package release

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"os"
	"strings"
	"testing"

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

// erroringStore is a Store whose every operation fails with a NON-not-found
// error — the "bucket on fire" case a read must never swallow.
type erroringStore struct{ err error }

func (e *erroringStore) Get(context.Context, string) ([]byte, string, error) {
	return nil, "", e.err
}
func (e *erroringStore) Put(context.Context, string, []byte, string) (string, error) {
	return "", e.err
}
func (e *erroringStore) List(context.Context, string) ([]string, error)     { return nil, e.err }
func (e *erroringStore) ListDirs(context.Context, string) ([]string, error) { return nil, e.err }
func (e *erroringStore) Delete(context.Context, string) error               { return e.err }

// legacyTripwire fails the test if anything asks the store for a key or
// prefix under one app's LEGACY unqualified prefix. It is how "the runtime
// does not read legacy keys" is pinned as a property rather than asserted one
// call site at a time: a fallback that crept back into any read path would
// trip it, whatever shape it took.
type legacyTripwire struct {
	Store
	t   *testing.T
	app string
}

func (l *legacyTripwire) tripped(what, key string) {
	l.t.Helper()
	if strings.HasPrefix(key, LegacyAppPrefix(l.app)) {
		l.t.Errorf("the runtime %s a legacy key: %s — the read-fallback is retired", what, key)
	}
}

func (l *legacyTripwire) Get(ctx context.Context, key string) ([]byte, string, error) {
	l.tripped("read", key)
	return l.Store.Get(ctx, key)
}

// Open is tripped too: staging streams the artifact (#269), and without this
// a streamed read would reach the store under the tripwire unwatched.
func (l *legacyTripwire) Open(ctx context.Context, key string) (io.ReadCloser, string, error) {
	l.tripped("read", key)
	return OpenObject(ctx, l.Store, key)
}

func (l *legacyTripwire) List(ctx context.Context, prefix string) ([]string, error) {
	l.tripped("listed", prefix)
	return l.Store.List(ctx, prefix)
}

func TestKeysAreAccountScoped(t *testing.T) {
	if got := ChannelKey("kqmv", "kass", "stable"); got != "apps/kqmv/kass/channels/stable.json" {
		t.Errorf("ChannelKey = %q", got)
	}
	if got := ManifestKey("bab", "console", "abc1234"); got != "apps/bab/console/releases/abc1234/manifest.json" {
		t.Errorf("ManifestKey = %q", got)
	}
	if got := ArtifactKey("kqmv", "kass", "v1", "kass"); got != "apps/kqmv/kass/releases/v1/kass" {
		t.Errorf("ArtifactKey = %q", got)
	}
	// The legacy shapes stay reachable BY NAME — no read path resolves
	// through them any more, but `accounts migrate -from legacy` still has to
	// be able to spell them, forever.
	if got := LegacyChannelKey("kass", "stable"); got != "apps/kass/channels/stable.json" {
		t.Errorf("LegacyChannelKey = %q", got)
	}
	if got := LegacyManifestKey("console", "abc1234"); got != "apps/console/releases/abc1234/manifest.json" {
		t.Errorf("LegacyManifestKey = %q", got)
	}
	if got := LegacyArtifactKey("kass", "v1", "kass"); got != "apps/kass/releases/v1/kass" {
		t.Errorf("LegacyArtifactKey = %q", got)
	}
}

// An empty account must never silently rebuild a legacy key: that would make
// an unqualified write look like a successful qualified one, and the
// migration would then never notice the app had not moved.
func TestEmptyAccountDoesNotRebuildALegacyKey(t *testing.T) {
	if got := ChannelKey("", "kass", "stable"); got == LegacyChannelKey("kass", "stable") {
		t.Errorf("ChannelKey(\"\", ...) = %q — an empty account rebuilt the legacy key", got)
	}
}

