archy/core/archipelago/src/api/rpc/lnd.rs

use super::RpcHandler;
use anyhow::{Context, Result};
use base64::Engine;
use serde::{Deserialize, Serialize};
use tracing::info;

#[derive(Debug, Serialize)]
struct LndInfo {
    alias: String,
    num_active_channels: u32,
    num_peers: u32,
    synced_to_chain: bool,
    block_height: u64,
    balance_sats: i64,
    channel_balance_sats: i64,
    pending_open_balance: i64,
}

#[derive(Debug, Deserialize)]
struct LndGetInfoResponse {
    alias: Option<String>,
    num_active_channels: Option<u32>,
    num_peers: Option<u32>,
    synced_to_chain: Option<bool>,
    block_height: Option<u64>,
}

#[derive(Debug, Deserialize)]
struct LndChannelBalanceResponse {
    local_balance: Option<LndAmount>,
    pending_open_local_balance: Option<LndAmount>,
}

#[derive(Debug, Deserialize)]
struct LndBalanceResponse {
    total_balance: Option<String>,
}

#[derive(Debug, Deserialize)]
struct LndAmount {
    sat: Option<String>,
}

impl RpcHandler {
    pub(super) async fn handle_lnd_getinfo(&self) -> Result<serde_json::Value> {
        let macaroon_path =
            "/var/lib/archipelago/lnd/data/chain/bitcoin/mainnet/admin.macaroon";

        let macaroon_bytes = tokio::fs::read(macaroon_path)
            .await
            .context("Failed to read LND admin macaroon — is LND installed?")?;
        let macaroon_hex = hex::encode(&macaroon_bytes);

        let client = reqwest::Client::builder()
            .timeout(std::time::Duration::from_secs(10))
            .danger_accept_invalid_certs(true)
            .build()
            .context("Failed to create HTTP client")?;

        let get_info: LndGetInfoResponse = client
            .get("https://127.0.0.1:8080/v1/getinfo")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
            .context("LND REST connection failed")?
            .json()
            .await
            .context("Failed to parse LND getinfo response")?;

        let channel_balance: LndChannelBalanceResponse = match client
            .get("https://127.0.0.1:8080/v1/balance/channels")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
        {
            Ok(resp) => resp.json().await.unwrap_or(LndChannelBalanceResponse {
                local_balance: None,
                pending_open_local_balance: None,
            }),
            Err(_) => LndChannelBalanceResponse {
                local_balance: None,
                pending_open_local_balance: None,
            },
        };

        let wallet_balance: LndBalanceResponse = match client
            .get("https://127.0.0.1:8080/v1/balance/blockchain")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
        {
            Ok(resp) => resp.json().await.unwrap_or(LndBalanceResponse {
                total_balance: None,
            }),
            Err(_) => LndBalanceResponse {
                total_balance: None,
            },
        };

        let info = LndInfo {
            alias: get_info.alias.unwrap_or_default(),
            num_active_channels: get_info.num_active_channels.unwrap_or(0),
            num_peers: get_info.num_peers.unwrap_or(0),
            synced_to_chain: get_info.synced_to_chain.unwrap_or(false),
            block_height: get_info.block_height.unwrap_or(0),
            balance_sats: wallet_balance
                .total_balance
                .and_then(|s| s.parse().ok())
                .unwrap_or(0),
            channel_balance_sats: channel_balance
                .local_balance
                .and_then(|a| a.sat.and_then(|s| s.parse().ok()))
                .unwrap_or(0),
            pending_open_balance: channel_balance
                .pending_open_local_balance
                .and_then(|a| a.sat.and_then(|s| s.parse().ok()))
                .unwrap_or(0),
        };

