From a83e42aff05db12b478c884514349b136ea787b0 Mon Sep 17 00:00:00 2001
From: yihao <zuoanyg@qq.com>
Date: Sat, 12 Aug 2023 22:10:39 -0700
Subject: [PATCH] [Chain Utils] Add chain_utils module and implement
 get_inception_block.

---
 bot/crates/strategy/Cargo.toml                |  1 +
 bot/crates/strategy/src/common/chain_utils.rs | 76 +++++++++++++++++++
 bot/crates/strategy/src/common/mod.rs         |  1 +
 bot/crates/strategy/src/lib.rs                |  3 +
 4 files changed, 81 insertions(+)
 create mode 100644 bot/crates/strategy/src/common/chain_utils.rs
 create mode 100644 bot/crates/strategy/src/common/mod.rs

diff --git a/bot/crates/strategy/Cargo.toml b/bot/crates/strategy/Cargo.toml
index e0c609a..e2c43b2 100644
--- a/bot/crates/strategy/Cargo.toml
+++ b/bot/crates/strategy/Cargo.toml
@@ -32,6 +32,7 @@ artemis-core = { path = "../artemis-core" }
 
 [dev-dependencies]
 fern = {version = "0.6.2", features = ["colored"]}
+env_logger = "0.10.0"
 
 [features]
 debug = []
diff --git a/bot/crates/strategy/src/common/chain_utils.rs b/bot/crates/strategy/src/common/chain_utils.rs
new file mode 100644
index 0000000..56b3776
--- /dev/null
+++ b/bot/crates/strategy/src/common/chain_utils.rs
@@ -0,0 +1,76 @@
+use ethers::{
+    providers::{Middleware, ProviderError},
+    types::{BlockNumber, Address, U64, NameOrAddress, BlockId}
+};
+use log::{info, debug};
+use std::sync::Arc;
+
+pub async fn get_inception_block<M: Middleware>(
+    contract: Address,
+    provider: Arc<M>) -> Result<BlockNumber, ProviderError>
+{
+    let mut last_block =
+        provider.get_block_number().await
+                .map_err(|err| ProviderError::CustomError(err.to_string()))?;
+
+        // I am very confused about how to do the pattern matching here because provide_err is a reference
+        // to ProviderError.
+        //    |err| match err.as_provider_error() {
+        //        Some(provider_err) => ProviderError::from_err(provider_err),
+        //        _ => ProviderError::CustomError(err.to_string())
+        //    };
+
+    let mut start_block = U64([1]);
+    let mut rpc_count = 0;
+
+    while start_block < last_block {
+        let mid_block = start_block + (last_block - start_block) / 2;
+        let code =
+            provider.get_code(
+                NameOrAddress::Address(contract),
+                Some(BlockId::Number(BlockNumber::Number(mid_block))))
+                .await;
+        rpc_count += 1;
+        debug!("Searching ({}) at block {:?} (start: {:?}, last: {:?}).",
+               rpc_count, mid_block, start_block, last_block);
+        match code {
+            Ok(_) => {
+                info!("Successfully find the code of contract {:?}, block {:?}.", contract, mid_block);
+                last_block = mid_block;
+            },
+            Err(e) => {
+                info!("Failed to find the code of contract {:?}, block {:?}, err({:?}).", contract, mid_block, e);
+                start_block = mid_block + 1;
+            }
+        }
+    }
+    return Ok(BlockNumber::Number(start_block));
+}
+
+#[cfg(test)]
+mod tests {
+    use std::error::Error;
+    use std::str::FromStr;
+    use ethers::providers::{Provider, Ws};
+    use env_logger;
+    use super::*;
+
+    // For some reason, the url below couldn't fetch code from the last 128 blocks.
+    // So that we cannot use the binary search to find the contract creation block.
+    // More details see https://ethereum.stackexchange.com/questions/40648/full-node-sync-only-preserve-the-last-128-history-states.
+    // In short, the current get_inception_block only works in the archive node.
+
+    #[tokio::test]
+    async fn test_get_inception_block() -> Result<(), Box<dyn Error>>
+    {
+        env_logger::init();
+
+        let contract = Address::from_str("0x115934131916C8b277DD010Ee02de363c09d037c")?;
+        let url: &str =
+            "wss://capable-crimson-vineyard.discover.quiknode.pro/b0f808fe30ebe9dd7b2a7122c563e20f1e9966da/";
+        let provider = Arc::new(Provider::new(Ws::connect(url).await?));
+        let block = get_inception_block(contract, provider).await?;
+        assert_eq!(block.as_number().unwrap().as_u64(), 12771526u64);
+        return Ok(());
+    }
+}
\ No newline at end of file
diff --git a/bot/crates/strategy/src/common/mod.rs b/bot/crates/strategy/src/common/mod.rs
new file mode 100644
index 0000000..5b282f8
--- /dev/null
+++ b/bot/crates/strategy/src/common/mod.rs
@@ -0,0 +1 @@
+pub mod chain_utils;
\ No newline at end of file
diff --git a/bot/crates/strategy/src/lib.rs b/bot/crates/strategy/src/lib.rs
index 7de6c42..287731c 100644
--- a/bot/crates/strategy/src/lib.rs
+++ b/bot/crates/strategy/src/lib.rs
@@ -12,5 +12,8 @@ mod tx_utils;
 /// Module contains core strategy implementation
 pub mod bot;
 
+/// Modules contains common utilities
+pub mod common;
+
 /// Module contains the core type defenitions for sandwiching
 pub mod types;