// The retirement, at its smallest: a legacy object at the matching
// unqualified key does not answer a qualified read. It used to.
func TestGetQualifiedDoesNotFallBack(t *testing.T) {
	s := NewDirStore(t.TempDir())
	ctx := context.Background()
	if _, err := s.Put(ctx, "apps/kass/channels/stable.json", []byte("legacy"), ""); err != nil {
		t.Fatal(err)
	}
	if _, _, err := GetQualified(ctx, s, "apps/kqmv/kass/channels/stable.json"); !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("a legacy object answered a qualified read: err = %v", err)
	}
	if _, err := s.Put(ctx, "apps/kqmv/kass/channels/stable.json", []byte("qualified"), ""); err != nil {
		t.Fatal(err)
	}
	body, _, err := GetQualified(ctx, s, "apps/kqmv/kass/channels/stable.json")
	if err != nil || string(body) != "qualified" {
		t.Fatalf("qualified read: body=%q err=%v", body, err)
	}
}

// A miss is actionable: a deployment that upgraded from a pre-accounts binary
// without migrating gets the exact command, not a mystery 404. It is still
// os.ErrNotExist-wrapped, so every caller's "has this app ever shipped here"
// check keeps working.
func TestQualifiedMissNamesTheMigrationCommand(t *testing.T) {
	s := NewDirStore(t.TempDir())
	_, _, err := GetQualified(context.Background(), s, ChannelKey("kqmv", "kass", "stable"))
	if !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("miss = %v, want os.ErrNotExist-wrapped", err)
	}
	if !strings.Contains(err.Error(), "carlos accounts migrate --app kass --from legacy --to kqmv") {
		t.Errorf("miss does not name the fix:\n%s", err)
	}
}

// The hint is only for app keys. A miss on anything else (status snapshots,
// account manifests) must not advertise a command that cannot apply to it.
func TestNonAppKeyMissCarriesNoMigrationHint(t *testing.T) {
	s := NewDirStore(t.TempDir())
	_, _, err := GetQualified(context.Background(), s, "status/fleet.json")
	if !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("miss = %v, want os.ErrNotExist-wrapped", err)
	}
	if strings.Contains(err.Error(), "accounts migrate") {
		t.Errorf("status/fleet.json miss suggested a migration:\n%s", err)
	}
}

// A store error that is NOT not-found must surface untouched, and must never
// acquire a migration hint: telling an operator to migrate because the bucket
// is unreachable sends them at the wrong problem.
func TestGetQualifiedPropagatesRealErrors(t *testing.T) {
	s := &erroringStore{err: errors.New("bucket on fire")}
	_, _, err := GetQualified(context.Background(), s, ChannelKey("kqmv", "kass", "stable"))
	if err == nil || !strings.Contains(err.Error(), "on fire") {
		t.Fatalf("want the real error, got %v", err)
	}
	if strings.Contains(err.Error(), "accounts migrate") {
		t.Errorf("a broken bucket was reported as an unmigrated app:\n%s", err)
	}
}

// THE test the retirement exists for: an app whose objects are ONLY at the
// legacy keys is invisible to every runtime read path. Nothing resolves it,
// nothing lists it, and — the tripwire — nothing so much as touches its
// legacy prefix on the way to finding that out.
//
// Adopt SKIPS such an app rather than failing the pass: one app's missing
// pointer must not stop every other app on the box from installing, which is
// already how a channel with nothing promoted behaves. The loudness lives in
// the error text (asserted here), which adopt prints per channel.
func TestLegacyOnlyAppIsInvisibleToTheRuntime(t *testing.T) {
	dir := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, pub := testKeys(t)
	s := &legacyTripwire{Store: dir, t: t, app: "old"}

	// A wholly legacy app: manifest, artifact and pointer all unqualified.
	m := Manifest{Schema: 1, App: "old", Version: "v1", Kind: "binary",
		Artifacts: map[string]Artifact{"linux-amd64": {File: "old", SHA256: etagOf([]byte("bin")), Size: 3}}}
	raw, err := json.MarshalIndent(m, "", "  ")
	if err != nil {
		t.Fatal(err)
	}
	if _, err := dir.Put(ctx, LegacyArtifactKey("old", "v1", "old"), []byte("bin"), ""); err != nil {
		t.Fatal(err)
	}
	if _, err := dir.Put(ctx, LegacyManifestKey("old", "v1"), raw, ""); err != nil {
		t.Fatal(err)
	}
	ptr, err := signPointer(RootSigner(priv), &ChannelPointer{Account: "bab", App: "old", Channel: "stable", Version: "v1"})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := dir.Put(ctx, LegacyChannelKey("old", "stable"), ptr, ""); err != nil {
		t.Fatal(err)
	}

