cli: classify video-download failures into specific codes

Replace the generic `error` on every download-path failure with specific codes:
response_parse_error (unparseable video-get response / unusable URL), network_error
(transport), download_url_expired (403/404 on the presigned asset URL),
asset_download_failed (asset-host 5xx/other), download_interrupted (mid-stream),
file_io_error (local temp/finalize/rename), internal_error (encoding our own output).
Each carries an actionable hint. No exit-code changes.

asset_download_failed is intentionally CLI-specific: the API's own `download_failed`
is a 400 for a bad user-provided input URL (opposite meaning), so reusing it would
collide.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: somanshreddy

cmd/heygen/video_download.go

@@ -104,7 +104,11 @@ func newVideoDownloadCmd(ctx *cmdContext) *cobra.Command {
 				"path":    dest,
 			})
 			if err != nil {
-				return clierrors.New(fmt.Sprintf("failed to encode response: %v", err))
+				return &clierrors.CLIError{
+					Code:     "internal_error",
+					Message:  fmt.Sprintf("failed to encode response: %v", err),
+					ExitCode: clierrors.ExitGeneral,
+				}
 			}
 
 			return ctx.formatter.Data(data, "", nil)
@@ -122,7 +126,12 @@ func extractAssetURL(raw json.RawMessage, videoID string, info assetInfo) (strin
 		Data map[string]json.RawMessage `json:"data"`
 	}
 	if err := json.Unmarshal(raw, &resp); err != nil {
-		return "", clierrors.New("failed to parse video response")
+		return "", &clierrors.CLIError{
+			Code:     "response_parse_error",
+			Message:  "failed to parse the video response",
+			Hint:     "The API response could not be parsed. Retry; if it persists, report it (possible CLI/API mismatch).",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 
 	var status string
@@ -180,45 +189,90 @@ func assetHint(field string) string {
 func downloadFile(ctx context.Context, videoURL, dest string) error {
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, videoURL, nil)
 	if err != nil {
-		return clierrors.New(fmt.Sprintf("failed to build download request: %v", err))
+		return &clierrors.CLIError{
+			Code:     "response_parse_error",
+			Message:  fmt.Sprintf("the download URL returned by the API is unusable: %v", err),
+			Hint:     "Re-fetch a fresh URL: heygen video get <video_id>",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 
 	resp, err := downloadClient.Do(req)
 	if err != nil {
-		return clierrors.New(fmt.Sprintf("failed to download video: %v", err))
+		return &clierrors.CLIError{
+			Code:     "network_error",
+			Message:  fmt.Sprintf("failed to download video: %v", err),
+			Hint:     "This is usually a temporary network issue. Check your connection and retry.",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
-		return clierrors.New(fmt.Sprintf("download failed with HTTP %d", resp.StatusCode))
+		// A presigned asset URL that 403s/404s is expired or revoked (client can
+		// re-fetch); any other status is the asset host (our storage/CDN) failing.
+		if resp.StatusCode == http.StatusForbidden || resp.StatusCode == http.StatusNotFound {
+			return &clierrors.CLIError{
+				Code:     "download_url_expired",
+				Message:  fmt.Sprintf("download link expired or unavailable (HTTP %d)", resp.StatusCode),
+				Hint:     "This download link has expired. Re-fetch a fresh URL: heygen video get <video_id>",
+				ExitCode: clierrors.ExitGeneral,
+			}
+		}
+		return &clierrors.CLIError{
+			Code:     "asset_download_failed",
+			Message:  fmt.Sprintf("download failed with HTTP %d", resp.StatusCode),
+			Hint:     "The asset host returned an error fetching the file. This is usually transient — retry shortly.",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 
 	// Write to a temp file in the same directory, then rename on success.
 	// This prevents destroying an existing file on partial download failure.
 	dir := filepath.Dir(dest)
 	tmp, err := os.CreateTemp(dir, ".heygen-download-*.tmp")
 	if err != nil {
-		return clierrors.New(fmt.Sprintf("failed to create temp file in %q: %v", dir, err))
+		return &clierrors.CLIError{
+			Code:     "file_io_error",
+			Message:  fmt.Sprintf("failed to create temp file in %q: %v", dir, err),
+			Hint:     "Could not write locally. Check the destination path and free disk space.",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 	tmpPath := tmp.Name()
 
