feat(dataverse): introduce dataverse credential model

contracts/okp4-dataverse/src/registrar/credential.rs

@@ -0,0 +1,67 @@
+use crate::credential::rdf_marker::IRI_VC_TYPE;
+use crate::credential::vc::VerifiableCredential;
+use crate::ContractError;
+use cosmwasm_std::Addr;
+use itertools::Itertools;
+use okp4_rdf::dataset::Dataset;
+
+#[derive(Debug, PartialEq)]
+pub struct DataverseCredential<'a> {
+    pub submitter_addr: Addr,
+    pub id: &'a str,
+    pub issuer: &'a str,
+    pub r#type: &'a str,
+    pub valid_from: &'a str,
+    pub valid_until: Option<&'a str>,
+    pub subject: &'a str,
+    pub claim: &'a Dataset<'a>,
+}
+
+impl<'a> DataverseCredential<'a> {
+    fn extract_vc_type(vc: &'a VerifiableCredential<'a>) -> Result<&'a str, ContractError> {
+        vc.types
+            .iter()
+            .filter(|t| *t != &IRI_VC_TYPE)
+            .exactly_one()
+            .map_err(|_| {
+                ContractError::UnsupportedCredential(
+                    "credential is expected to have exactly one type".to_string(),
+                )
+            })
+            .map(|t| *t)
+    }
+
+    fn extract_vc_claim(
+        vc: &'a VerifiableCredential<'a>,
+    ) -> Result<(&'a str, &'a Dataset<'a>), ContractError> {
+        vc.claims
+            .iter()
+            .exactly_one()
+            .map(|claim| (claim.id, &(claim.content)))
+            .map_err(|_| {
+                ContractError::UnsupportedCredential(
+                    "credential is expected to contain exactly one claim".to_string(),
+                )
+            })
+    }
+}
+
+impl<'a> TryFrom<(Addr, &'a VerifiableCredential<'a>)> for DataverseCredential<'a> {
+    type Error = ContractError;
+
+    fn try_from(
+        (submitter_addr, vc): (Addr, &'a VerifiableCredential<'a>),
+    ) -> Result<Self, Self::Error> {
+        let (subject, claim) = DataverseCredential::extract_vc_claim(vc)?;
+        Ok(DataverseCredential {
+            submitter_addr,
+            id: vc.id,
+            issuer: vc.issuer,
+            r#type: DataverseCredential::extract_vc_type(vc)?,
+            valid_from: vc.issuance_date,
+            valid_until: vc.expiration_date,
+            subject,
+            claim,
+        })
+    }
+}