	if _, err := GetManifest(ctx, s, OpsAccount, "old", "v1"); !errors.Is(err, os.ErrNotExist) {
		t.Errorf("GetManifest resolved a legacy-only app: %v", err)
	} else if !strings.Contains(err.Error(), "--from legacy") {
		t.Errorf("GetManifest miss is not actionable:\n%s", err)
	}
	if _, err := Channel(ctx, s, pub, OpsAccount, "old", "stable"); !errors.Is(err, os.ErrNotExist) {
		t.Errorf("Channel resolved a legacy-only app: %v", err)
	} else if !strings.Contains(err.Error(), "carlos accounts migrate --app old --from legacy --to bab") {
		t.Errorf("Channel miss is not actionable:\n%s", err)
	}
	// Listing paths see nothing either, so the console and `carlos channels`
	// show an empty app rather than a row they cannot resolve.
	keys, err := s.List(ctx, ChannelsPrefix(OpsAccount, "old"))
	if err != nil || len(keys) != 0 {
		t.Errorf("channels listing = %v (err %v), want empty", keys, err)
	}
	rung, err := VersionRung(ctx, s, pub, OpsAccount, "old", "v1")
	if err != nil || rung != "" {
		t.Errorf("VersionRung = %q (err %v), want no rung", rung, err)
	}
}

// A tripwire only guards the paths a test routes through it, so the ARTIFACT
// download — the read that puts bytes on a box — gets its own pass. Its
// fixture is the half-migrated shape that makes the read observable: pointer
// and manifest qualified (so the pass gets as far as staging), the artifact
// itself only at the legacy key. A fallback reintroduced in ensureStaged
// would find those bytes and stage them; qualified-only cannot, so the host
// is left alone and the pass survives.
//
// Without this, a fallback in ensureStaged passes the whole suite.
func TestAdoptNeverDownloadsALegacyArtifact(t *testing.T) {
	dir := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, pub := testKeys(t)
	opt, reg := t.TempDir(), testRegistry(t)

	// Built in a scratch store, then placed key by key: the qualified pointer
	// and manifest go down as they are, the artifact only in its legacy shape.
	scratch := NewDirStore(t.TempDir())
	shipRelease(t, scratch, OpsAccount, "half", "v1", adoptPlatform, []byte("build one"))
	if err := Promote(ctx, scratch, priv, OpsAccount, "half", "canary/x", "v1"); err != nil {
		t.Fatal(err)
	}
	art := ""
	keys, err := scratch.List(ctx, AppPrefix(OpsAccount, "half"))
	if err != nil {
		t.Fatal(err)
	}
	for _, k := range keys {
		body, _, err := scratch.Get(ctx, k)
		if err != nil {
			t.Fatal(err)
		}
		dst := k
		if strings.Contains(k, "/releases/") && !strings.HasSuffix(k, "manifest.json") {
			art = k
			dst = LegacyAppPrefix("half") + strings.TrimPrefix(k, AppPrefix(OpsAccount, "half"))
		}
		if _, err := dir.Put(ctx, dst, body, ""); err != nil {
			t.Fatal(err)
		}
	}
	if art == "" {
		t.Fatal("fixture: no artifact key found")
	}
	if _, _, err := dir.Get(ctx, art); !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("fixture: the qualified artifact exists (%v) — the test would prove nothing", err)
	}

	s := &legacyTripwire{Store: dir, t: t, app: "half"}
	addRoute(t, reg, "half.example.com", "half", "canary/x", false)
	if err := Pass(ctx, reg, s, pub, opt, func(string) error { return nil }); err != nil {
		t.Fatalf("one app's missing artifact must not fail the pass: %v", err)
	}
	if _, err := os.Stat(VersionPath(opt, OpsAccount, "v1", "half")); err == nil {
		t.Error("adopt staged a build whose artifact only exists at the legacy key")
	}
	if v, _ := LiveVersion(opt, "half.example.com"); v != "" {
		t.Errorf("host repointed to %q on a build that was never staged", v)
	}
}

