cdk-mintd 0.18.0

#[cfg(feature = "fakewallet")]
use std::collections::HashMap;
#[cfg(feature = "fakewallet")]
use std::collections::HashSet;
use std::path::Path;
#[cfg(any(feature = "grpc-processor", feature = "ldk-node"))]
use std::path::PathBuf;
use std::sync::Arc;
#[cfg(feature = "bdk")]
use std::time::Duration;

use async_trait::async_trait;
#[cfg(feature = "fakewallet")]
use bip39::rand::{thread_rng, Rng};
use cdk::cdk_database::KVStore;
use cdk::cdk_payment::MintPayment;
use cdk::nuts::CurrencyUnit;
#[cfg(any(
    feature = "cln",
    feature = "lnd",
    feature = "ldk-node",
    feature = "bdk",
    feature = "fakewallet"
))]
use cdk::types::FeeReserve;

use crate::config::{self, Settings};
#[cfg(feature = "cln")]
use crate::expand_path;

#[async_trait]
pub trait PaymentBackendSetup {
    async fn setup(
        &self,
        settings: &Settings,
        unit: CurrencyUnit,
        runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        work_dir: &Path,
        kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<impl MintPayment<Err = cdk_common::payment::Error>>;
}

#[async_trait]
pub trait OnchainBackendSetup {
    async fn setup(
        &self,
        settings: &Settings,
        unit: CurrencyUnit,
        runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        work_dir: &Path,
        kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<impl MintPayment<Err = cdk_common::payment::Error>>;
}

#[cfg(feature = "cln")]
#[async_trait]
impl PaymentBackendSetup for config::Cln {
    async fn setup(
        &self,
        _settings: &Settings,
        _unit: CurrencyUnit,
        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        _work_dir: &Path,
        kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<cdk_cln::Cln> {
        // Validate required connection field
        if self.rpc_path.as_os_str().is_empty() {
            return Err(anyhow::anyhow!(
                "CLN rpc_path must be set in [cln].rpc_path"
            ));
        }

        let cln_socket = expand_path(
            self.rpc_path
                .to_str()
                .ok_or(anyhow::anyhow!("cln socket not defined"))?,
        )
        .ok_or(anyhow::anyhow!("cln socket not defined"))?;

        let fee_reserve = FeeReserve {
            min_fee_reserve: self.reserve_fee_min,
            percent_fee_reserve: self.fee_percent,
        };

        let cln = cdk_cln::Cln::new(
            cln_socket,
            fee_reserve,
            self.expose_private_channels,
            kv_store.expect("Cln needs kv store"),
        )
        .await?
        .with_bolt12(self.bolt12);

        Ok(cln)
    }
}

#[cfg(feature = "lnd")]
#[async_trait]
impl PaymentBackendSetup for config::Lnd {
    async fn setup(
        &self,
        _settings: &Settings,
        _unit: CurrencyUnit,
        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        _work_dir: &Path,
        kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<cdk_lnd::Lnd> {
        use anyhow::bail;
        // Validate required connection fields
        if self.address.is_empty() {
            bail!("LND address must be set in [lnd].address");
        }
        if self.cert_file.as_os_str().is_empty() {
            bail!("LND cert_file must be set in [lnd].cert_file");
        }
        if self.macaroon_file.as_os_str().is_empty() {
            bail!("LND macaroon_file must be set in [lnd].macaroon_file");
        }

        let address = &self.address;
        let cert_file = &self.cert_file;
        let macaroon_file = &self.macaroon_file;

        let fee_reserve = FeeReserve {
            min_fee_reserve: self.reserve_fee_min,
            percent_fee_reserve: self.fee_percent,
        };

        let lnd = cdk_lnd::Lnd::new(
            address.to_string(),
            cert_file.clone(),
            macaroon_file.clone(),
            fee_reserve,
            kv_store.expect("Lnd needs kv store"),
        )
        .await?;