 	_, copyErr := io.Copy(tmp, resp.Body)
 	closeErr := tmp.Close()
 	if copyErr != nil {
 		_ = os.Remove(tmpPath)
-		return clierrors.New(fmt.Sprintf("download interrupted: %v", copyErr))
+		return &clierrors.CLIError{
+			Code:     "download_interrupted",
+			Message:  fmt.Sprintf("download interrupted: %v", copyErr),
+			Hint:     "The transfer was cut off. Retry; the partial file was cleaned up.",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 	if closeErr != nil {
 		_ = os.Remove(tmpPath)
-		return clierrors.New(fmt.Sprintf("failed to finalize download: %v", closeErr))
+		return &clierrors.CLIError{
+			Code:     "file_io_error",
+			Message:  fmt.Sprintf("failed to finalize download: %v", closeErr),
+			Hint:     "Could not finalize the file locally. Check free disk space.",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 
 	// Atomic rename. On Windows this may fail if dest is open elsewhere;
 	// os.Rename across filesystems also fails, but temp file is in the
 	// same directory so this is safe.
 	if err := os.Rename(tmpPath, dest); err != nil {
 		_ = os.Remove(tmpPath)
-		return clierrors.New(fmt.Sprintf("failed to move download to %q: %v", dest, err))
+		return &clierrors.CLIError{
+			Code:     "file_io_error",
+			Message:  fmt.Sprintf("failed to move download to %q: %v", dest, err),
+			Hint:     "Could not write to the destination path. Check permissions and free disk space.",
+			ExitCode: clierrors.ExitGeneral,
+		}
 	}
 
 	return nil

cmd/heygen/video_download_test.go

@@ -405,11 +405,50 @@ func TestVideoDownload_DownloadFails(t *testing.T) {
 	if res.ExitCode != 1 {
 		t.Fatalf("ExitCode = %d, want 1\nstderr: %s", res.ExitCode, res.Stderr)
 	}
+	if !strings.Contains(res.Stderr, `"code":"asset_download_failed"`) {
+		t.Fatalf("stderr should carry asset_download_failed (asset-host 5xx):\n%s", res.Stderr)
+	}
 	if _, err := os.Stat(dest); !os.IsNotExist(err) {
 		t.Fatalf("expected no output file, stat err = %v", err)
 	}
 }
 
+// A presigned asset URL that 403s (or 404s) is expired/revoked — a client-side
+// download_url_expired, distinct from the asset host failing (asset_download_failed).
+func TestVideoDownload_ExpiredURL(t *testing.T) {
+	tmpDir := t.TempDir()
+	dest := filepath.Join(tmpDir, "expired.mp4")
+
+	var srv *httptest.Server
+	srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.Method == http.MethodGet && r.URL.Path == "/v3/videos/vid_123":
+			writeJSON(t, w, map[string]any{
+				"data": map[string]any{
+					"video_url": srv.URL + "/download/expired.mp4",
+					"status":    "completed",
+				},
+			})
+		case r.Method == http.MethodGet && r.URL.Path == "/download/expired.mp4":
+			w.WriteHeader(http.StatusForbidden)
+		default:
+			t.Fatalf("unexpected request: %s %s", r.Method, r.URL.Path)
+		}
+	}))
+	defer srv.Close()
+
+	res := runCommand(t, srv.URL, "test-key", "video", "download", "vid_123", "--output-path", dest)
+	if res.ExitCode != 1 {
+		t.Fatalf("ExitCode = %d, want 1\nstderr: %s", res.ExitCode, res.Stderr)
+	}
+	if !strings.Contains(res.Stderr, `"code":"download_url_expired"`) {
+		t.Fatalf("stderr should carry download_url_expired (403 on presigned URL):\n%s", res.Stderr)
+	}
+	if !strings.Contains(res.Stderr, "video get") {
+		t.Fatalf("expired-URL hint should point to re-fetching via video get:\n%s", res.Stderr)
+	}
+}
+
 func TestVideoDownload_AuthRequired(t *testing.T) {
 	srv := setupTestServer(t, map[string]testHandler{})
 	defer srv.Close()