        Ok(serde_json::to_value(info)?)
    }

    /// Helper: create an authenticated LND REST client
    pub(crate) async fn lnd_client(&self) -> Result<(reqwest::Client, String)> {
        let macaroon_path =
            "/var/lib/archipelago/lnd/data/chain/bitcoin/mainnet/admin.macaroon";
        let macaroon_bytes = tokio::fs::read(macaroon_path)
            .await
            .context("Failed to read LND admin macaroon — is LND installed?")?;
        let macaroon_hex = hex::encode(&macaroon_bytes);
        let client = reqwest::Client::builder()
            .timeout(std::time::Duration::from_secs(15))
            .danger_accept_invalid_certs(true)
            .build()
            .context("Failed to create HTTP client")?;
        Ok((client, macaroon_hex))
    }

    pub(super) async fn handle_lnd_listchannels(&self) -> Result<serde_json::Value> {
        let (client, macaroon_hex) = self.lnd_client().await?;

        let channels_resp: LndListChannelsResponse = client
            .get("https://127.0.0.1:8080/v1/channels")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
            .context("LND REST connection failed")?
            .json()
            .await
            .context("Failed to parse LND channels response")?;

        let pending_resp: LndPendingChannelsResponse = match client
            .get("https://127.0.0.1:8080/v1/channels/pending")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
        {
            Ok(resp) => resp.json().await.unwrap_or_default(),
            Err(_) => LndPendingChannelsResponse::default(),
        };

        let channels: Vec<ChannelInfo> = channels_resp
            .channels
            .unwrap_or_default()
            .into_iter()
            .map(|ch| {
                let capacity: i64 = ch.capacity.as_deref().and_then(|s| s.parse().ok()).unwrap_or(0);
                let local: i64 = ch.local_balance.as_deref().and_then(|s| s.parse().ok()).unwrap_or(0);
                let remote: i64 = ch.remote_balance.as_deref().and_then(|s| s.parse().ok()).unwrap_or(0);
                ChannelInfo {
                    chan_id: ch.chan_id.unwrap_or_default(),
                    remote_pubkey: ch.remote_pubkey.unwrap_or_default(),
                    capacity,
                    local_balance: local,
                    remote_balance: remote,
                    active: ch.active.unwrap_or(false),
                    status: if ch.active.unwrap_or(false) { "active".into() } else { "inactive".into() },
                    channel_point: ch.channel_point.unwrap_or_default(),
                }
            })
            .collect();

        let mut pending_channels: Vec<ChannelInfo> = Vec::new();
        for pch in pending_resp.pending_open_channels.unwrap_or_default() {
            if let Some(ch) = pch.channel {
                let capacity: i64 = ch.capacity.as_deref().and_then(|s| s.parse().ok()).unwrap_or(0);
                let local: i64 = ch.local_balance.as_deref().and_then(|s| s.parse().ok()).unwrap_or(0);
                let remote: i64 = ch.remote_balance.as_deref().and_then(|s| s.parse().ok()).unwrap_or(0);
                pending_channels.push(ChannelInfo {
                    chan_id: String::new(),
                    remote_pubkey: ch.remote_node_pub.unwrap_or_default(),
                    capacity,
                    local_balance: local,
                    remote_balance: remote,
                    active: false,
                    status: "pending_open".into(),
                    channel_point: ch.channel_point.unwrap_or_default(),
                });
            }
        }

        let total_local: i64 = channels.iter().map(|c| c.local_balance).sum();
        let total_remote: i64 = channels.iter().map(|c| c.remote_balance).sum();

        let mut all_channels = channels;
        all_channels.extend(pending_channels);

        let result = ChannelListResult {
            channels: all_channels,
            total_inbound: total_remote,
            total_outbound: total_local,
        };

        Ok(serde_json::to_value(result)?)
    }

    pub(super) async fn handle_lnd_openchannel(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.unwrap_or_default();
        let pubkey = params.get("pubkey")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("Missing 'pubkey' parameter"))?;
        let amount = params.get("amount")
            .and_then(|v| v.as_i64())
            .ok_or_else(|| anyhow::anyhow!("Missing 'amount' parameter (sats)"))?;

        // Validate pubkey: must be 66-char hex (compressed secp256k1)
        if pubkey.len() != 66 || !pubkey.chars().all(|c| c.is_ascii_hexdigit()) {
            return Err(anyhow::anyhow!("Invalid pubkey: must be 66-character hex string"));
        }

        if amount < 20000 {
            return Err(anyhow::anyhow!("Channel amount must be at least 20,000 sats"));
        }
        if amount > 16_777_215 {
            return Err(anyhow::anyhow!("Channel amount exceeds maximum (16,777,215 sats)"));
        }

        info!(peer = pubkey, amount = amount, "Opening Lightning channel");

        let (client, macaroon_hex) = self.lnd_client().await?;