        Ok(lnd)
    }
}

#[cfg(feature = "fakewallet")]
#[async_trait]
impl PaymentBackendSetup for config::FakeWallet {
    async fn setup(
        &self,
        _settings: &Settings,
        unit: CurrencyUnit,
        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        _work_dir: &Path,
        _kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<cdk_fake_wallet::FakeWallet> {
        let fee_reserve = FeeReserve {
            min_fee_reserve: self.reserve_fee_min,
            percent_fee_reserve: self.fee_percent,
        };

        // calculate random delay time
        let mut rng = thread_rng();
        let delay_time = rng.gen_range(self.min_delay_time..=self.max_delay_time);

        let mut custom_payment_methods = HashMap::new();
        for custom_payment_method in &self.custom_payment_methods {
            if !custom_payment_method.applies_to_unit(&unit) {
                continue;
            }

            let method = custom_payment_method.method().trim().to_lowercase();
            if method.is_empty() {
                anyhow::bail!("Fake wallet custom payment method cannot be empty");
            }

            if matches!(method.as_str(), "bolt11" | "bolt12" | "onchain") {
                anyhow::bail!(
                    "Fake wallet custom payment method `{method}` conflicts with a known payment method"
                );
            }

            custom_payment_methods.insert(method, "{}".to_string());
        }

        let fake_wallet = cdk_fake_wallet::FakeWallet::new(
            fee_reserve,
            HashMap::default(),
            HashSet::default(),
            delay_time,
            unit,
        )
        .with_custom_payment_methods(custom_payment_methods);

        Ok(fake_wallet)
    }
}

#[cfg(all(test, feature = "fakewallet"))]
mod tests {
    use cdk::cdk_payment::MintPayment;

    use super::*;

    #[tokio::test]
    async fn fake_wallet_setup_filters_custom_methods_by_unit() {
        let fake_wallet = config::FakeWallet {
            supported_units: vec![CurrencyUnit::Sat, CurrencyUnit::Usd],
            custom_payment_methods: vec![
                config::FakeWalletCustomPaymentMethod::MethodForUnit {
                    method: "paypal".to_string(),
                    unit: CurrencyUnit::Sat,
                },
                config::FakeWalletCustomPaymentMethod::MethodForUnit {
                    method: "venmo".to_string(),
                    unit: CurrencyUnit::Usd,
                },
                config::FakeWalletCustomPaymentMethod::Method("cashapp".to_string()),
            ],
            min_delay_time: 0,
            max_delay_time: 0,
            ..Default::default()
        };

        let sat_wallet = fake_wallet
            .setup(
                &Settings::default(),
                CurrencyUnit::Sat,
                None,
                Path::new("."),
                None,
            )
            .await
            .expect("sat fake wallet should set up");
        let sat_settings = sat_wallet
            .get_settings()
            .await
            .expect("sat fake wallet settings should load");

        assert!(sat_settings.custom.contains_key("paypal"));
        assert!(sat_settings.custom.contains_key("cashapp"));
        assert!(!sat_settings.custom.contains_key("venmo"));

        let usd_wallet = fake_wallet
            .setup(
                &Settings::default(),
                CurrencyUnit::Usd,
                None,
                Path::new("."),
                None,
            )
            .await
            .expect("usd fake wallet should set up");
        let usd_settings = usd_wallet
            .get_settings()
            .await
            .expect("usd fake wallet settings should load");

        assert!(!usd_settings.custom.contains_key("paypal"));
        assert!(usd_settings.custom.contains_key("cashapp"));
        assert!(usd_settings.custom.contains_key("venmo"));
    }
}

#[cfg(feature = "grpc-processor")]
#[async_trait]
impl PaymentBackendSetup for config::GrpcProcessor {
    async fn setup(
        &self,
        _settings: &Settings,
        _unit: CurrencyUnit,
        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        _work_dir: &Path,
        _kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<cdk_payment_processor::PaymentProcessorClient> {
        let tls_dir = grpc_processor_tls_dir(self)?;

        let payment_processor =
            cdk_payment_processor::PaymentProcessorClient::new(&self.address, self.port, tls_dir)
                .await?;