// The other half of the bargain: the migration verb's access to legacy keys
// is EXPLICIT, and outlives the fallback. It is the upgrade path for any
// deployment arriving from a pre-accounts binary, so it works forever.
func TestGetMigrationSourceStillReadsLegacy(t *testing.T) {
	s := NewDirStore(t.TempDir())
	ctx := context.Background()
	if _, err := s.Put(ctx, LegacyChannelKey("old", "stable"), []byte("legacy"), ""); err != nil {
		t.Fatal(err)
	}
	body, _, usedLegacy, err := GetMigrationSource(ctx, s,
		ChannelKey(OpsAccount, "old", "stable"), LegacyChannelKey("old", "stable"))
	if err != nil || string(body) != "legacy" || !usedLegacy {
		t.Fatalf("migration source: body=%q usedLegacy=%v err=%v", body, usedLegacy, err)
	}
	// Qualified still wins where both exist — that precedence is what stops
	// the verb copying a stale legacy pointer over a live qualified one.
	if _, err := s.Put(ctx, ChannelKey(OpsAccount, "old", "stable"), []byte("qualified"), ""); err != nil {
		t.Fatal(err)
	}
	body, _, usedLegacy, err = GetMigrationSource(ctx, s,
		ChannelKey(OpsAccount, "old", "stable"), LegacyChannelKey("old", "stable"))
	if err != nil || string(body) != "qualified" || usedLegacy {
		t.Fatalf("qualified must win: body=%q usedLegacy=%v err=%v", body, usedLegacy, err)
	}
}

// A MIGRATED app waiting on its first promotion to a channel is ordinary,
// and must not be told to migrate. This is kass's live shape on the flagship:
// fully migrated to its own account, with a route following stable whose
// pointer does not exist until the bake window ends — so the hourly adopt
// would otherwise nag about migrating an app that is already migrated, every
// hour, forever.
//
// The distinction is the same one PromoteOnLadder makes, and it is computed
// from the qualified prefix alone: nothing there at all means the deployment
// never migrated; anything there means this channel simply has no pointer yet.
func TestAdoptDoesNotSuggestMigrationForAMigratedApp(t *testing.T) {
	s := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, pub := testKeys(t)
	opt, reg := t.TempDir(), testRegistry(t)

	// Migrated and live on its own account — just not on stable yet.
	shipRelease(t, s, "bad", "kass", "v1", adoptPlatform, []byte("build one"))
	if err := Promote(ctx, s, priv, "bad", "kass", "canary/x", "v1"); err != nil {
		t.Fatal(err)
	}
	if err := reg.Upsert(registry.Route{Host: "kass.bad.oncarlos.test", Kind: "instance",
		App: "kass", Account: "bad", Channel: "stable"}); err != nil {
		t.Fatal(err)
	}

	var out bytes.Buffer
	withCapturedStdout(t, &out, func() {
		if err := Pass(ctx, reg, s, pub, opt, func(string) error { return nil }); err != nil {
			t.Errorf("Pass: %v", err)
		}
	})
	// The PLAIN line exactly — "channel has no release yet" followed by
	// nothing. A bare Contains on the prefix would also match the hint line
	// ("channel has no release yet (…migrate…)"), making the positive half of
	// this test vacuous (2026-08-03 review): only pinning the line ending
	// keeps it a real assertion about WHICH branch printed.
	if !strings.Contains(out.String(), "channel has no release yet\n") {
		t.Errorf("want the plain skip line and nothing appended to it, got:\n%s", out.String())
	}
	if strings.Contains(out.String(), "accounts migrate") {
		t.Errorf("a migrated app was told to migrate:\n%s", out.String())
	}
}

// countingStore counts listings of one exact prefix.
type countingStore struct {
	Store
	prefix string
	n      int
}

func (c *countingStore) List(ctx context.Context, prefix string) ([]string, error) {
	if prefix == c.prefix {
		c.n++
	}
	return c.Store.List(ctx, prefix)
}