        // First connect to the peer if an address is provided
        if let Some(addr) = params.get("address").and_then(|v| v.as_str()) {
            // Validate peer address format (host:port)
            if addr.len() > 256 || addr.contains('\0') || addr.contains(' ') {
                return Err(anyhow::anyhow!("Invalid peer address format"));
            }
            let connect_body = serde_json::json!({
                "addr": { "pubkey": pubkey, "host": addr },
                "perm": true
            });
            let _ = client
                .post("https://127.0.0.1:8080/v1/peers")
                .header("Grpc-Metadata-macaroon", &macaroon_hex)
                .json(&connect_body)
                .send()
                .await;
        }

        let open_body = serde_json::json!({
            "node_pubkey_string": pubkey,
            "local_funding_amount": amount.to_string(),
        });

        let resp = client
            .post("https://127.0.0.1:8080/v1/channels")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&open_body)
            .send()
            .await
            .context("Failed to open channel")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await.context("Failed to parse open channel response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to open channel: {}", msg));
        }

        Ok(body)
    }

    pub(super) async fn handle_lnd_closechannel(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.unwrap_or_default();
        let channel_point = params.get("channel_point")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("Missing 'channel_point' parameter (txid:output_index)"))?;

        let parts: Vec<&str> = channel_point.split(':').collect();
        if parts.len() != 2 {
            return Err(anyhow::anyhow!("Invalid channel_point format. Expected 'txid:output_index'"));
        }
        // Validate txid is 64-char hex and output_index is numeric
        if parts[0].len() != 64 || !parts[0].chars().all(|c| c.is_ascii_hexdigit()) {
            return Err(anyhow::anyhow!("Invalid txid in channel_point: must be 64-character hex"));
        }
        if parts[1].parse::<u32>().is_err() {
            return Err(anyhow::anyhow!("Invalid output_index in channel_point: must be a number"));
        }

        let force = params.get("force").and_then(|v| v.as_bool()).unwrap_or(false);
        info!(channel_point = channel_point, force = force, "Closing Lightning channel");

        let (client, macaroon_hex) = self.lnd_client().await?;

        let url = format!(
            "https://127.0.0.1:8080/v1/channels/{}/{}?force={}",
            parts[0], parts[1], force
        );

        let resp = client
            .delete(&url)
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
            .context("Failed to close channel")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await.context("Failed to parse close channel response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to close channel: {}", msg));
        }

        Ok(serde_json::json!({ "success": true }))
    }

    /// Generate a new on-chain Bitcoin address.
    pub(super) async fn handle_lnd_newaddress(&self) -> Result<serde_json::Value> {
        let (client, macaroon_hex) = self.lnd_client().await?;

        let resp = client
            .get("https://127.0.0.1:8080/v1/newaddress")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
            .context("LND REST connection failed")?;

        let body: serde_json::Value = resp.json().await
            .context("Failed to parse newaddress response")?;

        let address = body.get("address")
            .and_then(|v| v.as_str())
            .unwrap_or("")
            .to_string();

        Ok(serde_json::json!({ "address": address }))
    }

    /// Send on-chain Bitcoin to an address.
    pub(super) async fn handle_lnd_sendcoins(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.unwrap_or_default();
        let addr = params.get("addr")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("Missing 'addr' parameter"))?;
        let amount = params.get("amount")
            .and_then(|v| v.as_i64())
            .ok_or_else(|| anyhow::anyhow!("Missing 'amount' parameter (sats)"))?;

        if amount < 546 {
            return Err(anyhow::anyhow!("Amount must be at least 546 sats (dust limit)"));
        }
        if amount > 21_000_000 * 100_000_000 {
            return Err(anyhow::anyhow!("Amount exceeds maximum Bitcoin supply"));
        }