        Ok(payment_processor)
    }
}

#[cfg(feature = "grpc-processor")]
fn grpc_processor_tls_dir(processor: &config::GrpcProcessor) -> anyhow::Result<Option<PathBuf>> {
    match (&processor.tls_dir, processor.allow_insecure) {
        (Some(tls_dir), _) => Ok(Some(tls_dir.clone())),
        (None, false) => anyhow::bail!(
            "gRPC payment processor TLS is not configured. Set [grpc_processor].tls_dir \
             or [grpc_processor].allow_insecure = true to connect without TLS"
        ),
        (None, true) => {
            tracing::warn!(
                address = %processor.address,
                port = processor.port,
                "SECURITY WARNING: connecting to the gRPC payment processor without TLS because \
                 allow_insecure is true; traffic is unencrypted and unauthenticated and can be \
                 intercepted or modified"
            );

            Ok(None)
        }
    }
}

#[cfg(all(test, feature = "grpc-processor"))]
mod grpc_processor_tests {
    use super::grpc_processor_tls_dir;
    use crate::config::GrpcProcessor;

    #[test]
    fn remote_plaintext_processor_requires_explicit_opt_in() {
        let mut processor = GrpcProcessor {
            address: "192.0.2.1".to_string(),
            ..Default::default()
        };

        let error = grpc_processor_tls_dir(&processor)
            .expect_err("plaintext should require explicit opt-in");
        assert!(error
            .to_string()
            .contains("allow_insecure = true to connect without TLS"));

        processor.allow_insecure = true;
        assert_eq!(
            grpc_processor_tls_dir(&processor).expect("remote plaintext should be allowed"),
            None
        );
    }
}

#[cfg(feature = "ldk-node")]
impl config::LdkNode {
    fn chain_source(&self) -> anyhow::Result<cdk_ldk_node::ChainSource> {
        use anyhow::bail;

        let chain_source_type = self
            .chain_source_type
            .as_ref()
            .map(|source| source.to_lowercase())
            .unwrap_or_else(|| "esplora".to_string());

        match chain_source_type.as_str() {
            "esplora" => {
                let esplora_url = self.esplora_url.clone().ok_or_else(|| {
                    anyhow::anyhow!(
                        "LDK Node esplora_url must be set when chain_source_type is esplora"
                    )
                })?;
                Ok(cdk_ldk_node::ChainSource::Esplora(esplora_url))
            }
            "electrum" => {
                let electrum_url = self.electrum_url.clone().ok_or_else(|| {
                    anyhow::anyhow!(
                        "LDK Node electrum_url must be set when chain_source_type is electrum"
                    )
                })?;
                Ok(cdk_ldk_node::ChainSource::Electrum(electrum_url))
            }
            "bitcoinrpc" => {
                let host = self
                    .bitcoind_rpc_host
                    .clone()
                    .unwrap_or_else(|| "127.0.0.1".to_string());
                let port = self.bitcoind_rpc_port.unwrap_or(18443);
                let user = self
                    .bitcoind_rpc_user
                    .clone()
                    .unwrap_or_else(|| "testuser".to_string());
                let password = self
                    .bitcoind_rpc_password
                    .clone()
                    .unwrap_or_else(|| "testpass".to_string());

                Ok(cdk_ldk_node::ChainSource::BitcoinRpc(
                    cdk_ldk_node::BitcoinRpcConfig {
                        host,
                        port,
                        user,
                        password,
                    },
                ))
            }
            _ => bail!("Unknown LDK Node chain_source_type: {chain_source_type}"),
        }
    }
}

#[cfg(all(test, feature = "ldk-node"))]
mod ldk_node_tests {
    use super::*;

    #[test]
    fn parses_electrum_chain_source() {
        let config = config::LdkNode {
            chain_source_type: Some("ElEcTrUm".to_string()),
            electrum_url: Some("ssl://electrum.example.com:50002".to_string()),
            ..Default::default()
        };

        match config.chain_source().expect("electrum config should parse") {
            cdk_ldk_node::ChainSource::Electrum(url) => {
                assert_eq!(url, "ssl://electrum.example.com:50002");
            }
            _ => panic!("expected an Electrum chain source"),
        }
    }

