package mail

import (
	"context"
	"encoding/json"
	"errors"
	"os"
	"testing"
	"time"

	"github.com/carlosframework/platform/internal/release"
)

// The sweep is what finally removes email.json, a release after the
// migration stopped writing it. It is off by default and it never deletes a
// legacy record for an app that has not been migrated, because that record
// is still the only copy of that app's email.
func TestSweepLegacyRecordsOnlyRemovesMigratedApps(t *testing.T) {
	ctx := context.Background()
	s := release.NewDirStore(t.TempDir())
	now := time.Date(2026, 9, 15, 12, 0, 0, 0, time.UTC)
	seed := func(app string, migrated bool) {
		body, _ := json.Marshal(&Record{Schema: Schema, App: app,
			Declared: &Declared{EnvPrefix: "P", From: "noreply@x.com", At: now, By: "o@example.test"}})
		if _, err := s.Put(ctx, LegacyKey("bag", app), body, ""); err != nil {
			t.Fatal(err)
		}
		if migrated {
			if _, err := PutSender(ctx, s, "bag", app, &Sender{ID: SenderAppID, Scope: ScopeApp, Source: SourceDomain}, ""); err != nil {
				t.Fatal(err)
			}
		}
	}
	seed("migrated", true)
	seed("untouched", false)

	// Off by default: the flag is the whole guard, and a console that has
	// not been told to sweep sweeps nothing.
	if n, err := SweepLegacyRecords(ctx, s, false); n != 0 || err != nil {
		t.Fatalf("the sweep ran while disabled: %d %v", n, err)
	}
	if _, _, err := s.Get(ctx, LegacyKey("bag", "migrated")); err != nil {
		t.Fatalf("the disabled sweep deleted something: %v", err)
	}

	n, err := SweepLegacyRecords(ctx, s, true)
	if err != nil {
		t.Fatal(err)
	}
	if n != 1 {
		t.Fatalf("deleted %d, want 1", n)
	}
	if _, _, err := s.Get(ctx, LegacyKey("bag", "migrated")); !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("the migrated app's email.json survived: %v", err)
	}
	if _, _, err := s.Get(ctx, LegacyKey("bag", "untouched")); err != nil {
		t.Fatalf("an unmigrated app's only record was deleted: %v", err)
	}
	// Running it twice is a no-op, which is what makes it safe at every start.
	if n, err := SweepLegacyRecords(ctx, s, true); n != 0 || err != nil {
		t.Fatalf("a second sweep = %d %v, want 0 and no error", n, err)
	}
}