2 files changed, 34 insertions, 0 deletions
diff --git a/internal/handlers/widget.go b/internal/handlers/widget.go
index 876aaad..6c3b455 100644
--- a/internal/handlers/widget.go
+++ b/internal/handlers/widget.go
@@ -2,12 +2,14 @@ package handlers
 
 import (
 	"encoding/json"
+	"errors"
 	"net/http"
 	"strings"
 	"time"
 
 	"task-dashboard/internal/config"
 	"task-dashboard/internal/models"
+	"task-dashboard/internal/store"
 )
 
 // WidgetAuthMiddleware validates the static bearer token for widget API endpoints.
@@ -126,6 +128,10 @@ func (h *Handler) HandleWidgetReschedule(w http.ResponseWriter, r *http.Request)
 	tz := config.GetDisplayTimezone()
 	dueDate := time.Date(parsed.Year(), parsed.Month(), parsed.Day(), 0, 0, 0, 0, tz)
 	if err := h.store.RescheduleNativeTask(req.ID, dueDate); err != nil {
+		if errors.Is(err, store.ErrNativeTaskNotFound) {
+			http.Error(w, "task not found", http.StatusNotFound)
+			return
+		}
 		http.Error(w, "failed to reschedule", http.StatusInternalServerError)
 		return
 	}
@@ -143,6 +149,14 @@ func (h *Handler) HandleWidgetComplete(w http.ResponseWriter, r *http.Request) {
 	switch req.Source {
 	case "doot":
 		if err := h.store.CompleteNativeTask(req.ID); err != nil {
+			if errors.Is(err, store.ErrNativeTaskNotFound) {
+				// Surfaced as 404 (not a silent 200) so the caller -- the
+				// Android widget -- can tell "nothing changed" apart from
+				// "it worked", instead of the previous behavior where a
+				// stale/wrong id looked identical to a real completion.
+				http.Error(w, "task not found", http.StatusNotFound)
+				return
+			}
 			http.Error(w, "failed to complete task", http.StatusInternalServerError)
 			return
 		}
diff --git a/internal/handlers/widget_test.go b/internal/handlers/widget_test.go
index f56fe07..850dc07 100644
--- a/internal/handlers/widget_test.go
+++ b/internal/handlers/widget_test.go
@@ -121,6 +121,26 @@ func TestHandleWidgetComplete_NonCompletable(t *testing.T) {
 	}
 }
 
+// TestHandleWidgetComplete_UnknownID_Returns404 proves the 2026-07-12 fix at
+// the handler layer: a "doot" completion for an id that doesn't exist must
+// surface as 404, not the previous silent 200 (see
+// store.ErrNativeTaskNotFound's doc comment for the underlying bug this
+// closes -- a real production incident where the widget's completeTask tap
+// intermittently looked like it worked but changed nothing).
+func TestHandleWidgetComplete_UnknownID_Returns404(t *testing.T) {
+	s, cleanup := setupTestDB(t)
+	defer cleanup()
+	h := &Handler{store: s}
+	body := `{"id":"does-not-exist","source":"doot"}`
+	req := httptest.NewRequest("POST", "/api/widget/complete", strings.NewReader(body))
+	w := httptest.NewRecorder()
+	http.HandlerFunc(h.HandleWidgetComplete).ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", w.Code)
+	}
+}
+
 func TestWidgetAuthMiddleware_EmptyToken(t *testing.T) {
 	inner := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {})
 	h := WidgetAuthMiddleware("", inner)