More management tools

pkg/whatsapp/businessapi/media.go

@@ -8,6 +8,8 @@ import (
 	"io"
 	"mime/multipart"
 	"net/http"
+	"net/textproto"
+	"strings"
 )
 
 // UploadMedia uploads a media file to Meta and returns the media ID.
@@ -26,8 +28,16 @@ func (c *Client) uploadMedia(ctx context.Context, data []byte, mimeType string)
 	var requestBody bytes.Buffer
 	writer := multipart.NewWriter(&requestBody)
 
-	// Add the file
-	part, err := writer.CreateFormFile("file", "media")
+	if strings.TrimSpace(mimeType) == "" {
+		mimeType = "application/octet-stream"
+	}
+
+	// Add the file with explicit MIME type so Meta does not treat it as octet-stream.
+	fileHeader := make(textproto.MIMEHeader)
+	fileHeader.Set("Content-Disposition", `form-data; name="file"; filename="media"`)
+	fileHeader.Set("Content-Type", mimeType)
+
+	part, err := writer.CreatePart(fileHeader)
 	if err != nil {
 		return "", fmt.Errorf("failed to create form file: %w", err)
 	}