        // Validate Bitcoin address format (basic: length and allowed chars)
        if addr.len() < 14 || addr.len() > 90 || !addr.chars().all(|c| c.is_ascii_alphanumeric()) {
            return Err(anyhow::anyhow!("Invalid Bitcoin address format"));
        }

        info!(addr = addr, amount = amount, "Sending on-chain Bitcoin");

        let (client, macaroon_hex) = self.lnd_client().await?;

        let send_body = serde_json::json!({
            "addr": addr,
            "amount": amount.to_string(),
        });

        let resp = client
            .post("https://127.0.0.1:8080/v1/transactions")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&send_body)
            .send()
            .await
            .context("Failed to send on-chain transaction")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse send response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to send: {}", msg));
        }

        let txid = body.get("txid").and_then(|v| v.as_str()).unwrap_or("").to_string();
        Ok(serde_json::json!({ "txid": txid }))
    }

    /// Create a Lightning invoice.
    pub(super) async fn handle_lnd_createinvoice(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.unwrap_or_default();
        let amount_sats = params.get("amount_sats")
            .and_then(|v| v.as_i64())
            .ok_or_else(|| anyhow::anyhow!("Missing 'amount_sats' parameter"))?;
        let memo = params.get("memo")
            .and_then(|v| v.as_str())
            .unwrap_or("");

        if amount_sats < 0 {
            return Err(anyhow::anyhow!("Amount must be non-negative"));
        }
        if amount_sats > 21_000_000 * 100_000_000 {
            return Err(anyhow::anyhow!("Amount exceeds maximum Bitcoin supply"));
        }

        // Limit memo length to prevent abuse
        if memo.len() > 639 {
            return Err(anyhow::anyhow!("Memo too long (max 639 bytes)"));
        }

        info!(amount_sats = amount_sats, "Creating Lightning invoice");

        let (client, macaroon_hex) = self.lnd_client().await?;

        let invoice_body = serde_json::json!({
            "value": amount_sats.to_string(),
            "memo": memo,
        });

        let resp = client
            .post("https://127.0.0.1:8080/v1/invoices")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&invoice_body)
            .send()
            .await
            .context("Failed to create invoice")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse invoice response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to create invoice: {}", msg));
        }

        let payment_request = body.get("payment_request")
            .and_then(|v| v.as_str())
            .unwrap_or("")
            .to_string();

        Ok(serde_json::json!({
            "payment_request": payment_request,
            "amount_sats": amount_sats,
        }))
    }

    /// Pay a Lightning invoice.
    pub(super) async fn handle_lnd_payinvoice(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.unwrap_or_default();
        let payment_request = params.get("payment_request")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("Missing 'payment_request' parameter"))?;

        // Basic validation: Lightning invoices start with lnbc/lntb/lnbcrt
        if payment_request.len() < 10 || payment_request.len() > 2048 {
            return Err(anyhow::anyhow!("Invalid payment request length"));
        }
        let lower = payment_request.to_lowercase();
        if !lower.starts_with("lnbc") && !lower.starts_with("lntb") && !lower.starts_with("lnbcrt") {
            return Err(anyhow::anyhow!("Invalid payment request: must be a Lightning invoice (lnbc...)"));
        }

        info!("Paying Lightning invoice");

        let (client, macaroon_hex) = self.lnd_client().await?;

        let pay_body = serde_json::json!({
            "payment_request": payment_request,
        });

        let resp = client
            .post("https://127.0.0.1:8080/v1/channels/transactions")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&pay_body)
            .send()
            .await
            .context("Failed to pay invoice")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse payment response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Payment failed: {}", msg));
        }

        let payment_error = body.get("payment_error").and_then(|v| v.as_str()).unwrap_or("");
        if !payment_error.is_empty() {
            return Err(anyhow::anyhow!("Payment failed: {}", payment_error));
        }

        let amount_sat = body.get("payment_route")
            .and_then(|r| r.get("total_amt"))
            .and_then(|v| v.as_str())
            .and_then(|s| s.parse::<i64>().ok())
            .unwrap_or(0);

        let payment_hash = body.get("payment_hash")
            .and_then(|v| v.as_str())
            .unwrap_or("")
            .to_string();