    #[test]
    fn esplora_chain_source_requires_url() {
        let config = config::LdkNode {
            chain_source_type: Some("esplora".to_string()),
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("esplora config without a URL should fail");

        assert!(error.to_string().contains("esplora_url must be set"));
    }

    #[test]
    fn electrum_chain_source_requires_url() {
        let config = config::LdkNode {
            chain_source_type: Some("electrum".to_string()),
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("electrum config without a URL should fail");

        assert!(error.to_string().contains("electrum_url must be set"));
    }

    #[test]
    fn rejects_unknown_chain_source() {
        let config = config::LdkNode {
            chain_source_type: Some("unknown".to_string()),
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("unknown chain source should fail");

        assert_eq!(
            error.to_string(),
            "Unknown LDK Node chain_source_type: unknown"
        );
    }
}

#[cfg(feature = "ldk-node")]
#[async_trait]
impl PaymentBackendSetup for config::LdkNode {
    async fn setup(
        &self,
        settings: &Settings,
        _unit: CurrencyUnit,
        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        work_dir: &Path,
        kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<cdk_ldk_node::CdkLdkNode> {
        use std::net::SocketAddr;

        use anyhow::bail;
        use bip39::Mnemonic;
        use bitcoin::Network;

        let fee_reserve = FeeReserve {
            min_fee_reserve: self.reserve_fee_min,
            percent_fee_reserve: self.fee_percent,
        };

        // Parse network from config
        let network_str = self.bitcoin_network.as_ref().ok_or_else(|| {
            anyhow::anyhow!("LDK Node bitcoin_network must be set in [ldk_node].bitcoin_network")
        })?;

        let network = match network_str.to_lowercase().as_str() {
            "mainnet" | "bitcoin" => Network::Bitcoin,
            "testnet" => Network::Testnet,
            "signet" => Network::Signet,
            "regtest" => Network::Regtest,
            _ => bail!("Unknown LDK Node bitcoin_network: {}", network_str),
        };

        // Parse chain source from config
        let chain_source = self.chain_source()?;

        // Parse gossip source from config
        let gossip_source = match self.rgs_url.clone() {
            Some(rgs_url) => cdk_ldk_node::GossipSource::RapidGossipSync(rgs_url),
            None => cdk_ldk_node::GossipSource::P2P,
        };

        // Get storage directory path
        let storage_dir_path = if let Some(dir_path) = &self.storage_dir_path {
            dir_path.clone()
        } else {
            let mut work_dir = work_dir.to_path_buf();
            work_dir.push("ldk-node");
            work_dir.to_string_lossy().to_string()
        };

        // Get LDK node listen address
        let host = self
            .ldk_node_host
            .clone()
            .unwrap_or_else(|| "127.0.0.1".to_string());
        let port = self.ldk_node_port.unwrap_or(8090);

        let socket_addr = SocketAddr::new(host.parse()?, port);

        // Parse socket address using ldk_node's SocketAddress
        // We need to get the actual socket address struct from ldk_node
        // For now, let's construct it manually based on the cdk-ldk-node implementation
        let listen_address = vec![socket_addr.into()];

        // Check if ldk_node_mnemonic is provided in the ldk_node config
        let mnemonic_opt = settings
            .clone()
            .ldk_node
            .as_ref()
            .and_then(|ldk_config| ldk_config.ldk_node_mnemonic.clone());

        // Only set seed if mnemonic is explicitly provided
        // This maintains backward compatibility with existing nodes that use LDK's default seed storage
        let seed = if let Some(mnemonic_str) = mnemonic_opt {
            Some(
                mnemonic_str
                    .parse::<Mnemonic>()
                    .map_err(|e| anyhow::anyhow!("invalid ldk_node_mnemonic in config: {e}"))?,
            )
        } else {
            // Check if this is a new node or an existing node
            let storage_dir = PathBuf::from(&storage_dir_path);
            let keys_seed_file = storage_dir.join("keys_seed");

            if !keys_seed_file.exists() {
                bail!("ldk_node_mnemonic should be set in the [ldk_node] configuration section.");
            }

