From b5b3ba5f44f76e2d7a7099c724c19cc3a8965039 Mon Sep 17 00:00:00 2001
From: Warren He <w@oasislabs.com>
Date: Fri, 11 Mar 2022 12:56:30 -0800
Subject: [PATCH] modules/consensus_accounts: handle incoming message tokens

---
 runtime-sdk/src/modules/accounts/mod.rs       | 20 +++++++++
 .../src/modules/consensus_accounts/mod.rs     | 44 ++++++++++++++++++-
 runtime-sdk/src/types/address.rs              |  6 +++
 3 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/runtime-sdk/src/modules/accounts/mod.rs b/runtime-sdk/src/modules/accounts/mod.rs
index bda154829b..bb69f7ef70 100644
--- a/runtime-sdk/src/modules/accounts/mod.rs
+++ b/runtime-sdk/src/modules/accounts/mod.rs
@@ -212,6 +212,11 @@ pub trait API {
         amount: &token::BaseUnits,
     ) -> Result<(), modules::core::Error>;
 
+    fn mint_into_fee_accumulator<C: Context>(
+        ctx: &mut C,
+        amount: &token::BaseUnits,
+    ) -> Result<(), modules::core::Error>;
+
     /// Move amount from fee accumulator into address.
     fn move_from_fee_accumulator<C: Context>(
         ctx: &mut C,
@@ -587,6 +592,21 @@ impl API for Module {
         Ok(())
     }
 
+    fn mint_into_fee_accumulator<C: Context>(
+        ctx: &mut C,
+        amount: &token::BaseUnits,
+    ) -> Result<(), modules::core::Error> {
+        if ctx.is_simulation() {
+            return Ok(());
+        }
+
+        ctx.value::<FeeAccumulator>(CONTEXT_KEY_FEE_ACCUMULATOR)
+            .or_default()
+            .add(amount);
+
+        Ok(())
+    }
+
     fn move_from_fee_accumulator<C: Context>(
         ctx: &mut C,
         to: Address,
diff --git a/runtime-sdk/src/modules/consensus_accounts/mod.rs b/runtime-sdk/src/modules/consensus_accounts/mod.rs
index f16ce0c711..c0c95209db 100644
--- a/runtime-sdk/src/modules/consensus_accounts/mod.rs
+++ b/runtime-sdk/src/modules/consensus_accounts/mod.rs
@@ -4,10 +4,16 @@
 //! while keeping track of amount deposited per account.
 use std::{collections::BTreeSet, convert::TryInto};
 
+use num_traits::Zero;
 use once_cell::sync::Lazy;
 use thiserror::Error;
 
-use oasis_core_runtime::consensus::staking::Account as ConsensusAccount;
+use oasis_core_runtime::{
+    consensus::{
+        staking::Account as ConsensusAccount,
+        roothash,
+    },
+};
 use oasis_runtime_sdk_macros::{handler, sdk_derive};
 
 use crate::{
@@ -20,9 +26,10 @@ use crate::{
     storage::Prefix,
     types::{
         address::Address,
+        in_msg::IncomingMessageData,
         message::{MessageEvent, MessageEventHookInvocation},
         token,
-        transaction::AuthInfo,
+        transaction::{AuthInfo, Transaction},
     },
 };
 
@@ -416,6 +423,39 @@ impl<Accounts: modules::accounts::API, Consensus: modules::consensus::API>
 {
 }
 
+impl<Accounts: modules::accounts::API, Consensus: modules::consensus::API>
+    module::IncomingMessageHandler for Module<Accounts, Consensus>
+{
+    fn prefetch_in_msg(
+        _prefixes: &mut BTreeSet<Prefix>,
+        _in_msg: &roothash::IncomingMessage,
+        _data: &IncomingMessageData,
+        _tx: &Option<Transaction>,
+    ) -> Result<(), error::RuntimeError> {
+        // todo: their account
+        Ok(())
+    }
+
+    fn execute_in_msg<C: Context>(
+        ctx: &mut C,
+        in_msg: &roothash::IncomingMessage,
+        _data: &IncomingMessageData,
+        _tx: &Option<Transaction>,
+    ) -> Result<(), error::RuntimeError> {
+        if !in_msg.fee.is_zero() {
+            let amount = token::BaseUnits(Consensus::amount_from_consensus(ctx, (&in_msg.fee).try_into().unwrap()).unwrap(), Consensus::consensus_denomination(ctx).unwrap());
+            Accounts::mint_into_fee_accumulator(ctx, &amount).unwrap();
+            // TODO: Emit event that fee has been paid.
+        }
+        if !in_msg.tokens.is_zero() {
+            let amount = token::BaseUnits(Consensus::amount_from_consensus(ctx, (&in_msg.tokens).try_into().unwrap()).unwrap(), Consensus::consensus_denomination(ctx).unwrap());
+            Accounts::mint(ctx, (&in_msg.caller).into(), &amount).unwrap();
+            // TODO: Emit event.
+        }
+        Ok(())
+    }
+}
+
 impl<Accounts: modules::accounts::API, Consensus: modules::consensus::API> module::BlockHandler
     for Module<Accounts, Consensus>
 {
diff --git a/runtime-sdk/src/types/address.rs b/runtime-sdk/src/types/address.rs
index d4ff0a340f..09e6be284b 100644
--- a/runtime-sdk/src/types/address.rs
+++ b/runtime-sdk/src/types/address.rs
@@ -250,6 +250,12 @@ impl From<Address> for ConsensusAddress {
     }
 }
 
+impl From<&ConsensusAddress> for Address {
+    fn from(addr: &ConsensusAddress) -> Address {
+        Address::from_bytes(addr.as_ref()).unwrap()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;