        Ok(serde_json::json!({
            "payment_hash": payment_hash,
            "amount_sats": amount_sat,
        }))
    }
    /// Create an unsigned PSBT for hardware wallet signing.
    /// Uses LND's WalletKit.FundPsbt to select UTXOs and create a PSBT template.
    pub(super) async fn handle_lnd_create_psbt(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.ok_or_else(|| anyhow::anyhow!("Missing params"))?;

        let outputs = params.get("outputs")
            .and_then(|v| v.as_array())
            .ok_or_else(|| anyhow::anyhow!("Missing 'outputs' array (each: address + amount_sats)"))?;

        if outputs.is_empty() {
            return Err(anyhow::anyhow!("outputs must not be empty"));
        }

        // Build the outputs map for LND: { "address": "amount_sats_as_string" }
        let mut lnd_outputs: serde_json::Map<String, serde_json::Value> = serde_json::Map::new();
        let mut total_amount: i64 = 0;
        for output in outputs {
            let addr = output.get("address")
                .and_then(|v| v.as_str())
                .ok_or_else(|| anyhow::anyhow!("Each output must have an 'address'"))?;
            // Validate Bitcoin address format
            if addr.len() < 14 || addr.len() > 90 || !addr.chars().all(|c| c.is_ascii_alphanumeric()) {
                return Err(anyhow::anyhow!("Invalid Bitcoin address format in output"));
            }
            let amount = output.get("amount_sats")
                .and_then(|v| v.as_i64())
                .ok_or_else(|| anyhow::anyhow!("Each output must have 'amount_sats'"))?;
            if amount < 546 {
                return Err(anyhow::anyhow!("Amount must be at least 546 sats (dust limit)"));
            }
            lnd_outputs.insert(addr.to_string(), serde_json::json!(amount));
            total_amount += amount;
        }

        let sat_per_vbyte = params.get("fee_rate_sat_per_vbyte")
            .and_then(|v| v.as_u64())
            .unwrap_or(10);

        info!(total_amount = total_amount, fee_rate = sat_per_vbyte, "Creating PSBT for hardware wallet signing");

        let (client, macaroon_hex) = self.lnd_client().await?;

        let fund_body = serde_json::json!({
            "raw": {
                "outputs": lnd_outputs,
            },
            "sat_per_vbyte": sat_per_vbyte,
            "spend_unconfirmed": false,
        });

        let resp = client
            .post("https://127.0.0.1:8080/v2/wallet/psbt/fund")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&fund_body)
            .send()
            .await
            .context("Failed to create PSBT via LND")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse PSBT response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to create PSBT: {}", msg));
        }

        let funded_psbt = body.get("funded_psbt")
            .and_then(|v| v.as_str())
            .unwrap_or("")
            .to_string();

        let change_output_index = body.get("change_output_index")
            .and_then(|v| v.as_i64())
            .unwrap_or(-1);

        Ok(serde_json::json!({
            "psbt_base64": funded_psbt,
            "change_output_index": change_output_index,
            "total_amount_sats": total_amount,
            "fee_rate_sat_per_vbyte": sat_per_vbyte,
        }))
    }

    /// Finalize a signed PSBT and broadcast the transaction.
    /// Takes a PSBT that has been signed by a hardware wallet.
    pub(super) async fn handle_lnd_finalize_psbt(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.ok_or_else(|| anyhow::anyhow!("Missing params"))?;
        let signed_psbt = params.get("signed_psbt_base64")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("Missing 'signed_psbt_base64'"))?;

        info!("Finalizing signed PSBT from hardware wallet");

        let (client, macaroon_hex) = self.lnd_client().await?;

        let finalize_body = serde_json::json!({
            "funded_psbt": signed_psbt,
        });

        let resp = client
            .post("https://127.0.0.1:8080/v2/wallet/psbt/finalize")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&finalize_body)
            .send()
            .await
            .context("Failed to finalize PSBT via LND")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse finalize response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to finalize PSBT: {}", msg));
        }

        let raw_final_tx = body.get("raw_final_tx")
            .and_then(|v| v.as_str())
            .unwrap_or("")
            .to_string();

