feat: show different ways we can do common the proving

common/src/msgs/data_requests/execute/commit_result.rs

@@ -1,4 +1,7 @@
+use vrf_rs::Secp256k1Sha256;
+
 use super::*;
+use crate::error::Result;
 
 #[cfg_attr(feature = "cosmwasm", cw_serde)]
 #[cfg_attr(not(feature = "cosmwasm"), derive(Serialize))]
@@ -10,6 +13,121 @@ pub struct Execute {
     pub proof:      Vec<u8>,
 }
 
+trait SignSelf {
+    const METHOD_NAME: &'static str;
+
+    fn set_proof(&mut self, proof: Vec<u8>);
+
+    // maybe needs to be an option if the struct has no fields
+    fn fields(&self) -> impl IntoIterator<Item = &[u8]>;
+
+    fn sign(&mut self, signing_key: &[u8], chain_id: &str, contract_addr: &str, seq: u128) -> Result<()> {
+        let seq = seq.to_be_bytes();
+        let msg = std::iter::once(Self::METHOD_NAME.as_bytes()).chain(self.fields().into_iter().chain([
+            chain_id.as_bytes(),
+            contract_addr.as_bytes(),
+            &seq,
+        ]));
+
+        let msg_hash = hash(msg);
+
+        let vrf = Secp256k1Sha256::default();
+        let proof = vrf.prove(signing_key, &msg_hash)?;
+
+        self.set_proof(proof);
+
+        Ok(())
+    }
+}
+
+// Option 1: Implement a trait for the structs
+impl SignSelf for Execute {
+    const METHOD_NAME: &'static str = "commit_data_result";
+
+    fn set_proof(&mut self, proof: Vec<u8>) {
+        self.proof = proof;
+    }
+
+    fn fields(&self) -> impl IntoIterator<Item = &[u8]> {
+        [self.dr_id.as_slice(), self.commitment.as_slice()]
+    }
+}
+
+// Option 2: Builder pattern
+pub struct ExecuteBuilder {
+    dr_id:      Hash,
+    commitment: Hash,
+    public_key: PublicKey,
+}
+
+impl ExecuteBuilder {
+    pub fn new(dr_id: Hash, commitment: Hash, public_key: PublicKey) -> Self {
+        ExecuteBuilder {
+            dr_id,
+            commitment,
+            public_key,
+        }
+    }
+
+    pub fn build(self, signing_key: &[u8], chain_id: &str, contract_addr: &str, seq: u128) -> Result<Execute> {
+        let msg_hash = hash([
+            "commit_data_result".as_bytes(),
+            &self.dr_id,
+            &self.commitment,
+            chain_id.as_bytes(),
+            contract_addr.as_bytes(),
+            &seq.to_be_bytes(),
+        ]);
+
+        let vrf = Secp256k1Sha256::default();
+
+        let execute = Execute {
+            dr_id:      self.dr_id,
+            commitment: self.commitment,
+            public_key: self.public_key,
+            proof:      vrf.prove(signing_key, &msg_hash)?,
+        };
+
+        Ok(execute)
+    }
+}
+
+// Option 3: long new function
+impl Execute {
+    #[allow(clippy::too_many_arguments)]
+    pub fn new(
+        signing_key: &[u8],
+        dr_id: Hash,
+        commitment: Hash,
+        public_key: PublicKey,
+        height: u64,
+        chain_id: &str,
+        contract_addr: &str,
+        seq: u128,
+    ) -> Result<Self> {
+        let msg_hash = hash([
+            "commit_data_result".as_bytes(),
+            &dr_id,
+            // this one does expect a height... but I think this is wrong and we should remove that??
+            &height.to_be_bytes(),
+            &commitment,
+            chain_id.as_bytes(),
+            contract_addr.as_bytes(),
+            &seq.to_be_bytes(),
+        ]);
+
+        // We should lazy static or something to avoid creating a new instance every time
+        let vrf = Secp256k1Sha256::default();
+
+        Ok(Execute {
+            dr_id,
+            commitment,
+            public_key,
+            proof: vrf.prove(signing_key, &msg_hash)?,
+        })
+    }
+}
+
 impl From<Execute> for crate::msgs::ExecuteMsg {
     fn from(value: Execute) -> Self {
         super::ExecuteMsg::CommitDataResult(value).into()