            // Existing node with stored seed, don't set a mnemonic
            None
        };

        let ldk_node_settings = settings
            .ldk_node
            .as_ref()
            .ok_or_else(|| anyhow::anyhow!("ldk_node configuration is required"))?;
        let announce_addrs: Vec<_> = ldk_node_settings
            .ldk_node_announce_addresses
            .as_ref()
            .map(|addrs| addrs.iter().filter_map(|addr| addr.parse().ok()).collect())
            .unwrap_or_default();

        let kv_store = kv_store.ok_or_else(|| anyhow::anyhow!("LdkNode needs a KV store"))?;

        let mut ldk_node_builder = cdk_ldk_node::CdkLdkNodeBuilder::new(
            network,
            chain_source,
            gossip_source,
            storage_dir_path,
            fee_reserve,
            listen_address,
            kv_store,
        );

        // Only set seed if provided
        if let Some(mnemonic) = seed {
            ldk_node_builder = ldk_node_builder.with_seed(mnemonic);
        }

        if !announce_addrs.is_empty() {
            ldk_node_builder = ldk_node_builder.with_announcement_address(announce_addrs)
        }
        // Configure webserver address if specified
        let webserver_addr = if let Some(host) = &self.webserver_host {
            let port = self.webserver_port.unwrap_or(8091);
            let socket_addr: SocketAddr = format!("{host}:{port}").parse()?;
            Some(socket_addr)
        } else if self.webserver_port.is_some() {
            // If only port is specified, use default host
            let port = self.webserver_port.unwrap_or(8091);
            let socket_addr: SocketAddr = format!("127.0.0.1:{port}").parse()?;
            Some(socket_addr)
        } else {
            // Use default webserver address if nothing is configured
            Some(cdk_ldk_node::CdkLdkNode::default_web_addr())
        };

        if let Some(log_dir_path) = ldk_node_settings.log_dir_path.as_ref() {
            ldk_node_builder = ldk_node_builder.with_log_dir_path(log_dir_path.clone());
        }
        let mut ldk_node = ldk_node_builder.build()?;
        ldk_node.set_web_addr(webserver_addr);

        Ok(ldk_node)
    }
}

#[cfg(feature = "bdk")]
impl crate::config::Bdk {
    fn wallet_identity(&self) -> Result<(bip39::Mnemonic, bitcoin::Network), cdk_bdk::Error> {
        let network_str = self.network.as_ref().ok_or_else(|| {
            cdk_bdk::Error::InvalidConfig("BDK network must be set in [bdk].network".to_string())
        })?;
        let network = match network_str.to_lowercase().as_str() {
            "mainnet" | "bitcoin" => bitcoin::Network::Bitcoin,
            "testnet" => bitcoin::Network::Testnet,
            "signet" => bitcoin::Network::Signet,
            "regtest" => bitcoin::Network::Regtest,
            _ => {
                return Err(cdk_bdk::Error::InvalidConfig(format!(
                    "Unknown BDK network: {network_str}"
                )));
            }
        };
        let mnemonic = self
            .mnemonic
            .as_ref()
            .ok_or_else(|| cdk_bdk::Error::InvalidConfig("BDK mnemonic must be set".to_string()))?;
        let mnemonic = bip39::Mnemonic::parse(mnemonic)
            .map_err(|error| cdk_bdk::Error::InvalidConfig(error.to_string()))?;

