feat - add token manager utility

src/main.rs

@@ -8,6 +8,7 @@ pub mod bot;
 pub mod cli;
 pub mod config;
 pub mod provider;
+pub mod token_manager;
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn Error>> {

src/token_manager.rs

@@ -0,0 +1,52 @@
+use crate::provider::SignerProvider;
+use alloy::providers::Provider;
+use alloy::sol;
+use alloy::transports::BoxTransport;
+use alloy_primitives::Address;
+use std::collections::HashMap;
+use std::error::Error;
+use std::sync::{Arc, Mutex};
+use IERC20::IERC20Instance;
+
+sol! {
+    #[derive(Debug, PartialEq, Eq)]
+    #[sol(rpc)]
+    contract IERC20 {
+        function decimals() external view returns (uint8);
+        function approve(address spender, uint256 amount) external returns (bool);
+        function balanceOf(address account) external view returns (uint256);
+        function transfer(address recipient, uint256 amount) external returns (bool);
+        function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
+    }
+}
+
+type Token = IERC20Instance<BoxTransport, Arc<SignerProvider>>;
+
+pub struct TokenManager {
+    tokens: Mutex<HashMap<Address, Token>>,
+    provider: Arc<SignerProvider>,
+}
+
+impl TokenManager {
+    pub fn new(provider: Arc<SignerProvider>) -> Self {
+        TokenManager {
+            tokens: Mutex::new(HashMap::new()),
+            provider,
+        }
+    }
+
+    pub fn get(&self, address: Address) -> Result<Token, Box<dyn Error>> {
+        let mut tokens = self
+            .tokens
+            .lock()
+            .map_err(|e| format!("Failed to acquire lock: {}", e))?;
+
+        if let Some(token) = tokens.get(&address) {
+            Ok(token.clone())
+        } else {
+            let new_token = IERC20::new(address, self.provider.clone());
+            tokens.insert(address, new_token.clone());
+            Ok(new_token)
+        }
+    }
+}