let uploader set a collection name for a multiple-file upload

src/upload.rs

@@ -20,6 +20,10 @@ const MAX_FILES: usize = 256;
 const FILENAME_DATE_FORMAT: &[time::format_description::FormatItem] =
     time::macros::format_description!("[year]-[month]-[day]-[hour][minute][second]");
 
+fn sanitise(name: &str) -> String {
+    sanitise_file_name::sanitise(&name.nfd().collect::<String>())
+}
+
 #[derive(thiserror::Error, Debug)]
 enum Error {
     #[error("Failed to parse file metadata")]
@@ -104,7 +108,7 @@ pub struct UploadedFile {
 impl UploadedFile {
     fn new(name: &str, size: u64, modtime: OffsetDateTime) -> Self {
         Self {
-            name: sanitise_file_name::sanitise(&name.nfd().collect::<String>()),
+            name: sanitise(name),
             size,
             modtime,
         }
@@ -134,6 +138,7 @@ struct UploadManifest {
     files: Vec<RawUploadedFile>,
     lifetime: u16,
     password: String,
+    collection_name: Option<String>,
 }
 
 #[derive(Serialize)]
@@ -229,6 +234,7 @@ impl Uploader {
                     files: raw_files,
                     lifetime,
                     password,
+                    collection_name,
                 } = serde_json::from_slice(text.as_bytes())?;
                 if std::env::var("TRANSBEAM_UPLOAD_PASSWORD") != Ok(password) {
                     return Err(Error::IncorrectPassword);
@@ -277,9 +283,13 @@ impl Uploader {
                     let now = OffsetDateTime::now_utc();
                     let zip_writer = super::zip::ZipGenerator::new(files.clone(), writer);
                     let size = zip_writer.total_size();
-                    let download_filename = super::APP_NAME.to_owned()
-                        + &now.format(FILENAME_DATE_FORMAT).unwrap()
-                        + ".zip";
+                    let download_filename = collection_name
+                        .map(|f| sanitise(&(f + ".zip")))
+                        .unwrap_or_else(|| {
+                            super::APP_NAME.to_owned()
+                                + &now.format(FILENAME_DATE_FORMAT).unwrap()
+                                + ".zip"
+                        });
                     (Box::new(zip_writer), download_filename, size, now)
                 } else {
                     (