Error messages for downloads

src/errors.rs

@@ -281,10 +281,12 @@ pub enum AviaryDownloadError {
 	/// An important reason this might occur is if the gallery expired and the server re-assigned
 	/// the ID to another file, and both used the .bin extension.
 	///
-	/// Handling:  If this occurs for an image where the URL and key are both provided by the
+	/// Note:  If there is a key mismatch for an image in a gallery, rather than on the index, this
-	/// index, it should always be interpreted as an expiration.  If it occurs for an index, ask
+	/// should be interpretted as an expiration instead, and should use the [`ExpiredImage`][]
-	/// the user to verify that they key and file ID were copied correctly, and if they are
+	/// variant.
-	/// correct, then the gallery expired.
+	///
+	/// Handling:  Ask the user to verify that they key and file ID were copied correctly, and if
+	/// they are correct, then the gallery expired.
 	KeyMismatch,
 
 	/// Indicates that the index did not conform to the protobuf spec
@@ -376,3 +378,125 @@ impl AviaryDownloadError {
 		}
 	}}
 }
+
+impl fmt::Display for AviaryDownloadError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		if let AviaryDownloadError::Cancelled = self {
+			writeln!(f, "\x1b[31mCancelled\x1b[0m")?;
+		} else {
+			writeln!(f, "\x1b[31mError!\x1b[0m\n")?;
+		}
+		match self {
+			AviaryDownloadError::MalformedKey(invalid) =>
+				write!(f, concat!(
+					"It looks like that key {}  Double check to make sure that you ",
+					"copied it correctly.  If you did, ask the person who sent you the ",
+					"link to make sure that /they/ copied it correctly."
+				), if *invalid {
+					"isn't valid base64, and won't work here."
+				} else {
+					"is the wrong length!"
+				}),
+			AviaryDownloadError::ServerError(err_code, msg) =>
+				write!(f, concat!(
+					"The server storing this gallery seems to be behaving in a way we ",
+					"didn't expect.  Double check to make sure that you've set the ",
+					"correct instance with \x1b[35m-s\x1b[0m/\x1b[35m--server\x1b[0m, ",
+					"and if the problem persists, reach out the server administrator to ",
+					"let them know that something went wrong.\n\n",
+					"This information might help to diagnose the issue:\n\x1b[31m{}",
+				), if let Some(err_code) = err_code {
+					format!("Error code {:03}:\n{}", err_code, &msg[..usize::min(50, msg.len())])
+				} else {
+					format!("Server misbehaviour: {}", msg)
+				}),
+			AviaryDownloadError::PermissionDenied(path) =>
+				write!(f, concat!(
+					"It looks like you don't have permission for the directory you're ",
+					"trying to download this album into.  Specifically, permission was ",
+					"denied for \x1b[36m{}\x1b[0m\n\n",
+					"Try acquiring permission, or picking a different directory with ",
+					"\x1b[35m-ox1b[0m/x1b[35m--outputx1b[0m."
+				), path.display()),
+			AviaryDownloadError::FilesystemError(err, path) =>
+				write!(f, concat!(
+					"Some uncommon filesystem error happened while we were trying to ",
+					"write to/create \x1b[36m{}\x1b[0m.  This shouldn't happen very ",
+					"often, but here's a few guesses as to what might have happened:\n",
+					"\x1b[37m- \x1b[0mA disk was ejected while we were saving a file\n",
+					"\x1b[37m- \x1b[0mYou're using a special filesystem that ",
+					"encountered an error\n",
+					"\x1b[37m- \x1b[0mThe disk you were writing to is read only\n\n",
+					"If you're getting this error and you don't know why, we'd really ",
+					"appreciate it if you could open an issue on our bug tracker.  Even ",
+					"just the filesystem you were using and the error you got could be ",
+					"enough to help.\n\n",
+					"The full error that we got is:\n\x1b[31m{:?}",
+				), path.display(), err),
