From d299209142451bac43fe48db2f2f440693bd9c28 Mon Sep 17 00:00:00 2001
From: Lucas Meier <lucas@cronokirby.com>
Date: Wed, 29 Jan 2025 23:14:33 -0800
Subject: [PATCH] Implement stateless handler for LQT voting

---
 .../liquidity_tournament/mod.rs               | 76 +++++++++++++++++++
 .../funding/src/action_handler/mod.rs         |  1 +
 crates/core/component/funding/src/lib.rs      |  2 +
 3 files changed, 79 insertions(+)
 create mode 100644 crates/core/component/funding/src/action_handler/liquidity_tournament/mod.rs
 create mode 100644 crates/core/component/funding/src/action_handler/mod.rs

diff --git a/crates/core/component/funding/src/action_handler/liquidity_tournament/mod.rs b/crates/core/component/funding/src/action_handler/liquidity_tournament/mod.rs
new file mode 100644
index 0000000000..0e5bb91054
--- /dev/null
+++ b/crates/core/component/funding/src/action_handler/liquidity_tournament/mod.rs
@@ -0,0 +1,76 @@
+use anyhow::Context as _;
+use async_trait::async_trait;
+use cnidarium::StateWrite;
+use penumbra_sdk_asset::asset::Denom;
+use penumbra_sdk_proof_params::DELEGATOR_VOTE_PROOF_VERIFICATION_KEY;
+use penumbra_sdk_txhash::TransactionContext;
+
+use crate::liquidity_tournament::{
+    proof::LiquidityTournamentVoteProofPublic, ActionLiquidityTournamentVote,
+    LiquidityTournamentVoteBody, LIQUIDITY_TOURNAMENT_VOTE_DENOM_MAX_BYTES,
+};
+use cnidarium_component::ActionHandler;
+
+fn is_valid_denom(denom: &Denom) -> anyhow::Result<()> {
+    anyhow::ensure!(
+        denom.denom.len() <= LIQUIDITY_TOURNAMENT_VOTE_DENOM_MAX_BYTES,
+        "denom {} is not <= (MAX OF) {}",
+        &denom.denom,
+        LIQUIDITY_TOURNAMENT_VOTE_DENOM_MAX_BYTES
+    );
+    anyhow::ensure!(
+        denom.denom.starts_with("transfer/"),
+        "denom {} is not an IBC transfer asset",
+        &denom.denom
+    );
+    Ok(())
+}
+
+#[async_trait]
+impl ActionHandler for ActionLiquidityTournamentVote {
+    type CheckStatelessContext = TransactionContext;
+
+    async fn check_stateless(&self, context: TransactionContext) -> anyhow::Result<()> {
+        let Self {
+            auth_sig,
+            proof,
+            body:
+                LiquidityTournamentVoteBody {
+                    start_position,
+                    nullifier,
+                    rk,
+                    value,
+                    incentivized,
+                    ..
+                },
+        } = self;
+        // 1. Is it ok to vote on this denom?
+        is_valid_denom(incentivized)?;
+        // 2. Check spend auth signature using provided spend auth key.
+        rk.verify(context.effect_hash.as_ref(), auth_sig)
+            .with_context(|| {
+                format!(
+                    "{} auth signature failed to verify",
+                    std::any::type_name::<Self>()
+                )
+            })?;
+
+        // 3. Verify the proof against the provided anchor and start position:
+        let public = LiquidityTournamentVoteProofPublic {
+            anchor: context.anchor,
+            value: *value,
+            nullifier: *nullifier,
+            rk: *rk,
+            start_position: *start_position,
+        };
+        proof
+            .verify(&DELEGATOR_VOTE_PROOF_VERIFICATION_KEY, public)
+            .context("a LiquidityTournamentVote proof did not verify")?;
+
+        Ok(())
+    }
+
+    async fn check_and_execute<S: StateWrite>(&self, _state: S) -> anyhow::Result<()> {
+        todo!()
+    }
+}
diff --git a/crates/core/component/funding/src/action_handler/mod.rs b/crates/core/component/funding/src/action_handler/mod.rs
new file mode 100644
index 0000000000..0a22bdcd17
--- /dev/null
+++ b/crates/core/component/funding/src/action_handler/mod.rs
@@ -0,0 +1 @@
+pub mod liquidity_tournament;
diff --git a/crates/core/component/funding/src/lib.rs b/crates/core/component/funding/src/lib.rs
index 83d154c5d5..6e11248cf4 100644
--- a/crates/core/component/funding/src/lib.rs
+++ b/crates/core/component/funding/src/lib.rs
@@ -1,6 +1,8 @@
 #![deny(clippy::unwrap_used)]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #[cfg(feature = "component")]
+pub mod action_handler;
+#[cfg(feature = "component")]
 pub mod component;
 pub mod event;