kora-lib 2.0.5

#[cfg(not(test))]
use crate::state::get_config;
#[cfg(test)]
use crate::tests::config_mock::mock_state::get_config;
use crate::{cache::CacheUtil, error::KoraError, state::get_signers_info};
use prometheus::{register_gauge_vec, GaugeVec};
use solana_client::nonblocking::rpc_client::RpcClient;
use solana_sdk::pubkey::Pubkey;
use std::{str::FromStr, sync::Arc};
use tokio::{
    sync::OnceCell,
    task::JoinHandle,
    time::{interval, Duration},
};

/// Global Prometheus gauge vector for tracking all signer balances
static SIGNER_BALANCE_GAUGES: OnceCell<GaugeVec> = OnceCell::const_new();

/// Balance tracker for monitoring signer SOL balance
pub struct BalanceTracker;

impl BalanceTracker {
    /// Initialize the Prometheus gauge vector for multi-signer balance tracking
    pub async fn init() -> Result<(), KoraError> {
        if !BalanceTracker::is_enabled() {
            return Ok(());
        }

        let gauge_vec = register_gauge_vec!(
            "signer_balance_lamports",
            "Current SOL balance of each signer in lamports",
            &["signer_name", "signer_pubkey"]
        )
        .map_err(|e| {
            KoraError::InternalServerError(format!("Failed to register balance gauge vector: {e}"))
        })?;

        SIGNER_BALANCE_GAUGES.set(gauge_vec).map_err(|_| {
            KoraError::InternalServerError("Balance gauge vector already initialized".to_string())
        })?;

        log::info!("Multi-signer balance tracking metrics initialized");
        Ok(())
    }

    /// Track all signers' balances and update Prometheus metrics
    pub async fn track_all_signer_balances(rpc_client: &Arc<RpcClient>) -> Result<(), KoraError> {
        if !BalanceTracker::is_enabled() {
            return Ok(());
        }

        // Get all signers in the pool
        let signers_info = get_signers_info()?;

        if let Some(gauge_vec) = SIGNER_BALANCE_GAUGES.get() {
            let mut balance_results = Vec::new();

            // Batch fetch all signer balances
            for signer_info in &signers_info {
                let pubkey = Pubkey::from_str(&signer_info.public_key).map_err(|e| {
                    KoraError::InternalServerError(format!(
                        "Invalid signer pubkey {}: {e}",
                        signer_info.public_key
                    ))
                })?;

                match CacheUtil::get_account(rpc_client, &pubkey, false).await {
                    Ok(account) => {
                        balance_results.push((signer_info, account.lamports));
                    }
                    Err(e) => {
                        log::warn!(
                            "Failed to get balance for signer {} ({}): {e}",
                            signer_info.name,
                            signer_info.public_key
                        );
                        // Set balance to 0 on error to indicate issue
                        balance_results.push((signer_info, 0));
                    }
                }
            }

            // Update all gauge metrics
            for (signer_info, balance_lamports) in balance_results {
                let gauge =
                    gauge_vec.with_label_values(&[&signer_info.name, &signer_info.public_key]);

                gauge.set(balance_lamports as f64);

                log::debug!(
                    "Updated balance metrics: {} lamports for signer {} ({})",
                    balance_lamports,
                    signer_info.name,
                    signer_info.public_key
                );
            }
        } else {
            log::warn!("Balance gauge vector not initialized, skipping metrics update");
        }

        Ok(())
    }

    /// Start a background task that tracks balance at regular intervals
    /// Returns a JoinHandle to allow for proper task shutdown
    pub async fn start_background_tracking(rpc_client: Arc<RpcClient>) -> Option<JoinHandle<()>> {
        if !BalanceTracker::is_enabled() {
            log::info!("Balance tracking is disabled, not starting background task");
            return None;
        }

        let config = match get_config() {
            Ok(config) => config,
            Err(e) => {
                log::error!("Failed to get config for balance tracking: {e}");
                return None;
            }
        };

        let interval_seconds = config.metrics.fee_payer_balance.expiry_seconds;
        log::info!("Starting multi-signer balance tracking background task with {interval_seconds}s interval");

        // Spawn a background task that runs forever
        let handle = tokio::spawn(async move {
            let mut interval = interval(Duration::from_secs(interval_seconds));

            loop {
                interval.tick().await;

                // Track all signer balances, but don't let errors crash the loop
                if let Err(e) = BalanceTracker::track_all_signer_balances(&rpc_client).await {
                    log::warn!("Failed to track signer balances in background task: {e}");
                }
            }
        });