        Ok((mnemonic, network))
    }

    pub(crate) fn validate_wallet_identity(&self) -> Result<(), cdk_bdk::Error> {
        self.wallet_identity().map(|_| ())
    }

    pub(crate) fn validate_existing_wallet(&self, work_dir: &Path) -> Result<(), cdk_bdk::Error> {
        let (mnemonic, network) = self.wallet_identity()?;
        cdk_bdk::validate_existing_wallet(mnemonic, network, work_dir)?;
        Ok(())
    }

    fn chain_source(&self) -> anyhow::Result<cdk_bdk::ChainSource> {
        use anyhow::bail;

        let chain_source_type = self
            .chain_source_type
            .as_deref()
            .unwrap_or("bitcoinrpc")
            .to_lowercase();

        match chain_source_type.as_str() {
            "esplora" => {
                let esplora_url = self.esplora_url.clone().ok_or_else(|| {
                    anyhow::anyhow!("BDK esplora_url must be set when chain_source_type is esplora")
                })?;
                Ok(cdk_bdk::ChainSource::Esplora(cdk_bdk::EsploraConfig {
                    url: esplora_url,
                    parallel_requests: self.esplora_parallel_requests.max(1),
                }))
            }
            "electrum" => {
                let electrum_url = self.electrum_url.clone().ok_or_else(|| {
                    anyhow::anyhow!(
                        "BDK electrum_url must be set when chain_source_type is electrum"
                    )
                })?;
                if self.electrum_batch_size == 0 {
                    bail!("BDK electrum_batch_size must be greater than zero");
                }
                Ok(cdk_bdk::ChainSource::Electrum(cdk_bdk::ElectrumConfig {
                    url: electrum_url,
                    batch_size: self.electrum_batch_size,
                }))
            }
            "bitcoinrpc" => {
                let host = self
                    .bitcoind_rpc_host
                    .clone()
                    .unwrap_or_else(|| "127.0.0.1".to_string());
                let port = self.bitcoind_rpc_port.unwrap_or(18443);
                let user = self
                    .bitcoind_rpc_user
                    .clone()
                    .unwrap_or_else(|| "user".to_string());
                let password = self
                    .bitcoind_rpc_password
                    .clone()
                    .unwrap_or_else(|| "pass".to_string());

                Ok(cdk_bdk::ChainSource::BitcoinRpc(
                    cdk_bdk::BitcoinRpcConfig {
                        host,
                        port,
                        user,
                        password,
                        wallet_rescan_from_height: self.wallet_rescan_from_height,
                    },
                ))
            }
            _ => bail!("Unknown BDK chain_source_type: {chain_source_type}"),
        }
    }
}

#[cfg(all(test, feature = "bdk"))]
mod bdk_tests {
    use super::*;

    #[test]
    fn forwards_bitcoin_rpc_wallet_rescan_height() {
        let config = config::Bdk {
            chain_source_type: Some("bitcoinrpc".to_string()),
            wallet_rescan_from_height: Some(850000),
            ..Default::default()
        };

        match config
            .chain_source()
            .expect("Bitcoin RPC config should parse")
        {
            cdk_bdk::ChainSource::BitcoinRpc(config) => {
                assert_eq!(config.wallet_rescan_from_height, Some(850000));
            }
            _ => panic!("expected a Bitcoin RPC chain source"),
        }
    }

    #[test]
    fn parses_electrum_chain_source() {
        let config = config::Bdk {
            chain_source_type: Some("ElEcTrUm".to_string()),
            electrum_url: Some("ssl://electrum.example.com:50002".to_string()),
            electrum_batch_size: 7,
            ..Default::default()
        };

        match config.chain_source().expect("electrum config should parse") {
            cdk_bdk::ChainSource::Electrum(config) => {
                assert_eq!(config.url, "ssl://electrum.example.com:50002");
                assert_eq!(config.batch_size, 7);
            }
            _ => panic!("expected an Electrum chain source"),
        }
    }

    #[test]
    fn electrum_chain_source_requires_url() {
        let config = config::Bdk {
            chain_source_type: Some("electrum".to_string()),
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("electrum config without a URL should fail");

        assert!(error.to_string().contains("electrum_url must be set"));
    }

    #[test]
    fn electrum_chain_source_rejects_zero_batch_size() {
        let config = config::Bdk {
            chain_source_type: Some("electrum".to_string()),
            electrum_url: Some("tcp://127.0.0.1:50001".to_string()),
            electrum_batch_size: 0,
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("zero Electrum batch size should fail");

        assert!(error
            .to_string()
            .contains("electrum_batch_size must be greater than zero"));
    }

