package status

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"testing"
	"time"

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

// listOnly hides the store's ModLister, as a store that cannot say when an
// object was written does.
type listOnly struct{ release.Store }

// refusesListMod has a ListMod that always refuses, as the claim's
// boundary stores answer when the store they wrap has none.
type refusesListMod struct{ release.Store }

func (refusesListMod) ListMod(context.Context, string) ([]release.KeyMod, error) {
	return nil, errors.New("required contract unavailable")
}

// T2 (region HA plan 2b): 250 reports of boxes a group replaced long ago
// do not hide the two boxes running now. The old reports are dropped from
// the listing before any read and before the key cap, and the reading is
// complete.
func TestStaleReportsDoNotHideLiveBoxes(t *testing.T) {
	ctx := context.Background()
	root := t.TempDir()
	s := release.NewDirStore(root)
	now := time.Now()
	put := func(label string, at time.Time) {
		raw, _ := json.Marshal(Box{Label: label, GeneratedAt: at})
		key := "status/boxes/" + label + ".json"
		if _, err := s.Put(ctx, key, raw, ""); err != nil {
			t.Fatal(err)
		}
		if err := os.Chtimes(filepath.Join(root, filepath.FromSlash(key)), at, at); err != nil {
			t.Fatal(err)
		}
	}
	for i := 0; i < 250; i++ {
		put(fmt.Sprintf("g-%020d", i), now.Add(-48*time.Hour))
	}
	put("g-live-one", now.Add(-time.Minute))
	put("g-live-two", now.Add(-2*time.Minute))
	// A report written an hour ago that says it is old: still listed (the
	// listing only drops what is plainly history) and judged stale by its
	// readers, as before.
	put("g-quiet", now.Add(-time.Hour))

	boxes, complete, err := LoadBoxesComplete(ctx, s)
	if err != nil || !complete {
		t.Fatalf("complete %v, err %v", complete, err)
	}
	var labels []string
	for _, b := range boxes {
		labels = append(labels, b.Label)
	}
	if fmt.Sprint(labels) != "[g-live-one g-live-two g-quiet]" {
		t.Fatalf("boxes %v", labels)
	}
	if !BoxStale(boxes[2], now, SnapshotPeriod) {
		t.Fatal("an old report read as fresh")
	}
	// A store with no write times is listed whole, as before: the cap
	// applies to all 253, and the reading says it is incomplete.
	if _, complete, err := LoadBoxesComplete(ctx, listOnly{s}); err != nil || complete {
		t.Fatalf("listed whole: complete %v, err %v", complete, err)
	}
	// A store whose ListMod refuses is listed whole too: the horizon is an
	// optimisation, so its failure never fails the read (the move door read
	// the fleet through the claim's boundary stores and answered 409 when
	// it did).
	if _, complete, err := LoadBoxesComplete(ctx, refusesListMod{s}); err != nil || complete {
		t.Fatalf("refused ListMod listed whole: complete %v, err %v", complete, err)
	}
}