// The check that decides the line costs one listing per (account, app) per
// pass, not one per channel. A box following several of an app's channels —
// the ordinary shape for a canary fleet — must not pay for the distinction
// once per route.
func TestAdoptListsAnAppsPrefixOncePerPass(t *testing.T) {
	dir := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, pub := testKeys(t)
	opt, reg := t.TempDir(), testRegistry(t)

	shipRelease(t, dir, "bad", "kass", "v1", adoptPlatform, []byte("build one"))
	if err := Promote(ctx, dir, priv, "bad", "kass", "canary/x", "v1"); err != nil {
		t.Fatal(err)
	}
	// Three routes, three channels with no pointer, one app.
	for i, ch := range []string{"stable", "beta", "edge"} {
		if err := reg.Upsert(registry.Route{Host: fmt.Sprintf("h%d.example.com", i),
			Kind: "instance", App: "kass", Account: "bad", Channel: ch}); err != nil {
			t.Fatal(err)
		}
	}

	s := &countingStore{Store: dir, prefix: AppPrefix("bad", "kass")}
	var out bytes.Buffer
	withCapturedStdout(t, &out, func() {
		if err := Pass(ctx, reg, s, pub, opt, func(string) error { return nil }); err != nil {
			t.Errorf("Pass: %v", err)
		}
	})
	if s.n != 1 {
		t.Errorf("listed %s %d times in one pass, want 1", s.prefix, s.n)
	}
	if strings.Contains(out.String(), "accounts migrate") {
		t.Errorf("a migrated app was told to migrate:\n%s", out.String())
	}
}

// The other side of the same line: an app with NOTHING under its qualified
// prefix is the deployment that upgraded without migrating, and it gets the
// verb by name. Reserving the advice is what makes it worth reading.
func TestAdoptSuggestsMigrationForAnUnmigratedApp(t *testing.T) {
	dir := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, pub := testKeys(t)
	opt, reg := t.TempDir(), testRegistry(t)

	scratch := NewDirStore(t.TempDir())
	shipRelease(t, scratch, OpsAccount, "old", "v1", adoptPlatform, []byte("build one"))
	if err := Promote(ctx, scratch, priv, OpsAccount, "old", "stable", "v1"); err != nil {
		t.Fatal(err)
	}
	keys, err := scratch.List(ctx, AppPrefix(OpsAccount, "old"))
	if err != nil {
		t.Fatal(err)
	}
	for _, k := range keys {
		body, _, err := scratch.Get(ctx, k)
		if err != nil {
			t.Fatal(err)
		}
		legacy := LegacyAppPrefix("old") + strings.TrimPrefix(k, AppPrefix(OpsAccount, "old"))
		if _, err := dir.Put(ctx, legacy, body, ""); err != nil {
			t.Fatal(err)
		}
	}

	s := &legacyTripwire{Store: dir, t: t, app: "old"}
	addRoute(t, reg, "old.example.com", "old", "stable", false)
	var out bytes.Buffer
	withCapturedStdout(t, &out, func() {
		if err := Pass(ctx, reg, s, pub, opt, func(string) error { return nil }); err != nil {
			t.Errorf("Pass: %v", err)
		}
	})
	if !strings.Contains(out.String(), "carlos accounts migrate --app old --from legacy --to bab") {
		t.Errorf("an unmigrated app was not told how to migrate:\n%s", out.String())
	}
}

// Promoting an app on a deployment that never migrated must say SO. Left to
// the ladder, the answer is "stable is entered from beta only, and this build
// is on no rung yet" — true (nothing qualified means no rung) and entirely
// beside the point. The operator's actual problem is that this deployment's
// objects are all at the account-less keys.
//
// The test drives it through the tripwire: the distinction is computed from
// the qualified prefix alone, never by peeking at legacy.
func TestPromoteOnLadderNamesTheMigrationForAnUnmigratedApp(t *testing.T) {
	dir := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, _ := testKeys(t)
	s := &legacyTripwire{Store: dir, t: t, app: "old"}

	// A wholly legacy app, built in a scratch store and copied down.
	scratch := NewDirStore(t.TempDir())
	shipRelease(t, scratch, OpsAccount, "old", "v1", adoptPlatform, []byte("build one"))
	if err := Promote(ctx, scratch, priv, OpsAccount, "old", "stable", "v1"); err != nil {
		t.Fatal(err)
	}
	keys, err := scratch.List(ctx, AppPrefix(OpsAccount, "old"))
	if err != nil {
		t.Fatal(err)
	}
	for _, k := range keys {
		body, _, err := scratch.Get(ctx, k)
		if err != nil {
			t.Fatal(err)
		}
		legacy := LegacyAppPrefix("old") + strings.TrimPrefix(k, AppPrefix(OpsAccount, "old"))
		if _, err := dir.Put(ctx, legacy, body, ""); err != nil {
			t.Fatal(err)
		}
	}

