feat(widget): add recurrence lookup endpoint (GET /api/widget/recurrence)

3 files changed, 78 insertions, 0 deletions

diff --git a/internal/handlers/timeline_logic_test.go b/internal/handlers/timeline_logic_test.go
index 9ddaeda..5e7cb27 100644
--- a/internal/handlers/timeline_logic_test.go
+++ b/internal/handlers/timeline_logic_test.go
@@ -23,6 +23,9 @@ type MockCalendarClient struct {
 	// with, for tests that need to assert on how the caller resolved its
 	// calendar ID list (e.g. fetchCalendarEvents' comma-split fallback).
 	SetCalendarIDsCalls [][]string
+	// RecurrenceRule is returned by GetRecurrenceRule for any id when RecurrenceErr is nil.
+	RecurrenceRule string
+	RecurrenceErr  error
 }
 
 func (m *MockCalendarClient) GetUpcomingEvents(ctx context.Context, maxResults int) ([]models.CalendarEvent, error) {
@@ -41,6 +44,10 @@ func (m *MockCalendarClient) SetCalendarIDs(ids []string) {
 	m.SetCalendarIDsCalls = append(m.SetCalendarIDsCalls, ids)
 }
 
+func (m *MockCalendarClient) GetRecurrenceRule(ctx context.Context, recurringEventID string) (string, error) {
+	return m.RecurrenceRule, m.RecurrenceErr
+}
+
 func setupTestStore(t *testing.T) *store.Store {
 	t.Helper()
 	tempDir := t.TempDir()
diff --git a/internal/handlers/widget.go b/internal/handlers/widget.go
index 29124fb..6b1e774 100644
--- a/internal/handlers/widget.go
+++ b/internal/handlers/widget.go
@@ -195,6 +195,28 @@ func (h *Handler) HandleWidgetComplete(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 }
 
+// HandleWidgetRecurrence looks up and formats a recurring calendar event's schedule.
+func (h *Handler) HandleWidgetRecurrence(w http.ResponseWriter, r *http.Request) {
+	recurringEventID := r.URL.Query().Get("recurring_event_id")
+	if recurringEventID == "" {
+		http.Error(w, "recurring_event_id is required", http.StatusBadRequest)
+		return
+	}
+
+	recurrence, err := h.googleCalendarClient.GetRecurrenceRule(r.Context(), recurringEventID)
+	if err != nil {
+		http.Error(w, "recurring event not found", http.StatusNotFound)
+		return
+	}
+
+	resp := struct {
+		Recurrence string `json:"recurrence"`
+	}{Recurrence: recurrence}
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(resp)
+}
+
 // HandleWidgetAdd creates a new undated native task from the widget's quick-add sheet.
 func (h *Handler) HandleWidgetAdd(w http.ResponseWriter, r *http.Request) {
 	var req widgetAddRequest
diff --git a/internal/handlers/widget_test.go b/internal/handlers/widget_test.go
index efe6858..610a55c 100644
--- a/internal/handlers/widget_test.go
+++ b/internal/handlers/widget_test.go
@@ -1,6 +1,8 @@
 package handlers
 
 import (
+	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -424,3 +426,50 @@ func TestTimelineItemToWidgetItem_NonRecurring_EmptyRecurringEventID(t *testing.
 		t.Errorf("expected empty RecurringEventID for a non-recurring event, got %q", wi.RecurringEventID)
 	}
 }
+
+// TestHandleWidgetRecurrence_ReturnsFormattedSchedule proves the recurrence
+// lookup endpoint: given a recurring_event_id query param, it calls the
+// calendar client's GetRecurrenceRule and returns the formatted text.
+func TestHandleWidgetRecurrence_ReturnsFormattedSchedule(t *testing.T) {
+	mock := &MockCalendarClient{RecurrenceRule: "Repeats weekly on Monday"}
+	h := &Handler{googleCalendarClient: mock}
+	req := httptest.NewRequest("GET", "/api/widget/recurrence?recurring_event_id=master-1", nil)
+	w := httptest.NewRecorder()
+	http.HandlerFunc(h.HandleWidgetRecurrence).ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	var resp struct {
+		Recurrence string `json:"recurrence"`
+	}
+	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+	if resp.Recurrence != "Repeats weekly on Monday" {
+		t.Errorf("recurrence = %q, want %q", resp.Recurrence, "Repeats weekly on Monday")
+	}
+}
+
+func TestHandleWidgetRecurrence_NotFound_Returns404(t *testing.T) {
+	mock := &MockCalendarClient{RecurrenceErr: fmt.Errorf("not found")}
+	h := &Handler{googleCalendarClient: mock}
+	req := httptest.NewRequest("GET", "/api/widget/recurrence?recurring_event_id=missing", nil)
+	w := httptest.NewRecorder()
+	http.HandlerFunc(h.HandleWidgetRecurrence).ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", w.Code)
+	}
+}
+
+func TestHandleWidgetRecurrence_MissingParam_Returns400(t *testing.T) {
+	h := &Handler{}
+	req := httptest.NewRequest("GET", "/api/widget/recurrence", nil)
+	w := httptest.NewRecorder()
+	http.HandlerFunc(h.HandleWidgetRecurrence).ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", w.Code)
+	}
+}