refactor(bridge): improve types/traits

This is based on the discussion in PR
[#230](#230)

Author: Rajil1213

bin/bridge-client/src/modes/operator/constants.rs renamed to bin/bridge-client/src/constants.rs

@@ -4,7 +4,9 @@
 //! publishing appropriate transactions. Can also perform challenger duties.
 
 mod args;
+pub(crate) mod constants;
 mod modes;
+pub(crate) mod rpc_server;
 
 use alpen_express_common::logging;
 use args::{Args, ModeOfOperation};
@@ -20,11 +22,14 @@ async fn main() {
 
     info!("running bridge client in {} mode", cli_args.mode);
 
-    if let ModeOfOperation::Operator = cli_args.mode {
-        operator::bootstrap()
-            .await
-            .expect("bootstrap operator node");
-    } else {
-        challenger::bootstrap().await;
+    match cli_args.mode {
+        ModeOfOperation::Operator => {
+            operator::bootstrap()
+                .await
+                .expect("bootstrap operator node");
+        }
+        ModeOfOperation::Challenger => {
+            challenger::bootstrap().await;
+        }
     }
 }

bin/bridge-client/src/main.rs

@@ -1,8 +1,6 @@
 //! Defines the main loop for the bridge-client in operator mode.
-mod constants;
-mod rpc_server;
 
-use rpc_server::BridgeRpcImpl;
+use crate::rpc_server::{self, BridgeRpcImpl};
 
 /// Bootstraps the bridge client in Operator mode by hooking up all the required auxiliary services
 /// including database, rpc server, etc. Threadpool and logging need to be initialized at the call

bin/bridge-client/src/modes/operator/mod.rs

@@ -6,9 +6,10 @@ use jsonrpsee::{core::RpcResult, RpcModule};
 use tokio::sync::oneshot;
 use tracing::{info, warn};
 
-use super::constants::{RPC_PORT, RPC_SERVER};
 use express_bridge_rpc_api::{ExpressBridgeControlApiServer, ExpressBridgeNetworkApiServer};
 
+use crate::constants::{RPC_PORT, RPC_SERVER};
+
 pub(crate) async fn start<T>(rpc_impl: &T) -> anyhow::Result<()>
 where
     T: ExpressBridgeControlApiServer + ExpressBridgeNetworkApiServer + Clone,

bin/bridge-client/src/modes/operator/rpc_server.rs renamed to bin/bridge-client/src/rpc_server.rs

@@ -4,4 +4,3 @@
 
 pub mod checkpoint;
 pub mod errors;
-pub mod report_status;

crates/bridge-exec/src/book_keeping/mod.rs

@@ -39,7 +39,7 @@ pub struct AddressConfig {
 
 impl Config {
     /// Parse the config at the given path and produce the [`Config`].
-    pub fn from_path(path: &PathBuf) -> ParseConfigResult<Self> {
+    pub fn load_from_path(path: &PathBuf) -> InitResult<Self> {
         let contents = fs::read_to_string(path)?;
         let config = toml::from_str::<Config>(contents.as_str())
             .map_err(|e| SerdeError::new(contents, e))?;
@@ -59,9 +59,10 @@ pub struct SecretsConfig {
     pub_key: PathBuf,
 }
 
-/// Error with the configuration.
+/// Error during initialization.
+// TODO: move this out to a dedicated module or `bin`.
 #[derive(Debug, Error)]
-pub enum ConfigError {
+pub enum InitError {
     /// I/O related error while reading config.
     #[error("error loading config file: {0}")]
     Io(#[from] io::Error),
@@ -72,4 +73,4 @@ pub enum ConfigError {
 }
 
 /// Result of parsing the config file which may produce a [`ConfigError`].
-pub type ParseConfigResult<T> = Result<T, ConfigError>;
+pub type InitResult<T> = Result<T, InitError>;

crates/bridge-exec/src/book_keeping/report_status.rs

@@ -1,34 +1,46 @@
 //! Defines the traits that encapsulates all functionalities that pertain to handling a deposit.
 
+use std::sync::Arc;
+
 use async_trait::async_trait;
 use bitcoin::secp256k1::schnorr::Signature;
 
-use express_bridge_txm::{DepositInfo, DepositRequest, SignatureInfo};
+use alpen_express_rpc_api::AlpenBridgeApiClient;
+use express_bridge_txm::{DepositInfo, DepositRequest, Signed, Unsigned};
 
-use crate::book_keeping::{checkpoint::ManageCheckpoint, report_status::ReportStatus};
+use crate::book_keeping::checkpoint::ManageCheckpoint;
 
 use super::errors::DepositExecResult;
 
+/// Holds the context and methods to handle deposit processing.
+#[derive(Debug, Clone)]
+pub struct DepositHandler<Api: AlpenBridgeApiClient> {
+    /// The RPC client to communicate with the rollup node for broadcasting messages.
+    pub rpc_client: Arc<Api>,
+    // add other useful sfuff such as a database handle.
+}
+
 /// Defines the ability to process deposits.
 #[async_trait]
-pub trait HandleDeposit: ManageCheckpoint + ReportStatus + Clone + Send + Sync + Sized {
+pub trait HandleDeposit: ManageCheckpoint + Clone + Send + Sync + Sized {
     /// Construct and sign the deposit transaction.
-    async fn sign_deposit_tx(&self, deposit_info: &DepositInfo)
-        -> DepositExecResult<SignatureInfo>;
+    async fn sign_deposit_tx(
+        &self,
+        deposit_request: &DepositRequest<Unsigned>,
+    ) -> DepositExecResult<DepositRequest<Signed>>;
 
     /// Add the signature to the already accumulated set of signatures for a deposit transaction and
     /// produce the aggregated signature if all operators have signed. Also update the database
     /// entry with the signatures accumulated so far.
     async fn aggregate_signature(
         &self,
-        deposit_request: &DepositRequest,
+        deposit_request: &DepositRequest<Signed>,
     ) -> DepositExecResult<Option<Signature>>;
 
     /// Broadcast the signature to the rest of the bridge operator clients.
     async fn broadcast_partial_deposit_sig(
         &self,
-        deposit_info: &DepositInfo,
-        sig: &SignatureInfo,
+        deposit_request: &DepositRequest<Signed>,
     ) -> DepositExecResult<()>;
 
     /// Broadcast the fully signed deposit transaction to the bitcoin p2p (via a full node).

crates/bridge-exec/src/config.rs

@@ -7,5 +7,4 @@ pub mod book_keeping;
 pub mod challenger;
 pub mod config;
 pub mod deposit_handler;
-pub mod operator;
 pub mod withdrawal_handler;