    #[test]
    fn esplora_chain_source_requires_url() {
        let config = config::Bdk {
            chain_source_type: Some("esplora".to_string()),
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("esplora config without a URL should fail");

        assert!(error.to_string().contains("esplora_url must be set"));
    }

    #[test]
    fn rejects_unknown_chain_source() {
        let config = config::Bdk {
            chain_source_type: Some("unknown".to_string()),
            ..Default::default()
        };

        let error = config
            .chain_source()
            .expect_err("unknown chain source should fail");

        assert_eq!(error.to_string(), "Unknown BDK chain_source_type: unknown");
    }
}

#[cfg(feature = "bdk")]
#[async_trait]
impl OnchainBackendSetup for crate::config::Bdk {
    async fn setup(
        &self,
        settings: &Settings,
        _unit: CurrencyUnit,
        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
        work_dir: &Path,
        kv_store: Option<Arc<dyn KVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
    ) -> anyhow::Result<cdk_bdk::CdkBdk> {
        self.validate().map_err(anyhow::Error::msg)?;

        let fee_reserve = FeeReserve {
            min_fee_reserve: self.reserve_fee_min,
            percent_fee_reserve: self.fee_percent,
        };

        let (mnemonic, network) = self.wallet_identity()?;

        let chain_source = self.chain_source()?;

        let min_receive_amount_sat = settings
            .onchain
            .as_ref()
            .map(|onchain| onchain.min_mint.to_u64().max(self.min_receive_amount_sat))
            .unwrap_or(self.min_receive_amount_sat);

        let bdk = cdk_bdk::CdkBdk::new(
            mnemonic,
            network,
            chain_source,
            work_dir.to_string_lossy().to_string(),
            fee_reserve,
            kv_store.ok_or_else(|| anyhow::anyhow!("BDK backend requires a KV store"))?,
            Some(self.batch_config.clone().into()),
            self.num_confs,
            min_receive_amount_sat,
            self.min_send_amount_sat,
            self.sync_interval_secs,
            None,
            None,
        )?;

        Ok(bdk)
    }
}

#[cfg(feature = "bdk")]
impl From<crate::config::BatchConfig> for cdk_bdk::BatchConfig {
    fn from(config: crate::config::BatchConfig) -> Self {
        let target_block_time = Duration::from_secs(config.target_block_time_secs);
        let standard_deadline = config
            .standard_deadline_secs
            .map(Duration::from_secs)
            .unwrap_or_else(|| {
                cdk_bdk::BatchConfig::deadline_for_target_blocks(
                    cdk_bdk::PaymentTier::Standard,
                    target_block_time,
                )
            });
        let economy_deadline = config
            .economy_deadline_secs
            .map(Duration::from_secs)
            .unwrap_or_else(|| {
                cdk_bdk::BatchConfig::deadline_for_target_blocks(
                    cdk_bdk::PaymentTier::Economy,
                    target_block_time,
                )
            });
        let fee_estimation = cdk_bdk::FeeEstimationConfig {
            fallback_sat_per_vb: config.fee_fallback_sat_per_vb,
            cache_ttl_secs: config.fee_cache_ttl_secs,
            quote_max_input_count: config.quote_max_input_count,
            quote_fixed_safety_sat: config.quote_fixed_safety_sat,
            quote_safety_multiplier: config.quote_safety_multiplier,
        };

        Self {
            poll_interval: Duration::from_secs(config.poll_interval_secs),
            max_batch_size: config.max_batch_size,
            target_block_time,
            standard_deadline,
            economy_deadline,
            max_intent_age: Some(
                economy_deadline.saturating_add(Duration::from_secs(config.poll_interval_secs)),
            ),
            fee_options: config
                .fee_options
                .iter()
                .map(|tier| {
                    cdk_bdk::PaymentTier::from_config_name(tier)
                        .expect("BDK fee_options should be validated before setup")
                })
                .collect(),
            fee_estimation,
        }
    }
}