Decode choices

Author: stanislav-tkach

rust/catalyst-contest/src/choices.rs

@@ -37,8 +37,34 @@ impl Decode<'_, ()> for Choices {
         d: &mut Decoder<'_>,
         ctx: &mut (),
     ) -> Result<Self, minicbor::decode::Error> {
-        // TODO: FIXME:
-        todo!()
+        let len = decode_array_len(d, "choices")?;
+        if len < 2 {
+            return Err(minicbor::decode::Error::message(format!(
+                "Unexpected choices array length {len}, expected at least 2"
+            )));
+        }
+        match u8::decode(d, ctx)? {
+            0 => Ok(Self::Clear(<Vec<i64>>::decode(d, ctx)?)),
+            1 => {
+                let len = decode_array_len(d, "elgamal-ristretto255-encrypted-choices")?;
+                if len < 1 || len > 2 {
+                    return Err(minicbor::decode::Error::message(format!(
+                        "Unexpected elgamal-ristretto255-encrypted-choices array length {len}, expected 1 or 2"
+                    )));
+                }
+                let choices = <Vec<ElgamalRistretto255Choice>>::decode(d, ctx)?;
+                let mut row_proof = None;
+                if len == 2 {
+                    row_proof = Some(RowProof::decode(d, ctx)?);
+                }
+                Ok(Self::ElgamalRistretto255 { choices, row_proof })
+            },
+            val => {
+                Err(minicbor::decode::Error::message(format!(
+                    "Unexpected choices value: {val}"
+                )))
+            },
+        }
     }
 }
 
@@ -75,10 +101,10 @@ impl Decode<'_, ()> for ElgamalRistretto255Choice {
         d: &mut Decoder<'_>,
         ctx: &mut (),
     ) -> Result<Self, minicbor::decode::Error> {
-        let len = decode_array_len(d, "encrypted choices")?;
+        let len = decode_array_len(d, "elgamal ristretto255 choice")?;
         if len != 2 {
             return Err(minicbor::decode::Error::message(format!(
-                "Unexpected encrypted choices array length: {len}, expected 2"
+                "Unexpected elgamal ristretto255 choice array length: {len}, expected 2"
             )));
         }
         let c1 = <[u8; 32]>::decode(d, ctx)?;

rust/catalyst-contest/src/contest_ballot.rs

@@ -2,6 +2,7 @@
 
 use std::collections::BTreeMap;
 
+use cbork_utils::decode_helper::decode_map_len;
 use minicbor::{Decode, Decoder, Encode, Encoder, encode::Write};
 
 use crate::{Choices, ColumnProof, EncryptedChoices, MatrixProof};
@@ -24,8 +25,11 @@ impl Decode<'_, ()> for ContentBallot {
         d: &mut Decoder<'_>,
         ctx: &mut (),
     ) -> Result<Self, minicbor::decode::Error> {
-        d.map()?;
+        let len = decode_map_len(d, "content ballot")?;
         // TODO: FIXME:
+        for _ in 0..len {
+            // TODO: FIXME:
+        }
         todo!()
     }
 }
@@ -34,7 +38,7 @@ impl Encode<()> for ContentBallot {
     fn encode<W: Write>(
         &self,
         e: &mut Encoder<W>,
-        ctx: &mut (),
+        _ctx: &mut (),
     ) -> Result<(), minicbor::encode::Error<W::Error>> {
         let len = self.choices.len() as u64
             + self.column_proof.is_some() as u64

rust/catalyst-contest/src/lib.rs

@@ -5,7 +5,7 @@
 //! [documentation]: https://docs.dev.projectcatalyst.io/libs/main/architecture/08_concepts/signed_doc/docs/contest_ballot/
 
 // TODO: FIXME:
-#![allow(unused_variables)]
+//#![allow(unused_variables)]
 
 mod choices;
 mod column_proof;