as cur:
+        cur.execute(
+            "INSERT INTO clients (client_id, business_name, timezone, auto_confirm, ics_token) "
+            "VALUES (%s, %s, %s, %s, NULL) ON CONFLICT (client_id) DO UPDATE SET "
+            "business_name = EXCLUDED.business_name, ics_token = NULL",
+            (client_id, business_name, "Europe/Berlin", True))
+        conn.commit()
+    resource = bdb.create_resource(client_id, "Chair 1")
+    start = datetime.now(timezone.utc).replace(microsecond=0) + timedelta(days=1)
+    booking = bdb.create_booking(
+        client_id, resource["resource_id"], "Ivy", "ivy@example.com",
+        "Haircut", start, start + timedelta(minutes=30))
+    return resource, booking
+
+
+def _login(client, client_id, email="owner@example.com", password="correct horse"):
+    bdb.create_user(client_id, email, password)
+    client.post("/owner/login", data={"email": email, "password": password})
+
+
+# ---- token gating ----
+
+def test_missing_token_is_forbidden(client):
+    _setup(CLIENT_A, "Happy Nails")
+    resp = client.get("/api/bookings.ics")
+    assert resp.status_code == 403
+
+
+def test_bogus_token_is_forbidden(client):
+    _setup(CLIENT_A, "Happy Nails")
+    resp = client.get("/api/bookings.ics", query_string={"token": "not-a-real-token"})
+    assert resp.status_code == 403
+
+
+def test_valid_token_returns_only_that_clients_bookings(client):
+    _setup(CLIENT_A, "Happy Nails")
+    _setup(CLIENT_B, "Cafe Lichtblick")
+    token_a = bdb.ensure_ics_token(CLIENT_A)
+    resp = client.get("/api/bookings.ics", query_string={"token": token_a})
+    assert resp.status_code == 200
+    body = resp.get_data(as_text=True)
+    assert "Ivy" in body
+    assert CLIENT_A in body
+    assert CLIENT_B not in body
+
+
+def test_swapping_client_id_query_param_has_no_effect(client):
+    """The old feed let any token holder view another client's bookings by
+    changing client_id -- the new feed resolves the client from the token
+    alone, so a client_id param (even another tenant's) is simply ignored."""
+    _setup(CLIENT_A, "Happy Nails")
+    resource_b, booking_b = _setup(CLIENT_B, "Cafe Lichtblick")
+    token_a = bdb.ensure_ics_token(CLIENT_A)
+    resp = client.get("/api/bookings.ics", query_string={
+        "token": token_a, "client_id": CLIENT_B})
+    assert resp.status_code == 200
+    body = resp.get_data(as_text=True)
+    assert CLIENT_B not in body
+    assert CLIENT_A in body
+
+
+# ---- token provisioning ----
+
+def test_ensure_ics_token_generates_and_persists(client):
+    _setup(CLIENT_A, "Happy Nails")
+    assert bdb.get_client(CLIENT_A)["ics_token"] is None
+    token = bdb.ensure_ics_token(CLIENT_A)
+    assert token
+    assert bdb.get_client(CLIENT_A)["ics_token"] == token
+
+
+def test_ensure_ics_token_is_stable_across_calls(client):
+    _setup(CLIENT_A, "Happy Nails")
+    first = bdb.ensure_ics_token(CLIENT_A)
+    second = bdb.ensure_ics_token(CLIENT_A)
+    assert first == second
+
+
+def test_ensure_ics_token_differs_per_client(client):
+    _setup(CLIENT_A, "Happy Nails")
+    _setup(CLIENT_B, "Cafe Lichtblick")
+    assert bdb.ensure_ics_token(CLIENT_A) != bdb.ensure_ics_token(CLIENT_B)
+
+
+# ---- owner dashboard surfacing ----
+
+def test_settings_page_shows_subscribe_url_with_own_token(client):
+    _setup(CLIENT_A, "Happy Nails")
+    _login(client, CLIENT_A)
+    resp = client.get("/owner/settings")
+    assert resp.status_code == 200
+    body = resp.get_data(as_text=True)
+    token = bdb.get_client(CLIENT_A)["ics_token"]
+    assert token
+    assert f"token={token}" in body
+    assert "bookings.ics" in body