        Some(handle)
    }

    pub fn is_enabled() -> bool {
        match get_config() {
            Ok(config) => config.metrics.enabled && config.metrics.fee_payer_balance.enabled,
            Err(_) => false,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{
        config::FeePayerBalanceMetricsConfig,
        signer::{pool::SignerWithMetadata, SignerPool},
        state::update_signer_pool,
        tests::{
            account_mock::create_mock_account_with_balance,
            common::RpcMockBuilder,
            config_mock::{ConfigMockBuilder, MetricsConfigBuilder},
        },
    };
    use solana_keychain::Signer;
    use solana_sdk::signature::Keypair;

    fn setup_test_signer_pool() {
        let keypair1 = Keypair::new();
        let keypair2 = Keypair::new();

        let external_signer1 = Signer::from_memory(&keypair1.to_base58_string()).unwrap();
        let external_signer2 = Signer::from_memory(&keypair2.to_base58_string()).unwrap();

        let pool = SignerPool::new(vec![
            SignerWithMetadata::new("signer_1".to_string(), Arc::new(external_signer1), 1),
            SignerWithMetadata::new("signer_2".to_string(), Arc::new(external_signer2), 2),
        ]);

        let _ = update_signer_pool(pool);
    }

    #[tokio::test]
    async fn test_is_enabled_when_disabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(false)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: false,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        assert!(!BalanceTracker::is_enabled());
    }

    #[tokio::test]
    async fn test_is_enabled_when_enabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(true)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: true,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        assert!(BalanceTracker::is_enabled());
    }

    #[tokio::test]
    async fn test_is_enabled_requires_both_flags() {
        // Test case: metrics enabled but balance metrics disabled
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(true)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: false,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        assert!(!BalanceTracker::is_enabled());
    }

    #[tokio::test]
    async fn test_is_enabled_metrics_disabled_balance_enabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(false)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: true,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        assert!(!BalanceTracker::is_enabled());
    }

    #[tokio::test]
    async fn test_init_when_disabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(false)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: false,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        let result = BalanceTracker::init().await;
        assert!(result.is_ok());
    }

    #[tokio::test]
    async fn test_init_when_enabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(true)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: true,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        let result = BalanceTracker::init().await;
        assert!(result.is_ok());
    }

    #[tokio::test]
    async fn test_track_all_signer_balances_when_disabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(false)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: false,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        let mock_rpc = RpcMockBuilder::new().build();
        let result = BalanceTracker::track_all_signer_balances(&mock_rpc).await;
        assert!(result.is_ok());
    }

    #[tokio::test]
    async fn test_track_all_signer_balances_successful() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(true)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: true,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        setup_test_signer_pool();
        let _ = BalanceTracker::init().await;

        let account = create_mock_account_with_balance(1_000_000_000); // 1 SOL
        let mock_rpc = RpcMockBuilder::new().with_account_info(&account).build();

        let result = BalanceTracker::track_all_signer_balances(&mock_rpc).await;
        assert!(result.is_ok());
    }

    #[tokio::test]
    async fn test_track_all_signer_balances_handles_rpc_errors() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(true)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: true,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        setup_test_signer_pool();
        let _ = BalanceTracker::init().await;

        let mock_rpc = RpcMockBuilder::new().with_account_not_found().build();

        let result = BalanceTracker::track_all_signer_balances(&mock_rpc).await;
        assert!(result.is_ok());
    }

    #[tokio::test]
    async fn test_start_background_tracking_when_disabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(false)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: false,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        let mock_rpc = RpcMockBuilder::new().build();
        let handle = BalanceTracker::start_background_tracking(mock_rpc).await;

        assert!(handle.is_none());
    }

    #[tokio::test]
    async fn test_start_background_tracking_when_enabled() {
        let _m = ConfigMockBuilder::new()
            .with_metrics(
                MetricsConfigBuilder::new()
                    .with_enabled(true)
                    .with_fee_payer_balance(FeePayerBalanceMetricsConfig {
                        enabled: true,
                        expiry_seconds: 30,
                    })
                    .build(),
            )
            .build_and_setup();

        setup_test_signer_pool();
        let _ = BalanceTracker::init().await;

        let mock_rpc = RpcMockBuilder::new().build();
        let handle = BalanceTracker::start_background_tracking(mock_rpc).await;

        assert!(handle.is_some());

        if let Some(task) = handle {
            task.abort();
        }
    }
}