Implemented shared S3 audio caching for prepare and restore --include-audio

internal/app/restore_execution_test.go

@@ -87,6 +87,44 @@ func TestExecuteRestoreIncludeAudioRestoresAudio(t *testing.T) {
 	}
 }
 
+func TestExecuteRestoreIncludeAudioUsesCacheAfterWorkspaceDeletion(t *testing.T) {
+	workspaceRoot := t.TempDir()
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+
+	fake := &storage.FakeBackend{}
+	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
+	audioKey := sessionPrefix + "audio/alice.flac"
+	seedRestoreObject(fake, audioKey, []byte("remote-audio"))
+
+	restoreWithStoreAndRealPhases(t, fake)
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--include-audio"}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("first restore exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+	if got := fakeDownloadCount(fake, audioKey); got != 1 {
+		t.Fatalf("audio downloads after first restore = %d, want 1", got)
+	}
+	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
+	mustReadEquals(t, filepath.Join(sessionRoot, "audio", "alice.flac"), "remote-audio")
+
+	if err := os.RemoveAll(sessionRoot); err != nil {
+		t.Fatalf("remove session root: %v", err)
+	}
+	stdout.Reset()
+	stderr.Reset()
+	code = Execute([]string{"restore", "--config", pipelinePath, "--campaign", campaignPath, "--session", sessionPath, "--include-audio"}, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("second restore exit code = %d, want 0; stderr=%q", code, stderr.String())
+	}
+	if got := fakeDownloadCount(fake, audioKey); got != 1 {
+		t.Fatalf("audio downloads after cached restore = %d, want still 1", got)
+	}
+	mustReadEquals(t, filepath.Join(sessionRoot, "audio", "alice.flac"), "remote-audio")
+}
+
 func TestExecuteRestoreRestoresPreviousCacheWhenPresent(t *testing.T) {
 	workspaceRoot := t.TempDir()
 	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
@@ -374,6 +412,16 @@ func mustReadEquals(t *testing.T, path, want string) {
 	}
 }
 
+func fakeDownloadCount(fake *storage.FakeBackend, key string) int {
+	count := 0
+	for _, call := range fake.Downloads {
+		if call.Key == key {
+			count++
+		}
+	}
+	return count
+}
+
 type stagedManifestDownloadStore struct {
 	delegate       *storage.FakeBackend
 	manifestKey    string