shielded_token/vp: replace IBC dep with DI

crates/core/src/ibc.rs

@@ -1,16 +1,70 @@
 //! IBC-related data types
 
+use std::collections::{BTreeMap, BTreeSet};
 use std::str::FromStr;
 
 use borsh::{BorshDeserialize, BorshSchema, BorshSerialize};
 use data_encoding::{DecodePartial, HEXLOWER, HEXLOWER_PERMISSIVE};
+use ibc::core::host::types::identifiers::{ChannelId, PortId, Sequence};
 pub use ibc::*;
+use masp_primitives::transaction::components::ValueSum;
+use masp_primitives::transaction::TransparentAddress;
 use namada_macros::BorshDeserializer;
 #[cfg(feature = "migrations")]
 use namada_migrations::*;
 use serde::{Deserialize, Serialize};
 
 use super::address::HASH_LEN;
+use crate::address::Address;
+use crate::masp::TAddrData;
+use crate::{storage, token};
+
+/// Abstract IBC storage keys
+pub trait Keys {
+    /// Returns a key for the receipt
+    fn receipt_key(
+        port_id: &PortId,
+        channel_id: &ChannelId,
+        sequence: Sequence,
+    ) -> storage::Key;
+
+    /// Returns a key for the ack
+    fn ack_key(
+        port_id: &PortId,
+        channel_id: &ChannelId,
+        sequence: Sequence,
+    ) -> storage::Key;
+}
+
+/// Abstract IBC storage read interface
+pub trait Read<S> {
+    /// Storage error
+    type Err;
+
+    /// Extract MASP transaction from IBC envelope
+    fn try_extract_masp_tx_from_envelope(
+        tx_data: &[u8],
+    ) -> Result<Option<masp_primitives::transaction::Transaction>, Self::Err>;
+
+    /// Apply relevant IBC packets to the changed balances structure
+    fn apply_ibc_packet(
+        storage: &S,
+        tx_data: &[u8],
+        acc: ChangedBalances,
+        keys_changed: &BTreeSet<storage::Key>,
+    ) -> Result<ChangedBalances, Self::Err>;
+}
+
+/// Balances changed by a transaction
+#[derive(Default, Debug, Clone)]
+pub struct ChangedBalances {
+    /// Map between MASP transparent address and namada types
+    pub decoder: BTreeMap<TransparentAddress, TAddrData>,
+    /// Balances before the tx
+    pub pre: BTreeMap<TransparentAddress, ValueSum<Address, token::Amount>>,
+    /// Balances after the tx
+    pub post: BTreeMap<TransparentAddress, ValueSum<Address, token::Amount>>,
+}
 
 /// IBC token hash derived from a denomination.
 #[derive(