package settings

import (
	"io"
	"log"
	"os"
	"path/filepath"
	"testing"
)

// R-1199 reopened (2026-10-22): a household that unticks every mail must see an empty list after a restart — the hub
// mails by that empty list. Before: omitempty dropped the [] and the getter turned the missing list into the defaults.
// Both shapes: a fresh save, and the file Tester 1 and demo-hp actually hold (`{"cooldown_hours": 6}` only).
// RED-PROOF: with the getter's nil → DefaultEnabledEvents restored, both assertions fail — seen failing 2026-10-22.
func TestR1199Reopened_AnEmptySavedListStaysEmpty(t *testing.T) {
	p := filepath.Join(t.TempDir(), "s.json")
	s, _ := Load(p, log.New(io.Discard, "", 0))
	if err := s.SetNotificationPrefs(&NotificationPrefs{EnabledEvents: []string{}}); err != nil {
		t.Fatal(err)
	}
	s2, _ := Load(p, log.New(io.Discard, "", 0))
	if got := s2.GetNotificationPrefs().EnabledEvents; len(got) != 0 {
		t.Fatalf("a saved empty list came back as %v", got)
	}
	q := filepath.Join(t.TempDir(), "old.json")
	os.WriteFile(q, []byte(`{"notifications":{"cooldown_hours":6}}`), 0o600)
	s3, _ := Load(q, log.New(io.Discard, "", 0))
	if got := s3.GetNotificationPrefs().EnabledEvents; len(got) != 0 || !s3.NotificationPrefsSaved() {
		t.Fatalf("the live boxes' file shape reads as %v (saved=%t), want an empty saved list", got, s3.NotificationPrefsSaved())
	}
	// A box with nothing saved still shows the defaults.
	s4, _ := Load(filepath.Join(t.TempDir(), "n.json"), log.New(io.Discard, "", 0))
	if got := s4.GetNotificationPrefs().EnabledEvents; len(got) != len(DefaultEnabledEvents) {
		t.Fatalf("an unsaved box must show the defaults, got %d", len(got))
	}
}