	_, err = PromoteOnLadder(ctx, s, priv, OpsAccount, "old", "stable", "v1", PromoteOptions{})
	if err == nil {
		t.Fatal("promoting an unmigrated app succeeded")
	}
	if !strings.Contains(err.Error(), "carlos accounts migrate --app old --from legacy --to bab") {
		t.Errorf("the refusal does not name the fix:\n%v", err)
	}
	if strings.Contains(err.Error(), "no rung yet") {
		t.Errorf("the ladder answered instead of the migration:\n%v", err)
	}
}

// The control for the test above, and the reason the condition is "nothing
// qualified AT ALL" rather than "no qualified releases": an app that HAS
// shipped under this account is not unmigrated, however new the target
// channel is. It gets the ladder's answer, with no migration advice.
func TestPromoteOnLadderKeepsTheLadderRefusalForAShippedApp(t *testing.T) {
	s := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, _ := testKeys(t)

	shipRelease(t, s, OpsAccount, "fresh", "v1", adoptPlatform, []byte("build one"))
	_, err := PromoteOnLadder(ctx, s, priv, OpsAccount, "fresh", "stable", "v1", PromoteOptions{})
	if err == nil {
		t.Fatal("a fresh build entered stable directly")
	}
	if !strings.Contains(err.Error(), "no rung yet") {
		t.Errorf("want the ladder's refusal, got:\n%v", err)
	}
	if strings.Contains(err.Error(), "accounts migrate") {
		t.Errorf("a shipped app was told to migrate:\n%v", err)
	}
}

// A store error that is not "not found" is never retried against legacy:
// masking a broken bucket as a fallback miss would make it look like an
// unmigrated app, and the migration would then "verify" an app it never read.
func TestGetMigrationSourcePropagatesRealErrors(t *testing.T) {
	s := &erroringStore{err: errors.New("bucket on fire")}
	_, _, _, err := GetMigrationSource(context.Background(), s, "a", "b")
	if err == nil || !strings.Contains(err.Error(), "on fire") {
		t.Fatalf("want the real error, got %v", err)
	}
}

// Promote against an app whose pointer only exists at the legacy key does not
// see it: the new pointer is a FIRST promote at the qualified key, and the
// legacy history does not come forward. That is the retirement's real cost,
// stated — carrying history across is what `accounts migrate` is for, and it
// is why a miss names that verb. The legacy object is still never deleted.
func TestPromoteDoesNotInheritALegacyPointer(t *testing.T) {
	s := NewDirStore(t.TempDir())
	ctx := context.Background()
	priv, pub := testKeys(t)

	shipRelease(t, s, "kqmv", "myapp", "v1", "linux-amd64", []byte("v1"))
	shipRelease(t, s, "kqmv", "myapp", "v2", "linux-amd64", []byte("v2"))
	legacy, err := signPointer(RootSigner(priv), &ChannelPointer{Account: "bab", App: "myapp", Channel: "stable", Version: "v1"})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := s.Put(ctx, LegacyChannelKey("myapp", "stable"), legacy, ""); err != nil {
		t.Fatal(err)
	}

	if err := Promote(ctx, s, priv, "kqmv", "myapp", "stable", "v2"); err != nil {
		t.Fatalf("Promote: %v", err)
	}
	ptr, err := Channel(ctx, s, pub, "kqmv", "myapp", "stable")
	if err != nil {
		t.Fatal(err)
	}
	if ptr.Version != "v2" {
		t.Fatalf("pointer = %s, want v2", ptr.Version)
	}
	if len(ptr.History) != 0 {
		t.Errorf("history = %v, want empty — a legacy pointer must not be inherited", ptr.History)
	}
	if _, _, err := s.Get(ctx, LegacyChannelKey("myapp", "stable")); err != nil {
		t.Errorf("promote deleted the legacy pointer: %v", err)
	}
}