+			AviaryDownloadError::BadServerParameter =>
+				write!(f, concat!(
+					"Oops!  The server you entered looks like it might not be correct.  ",
+					"Double check that your \x1b[35m-s\x1b[0m/\x1b[35m--server\x1b[0m ",
+					"parameter is correct"
+				)),
+			AviaryDownloadError::ConnectionError(msg) =>
+				write!(f, concat!(
+					"There was an issue connecting to the server!  Check that your ",
+					"internet is online, and you can access websites normally.  ",
+					"This information might help diagnose the issue:\n\n",
+					"\x1b[31m{}\x1b[0m"
+				), msg),
+			AviaryDownloadError::MissingIndex =>
+				write!(f, concat!(
+					"No album found at this URL!  Double check that the file ID you ",
+					"entered is correct and that you've specified the right instance ",
+					"using \x1b[35m-s\x1b[0m/\x1b[35m--server\x1b[0m.  If you have, this ",
+					"album may have expired."
+				)),
+			AviaryDownloadError::ExpiredImage =>
+				write!(f, concat!(
+					"One or more images in this album have expired.  Currently, the ",
+					"command line tool has no support for downloading partially expired ",
+					"albums, although this may change in the future.  Please contact the ",
+					"original uploader to get a new album link."
+				)),
+			AviaryDownloadError::KeyMismatch =>
+				write!(f, concat!(
+					"Wrong key!  Either the base64 key that you entered isn't right, or ",
+					"it doesn't go to this album.  Double check that you've copied both ",
+					"the album ID and the key correctly.  If you're not using the main ",
+					"instance, you should also double check that you've set the ",
+					"\x1b[35m-s\x1b[0m/\x1b[35m--server\x1b[0m.  If all of this is ",
+					"correct, then the album may be expired."
+				)),
+			AviaryDownloadError::CorruptIndex(msg) =>
+				write!(f, concat!(
+					"Something very strange has occurred.  \x1b[31;1mIf you are a ",
+					"non-technical user, feel free to stop here and open an issue, and ",
+					"we can help figure out why this happened and how we can stop it ",
+					"from happening in the future.\x1b[0m  If you are a technical user, ",
+					"read on to learn what happened.\n\n",
+					"The index which stores a listing of the files in this album (along ",
+					"with metadata like the title and description) was corrupt.  ",
+					"However, the decryption was succeeded, including the MAC ",
+					"checking.  This could stem from a couple possibilities:\n",
+					"\x1b[37m- \x1b[0mThe key/file id pair provided was valid, but ",
+					"points to an image rather than a gallery\n",
+					"\x1b[37m- \x1b[0mA very poorly behaved client generated this ",
+					"album, and produced a corrupt index\n",
+					"\x1b[37m- \x1b[0mThis is a key/file pair which is meant to be ",
+					"used with a different project with a very similar encryption scheme\n\n",
+					"The specific error is as follows:\n\x1b[31m{}"
+				), msg),
+			AviaryDownloadError::NotOverwriting(path) =>
+				write!(f, concat!(
+					"The file \x1b[36m{}\x1b[0m already exists!  To keep your data ",
+					"safe, we won't overwrite it unless you pass the ",
+					"\x1b[35m-f\x1b[0m/\x1b[35m--force\x1b[0m flag.  Consider removing ",
+					"the file yourself or choosing a new directory with the ",
+					"\x1b[35m-o\x1b[0m/\x1b[35m--output\x1b[0m flag.",
+				), path.display()),
+			AviaryDownloadError::Cancelled => Ok(()),
+		}
+	}
+}

src/main.rs

@@ -46,7 +46,10 @@ fn main() {
 	};
 	match args.command {
 		Command::Create(create_args) => create(&*full_server, create_args),
-		Command::Download(download_args) => download(&*full_server, download_args).unwrap(),
+		Command::Download(download_args) =>
+			if let Err(e) = download(&*full_server, download_args) {
+				println!("{e}")
+			},
 	}
 }