Convert dht doc to dns packet (#224)

* Convert dht doc to dns packet

* Add happy path tests for alsoKnownAs and controller

* Update crates/dids/src/methods/dht/document_packet/mod.rs

Co-authored-by: nitro-neal <[email protected]>

---------

Co-authored-by: nitro-neal <[email protected]>

crates/dids/src/methods/dht/document_packet/also_known_as.rs

@@ -0,0 +1,75 @@
+use simple_dns::{
+    rdata::{RData, TXT},
+    Name, ResourceRecord,
+};
+
+use super::{rdata_encoder::text_from_record, DocumentPacketError, DEFAULT_TTL};
+
+pub struct AlsoKnownAs {}
+
+impl AlsoKnownAs {
+    pub fn is_aka_record(record: &ResourceRecord) -> bool {
+        match record.name.get_labels().first() {
+            None => false,
+            Some(domain) => domain.to_string() == "_aka",
+        }
+    }
+
+    pub fn to_resource_record(
+        also_known_as: &[String],
+    ) -> Result<ResourceRecord, DocumentPacketError> {
+        let name = Name::new_unchecked("_aka._did.");
+        let txt_record = TXT::new()
+            .with_string(&also_known_as.join(","))?
+            .into_owned();
+
+        Ok(ResourceRecord::new(
+            name,
+            simple_dns::CLASS::IN,
+            DEFAULT_TTL,
+            RData::TXT(txt_record),
+        ))
+    }
+
+    pub fn from_resource_record(
+        record: &ResourceRecord,
+    ) -> Result<Vec<String>, DocumentPacketError> {
+        let text = text_from_record(record)?;
+        let also_known_as = text
+            .split(',')
+            .map(|s| s.to_string())
+            .filter(|s| !s.is_empty())
+            .collect();
+        Ok(also_known_as)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::methods::dht::document_packet::controller::Controller;
+
+    use super::*;
+
+    #[test]
+    fn test_to_and_from_resource_record() {
+        let also_known_as = vec!["Dave".to_string(), "Bartholemoop".to_string()];
+        let record = AlsoKnownAs::to_resource_record(&also_known_as)
+            .expect("expected to convert to DNS record");
+        let also_known_as2 = AlsoKnownAs::from_resource_record(&record)
+            .expect("Expected to convert from DNS record");
+        assert_eq!(also_known_as, also_known_as2);
+    }
+
+    #[test]
+    fn test_is_aka_record() {
+        let also_known_as = vec!["Dave".to_string(), "Bartholemoop".to_string()];
+        let record = AlsoKnownAs::to_resource_record(&also_known_as)
+            .expect("expected to convert to DNS record");
+
+        assert!(AlsoKnownAs::is_aka_record(&record));
+
+        let controllers = vec!["Jerb".to_string(), "Carrie Bradshaw".to_string()];
+        let record = Controller::to_resource_record(&controllers).unwrap();
+        assert!(!AlsoKnownAs::is_aka_record(&record));
+    }
+}

crates/dids/src/methods/dht/document_packet/controller.rs

@@ -0,0 +1,80 @@
+use simple_dns::{
+    rdata::{RData, TXT},
+    Name, ResourceRecord,
+};
+
+use super::{rdata_encoder::text_from_record, DocumentPacketError, DEFAULT_TTL};
+
+pub struct Controller {}
+
+impl Controller {
+    pub fn is_cnt_record(record: &ResourceRecord) -> bool {
+        match record.name.get_labels().first() {
+            None => false,
+            Some(domain) => domain.to_string() == "_cnt",
+        }
+    }
+
+    pub fn to_resource_record(
+        controllers: &[String],
+    ) -> Result<ResourceRecord, DocumentPacketError> {
+        let name = Name::new_unchecked("_cnt._did.");
+        let txt_record = TXT::new().with_string(&controllers.join(","))?.into_owned();
+
+        Ok(ResourceRecord::new(
+            name,
+            simple_dns::CLASS::IN,
+            DEFAULT_TTL,
+            RData::TXT(txt_record),
+        ))
+    }
+
+    pub fn from_resource_record(
+        record: &ResourceRecord,
+    ) -> Result<Vec<String>, DocumentPacketError> {
+        let text = text_from_record(record)?;
+        let controllers = text
+            .split(',')
+            .map(|s| s.to_string())
+            .filter(|s| !s.is_empty())
+            .collect();
+        Ok(controllers)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::methods::dht::document_packet::also_known_as::AlsoKnownAs;
+
+    use super::*;
+
+    #[test]
+    fn to_and_from_resource_record() {
+        let controllers = vec![];
+        let record = Controller::to_resource_record(&controllers)
+            .expect("Expected to create controller resource record");
+        let controllers2 = Controller::from_resource_record(&record)
+            .expect("Expected to get a list of strings from resource record");
+        assert_eq!(controllers, controllers2);
+
+        let controllers = vec!["did:dht:123".to_string(), "did:dht:456".to_string()];
+        let record = Controller::to_resource_record(&controllers)
+            .expect("Expected to create controller resource record");
+        let controllers2 = Controller::from_resource_record(&record)
+            .expect("Expected to get a list of strings from resource record");
+        assert_eq!(controllers, controllers2);
+    }
+
+    #[test]
+    fn test_is_cnt_record() {
+        let also_known_as = vec!["Dave".to_string(), "Bartholemoop".to_string()];
+        let record = Controller::to_resource_record(&also_known_as)
+            .expect("expected to convert to DNS record");
+
+        assert!(Controller::is_cnt_record(&record));
+
+        let controllers = vec!["Jerb".to_string(), "Carrie Bradshaw".to_string()];
+        let record = AlsoKnownAs::to_resource_record(&controllers).unwrap();
+        assert!(!Controller::is_cnt_record(&record));
+    }
+}