src/web3/base_tx.rs

use anyhow::Result;
use alloy::{
    network::TransactionBuilder,
    primitives::U256,
    providers::{Provider, ProviderBuilder},
    signers::local::PrivateKeySigner,
    rpc::types::TransactionRequest,
};
use std::str::FromStr;

pub async fn commit_cid(cid: &str) -> Result<String> {
    let rpc_url = "https://sepolia.base.org".parse()?;

    let priv_key = std::env::var("PRIVATE_KEY")
        .unwrap_or_else(|_| "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80".to_string());

    let signer = PrivateKeySigner::from_str(&priv_key)?;
    let from = signer.address();
    let wallet = alloy::network::EthereumWallet::from(signer);

    let provider = ProviderBuilder::new()
        .wallet(wallet)
        .on_http(rpc_url);

    let data = cid.as_bytes().to_vec();

    let mut tx = TransactionRequest::default()
        .with_from(from)
        .with_to(from)       // self‑transfer
        .with_value(U256::ZERO)
        .with_input(data)
        .with_chain_id(84532);   // <-- Base Sepolia chain ID

    let nonce = provider.get_transaction_count(from).await?;
    let gas_limit = provider.estimate_gas(&tx).await?;
    let fee = provider.estimate_eip1559_fees(None).await?;

    tx = tx
        .with_nonce(nonce)
        .with_gas_limit(gas_limit)
        .with_max_fee_per_gas(fee.max_fee_per_gas)
        .with_max_priority_fee_per_gas(fee.max_priority_fee_per_gas);

    // Retry loop (handles 502 errors)
    let mut attempts = 0;
    loop {
        match provider.send_transaction(tx.clone()).await {
            Ok(pending) => {
                let receipt = pending.get_receipt().await?;
                let tx_hash = receipt.transaction_hash;
                tracing::info!(
                    "Committed CID {} to Base Sepolia, tx: {:?}",
                    cid,
                    tx_hash
                );
                return Ok(format!("{:?}", tx_hash));
            }
            Err(e) if attempts < 3 && e.to_string().contains("502") => {
                attempts += 1;
                tokio::time::sleep(std::time::Duration::from_secs(2)).await;
                continue;
            }
            Err(e) => return Err(anyhow::Error::new(e).context("send_transaction failed")),
        }
    }
}