feat: with protobuf

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/crunch-envelope/src/proto_envelope.rs

@@ -0,0 +1,30 @@
+pub mod envelope {
+    include!(concat!(env!("OUT_DIR"), "/crunch.envelope.rs"));
+}
+
+use prost::Message;
+
+use crate::EnvelopeError;
+
+pub fn wrap<'a>(domain: &'a str, entity: &'a str, content: &'a [u8]) -> Vec<u8> {
+    let out = envelope::Envelope {
+        metadata: Some(envelope::Metadata {
+            domain: domain.to_string(),
+            entity: entity.to_string(),
+            timestamp: 0,
+            sequence: 0,
+        }),
+        content: content.to_vec(),
+    };
+
+    out.encode_to_vec()
+}
+
+pub fn unwrap<'a>(message: &'a [u8]) -> Result<(Vec<u8>, envelope::Metadata), EnvelopeError> {
+    let out = envelope::Envelope::decode(message).map_err(EnvelopeError::ProtoError)?;
+
+    Ok((
+        out.content,
+        out.metadata.ok_or(EnvelopeError::MetadataError())?,
+    ))
+}