feat: Add ChainId model

Remove to_chain_id helper method

--- don't change below this line ---
ENG-4081 Took 28 minutes

src/encoding/evm/approvals/permit2.rs

@@ -1,7 +1,7 @@
 use std::{str::FromStr, sync::Arc};
 
 use alloy::{
-    primitives::{aliases::U48, Address, Bytes as AlloyBytes, ChainId, TxKind, U160, U256},
+    primitives::{aliases::U48, Address, Bytes as AlloyBytes, TxKind, U160, U256},
     providers::{Provider, RootProvider},
     rpc::types::{TransactionInput, TransactionRequest},
     signers::{local::PrivateKeySigner, SignerSync},
@@ -20,7 +20,8 @@ use crate::encoding::{
     errors::EncodingError,
     evm::{
         approvals::protocol_approvals_manager::get_client,
-        utils::{biguint_to_u256, bytes_to_address, encode_input, to_chain_id},
+        models::ChainId,
+        utils::{biguint_to_u256, bytes_to_address, encode_input},
     },
 };
 
@@ -62,7 +63,7 @@ sol! {
 #[allow(dead_code)]
 impl Permit2 {
     pub fn new(signer_pk: String, chain: Chain) -> Result<Self, EncodingError> {
-        let chain_id = to_chain_id(chain)?;
+        let chain_id = ChainId::from(chain);
         let runtime = Runtime::new()
             .map_err(|_| EncodingError::FatalError("Failed to create runtime".to_string()))?;
         let client = runtime.block_on(get_client())?;
@@ -145,7 +146,7 @@ impl Permit2 {
 
         let domain = eip712_domain! {
             name: "Permit2",
-            chain_id: self.chain_id,
+            chain_id: self.chain_id.id(),
             verifying_contract: self.address,
         };
         let hash = permit_single.eip712_signing_hash(&domain);

src/encoding/evm/mod.rs

@@ -1,4 +1,5 @@
 pub mod approvals;
+mod models;
 mod router_encoder;
 mod strategy_encoder;
 mod swap_encoder;

src/encoding/evm/models.rs

@@ -0,0 +1,20 @@
+use tycho_core::models::Chain;
+
+pub struct ChainId(u64);
+
+impl ChainId {
+    pub fn id(&self) -> u64 {
+        self.0
+    }
+}
+
+impl From<Chain> for ChainId {
+    fn from(chain: Chain) -> Self {
+        match chain {
+            Chain::Ethereum => ChainId(1),
+            Chain::ZkSync => ChainId(324),
+            Chain::Arbitrum => ChainId(42161),
+            Chain::Starknet => ChainId(0),
+        }
+    }
+}

src/encoding/evm/utils.rs

@@ -1,7 +1,7 @@
 use alloy_primitives::{aliases::U24, Address, Keccak256, U256};
 use alloy_sol_types::SolValue;
 use num_bigint::BigUint;
-use tycho_core::{models::Chain, Bytes};
+use tycho_core::Bytes;
 
 use crate::encoding::errors::EncodingError;
 
@@ -65,10 +65,3 @@ pub fn percentage_to_uint24(percentage: f64) -> U24 {
     let scaled = (percentage / 100.0) * (MAX_UINT24 as f64);
     U24::from(scaled.round())
 }
-
-pub fn to_chain_id(chain: Chain) -> Result<u64, EncodingError> {
-    match chain {
-        Chain::Ethereum => Ok(1),
-        _ => Err(EncodingError::FatalError("Unsupported chain".to_string())),
-    }
-}