        // Broadcast the finalized transaction
        let publish_body = serde_json::json!({
            "tx_hex": raw_final_tx,
        });

        let pub_resp = client
            .post("https://127.0.0.1:8080/v2/wallet/tx")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&publish_body)
            .send()
            .await
            .context("Failed to broadcast transaction")?;

        let pub_status = pub_resp.status();
        let pub_body: serde_json::Value = pub_resp.json().await
            .context("Failed to parse broadcast response")?;

        if !pub_status.is_success() {
            let msg = pub_body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Transaction broadcast failed: {}", msg));
        }

        Ok(serde_json::json!({
            "raw_final_tx": raw_final_tx,
            "broadcast": true,
        }))
    }

    /// Create a signed raw transaction WITHOUT broadcasting.
    /// Used for mesh relay: create the TX locally, then relay the hex to an
    /// internet-connected peer who broadcasts it.
    pub(super) async fn handle_lnd_create_raw_tx(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        let params = params.ok_or_else(|| anyhow::anyhow!("Missing params"))?;

        let addr = params.get("addr")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("Missing 'addr'"))?;
        let amount_sats = params.get("amount_sats")
            .and_then(|v| v.as_u64())
            .ok_or_else(|| anyhow::anyhow!("Missing 'amount_sats'"))?;

        if amount_sats < 546 {
            anyhow::bail!("Amount must be at least 546 sats (dust limit)");
        }
        if amount_sats > 2_100_000_000_000_000 {
            anyhow::bail!("Amount exceeds 21M BTC");
        }

        let (client, macaroon_hex) = self.lnd_client().await?;

        // Step 1: Fund a PSBT with the desired output
        let fee_rate = params.get("fee_rate").and_then(|v| v.as_u64()).unwrap_or(5);
        let fund_body = serde_json::json!({
            "raw": {
                "outputs": { addr: amount_sats }
            },
            "sat_per_vbyte": fee_rate,
            "spend_unconfirmed": false,
        });

        let resp = client
            .post("https://127.0.0.1:8080/v2/wallet/psbt/fund")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&fund_body)
            .send()
            .await
            .context("Failed to fund PSBT via LND")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse fund response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to create TX: {}", msg));
        }

        let funded_psbt = body.get("funded_psbt")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("No funded_psbt in response"))?;

        // Step 2: Finalize (LND auto-signs with hot wallet keys)
        let finalize_body = serde_json::json!({
            "funded_psbt": funded_psbt,
        });

        let resp = client
            .post("https://127.0.0.1:8080/v2/wallet/psbt/finalize")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .json(&finalize_body)
            .send()
            .await
            .context("Failed to finalize PSBT")?;

        let status = resp.status();
        let body: serde_json::Value = resp.json().await
            .context("Failed to parse finalize response")?;

        if !status.is_success() {
            let msg = body.get("message").and_then(|v| v.as_str()).unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to sign TX: {}", msg));
        }

        // raw_final_tx from LND is base64-encoded — decode to hex for Bitcoin RPC
        let raw_final_tx_b64 = body.get("raw_final_tx")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow::anyhow!("No raw_final_tx in response"))?;

        use base64::Engine;
        let tx_bytes = base64::engine::general_purpose::STANDARD
            .decode(raw_final_tx_b64)
            .context("Failed to decode raw_final_tx base64")?;
        let raw_tx_hex = hex::encode(&tx_bytes);

        info!(addr, amount_sats, tx_len = raw_tx_hex.len(), "Created raw TX for mesh relay (NOT broadcast)");

        Ok(serde_json::json!({
            "raw_tx_hex": raw_tx_hex,
            "amount_sats": amount_sats,
            "addr": addr,
            "broadcast": false,
        }))
    }

    /// List on-chain transactions from LND.
    /// Returns all transactions, with incoming (amount > 0) flagged.
    pub(super) async fn handle_lnd_gettransactions(&self) -> Result<serde_json::Value> {
        let (client, macaroon_hex) = self.lnd_client().await?;

        let resp = client
            .get("https://127.0.0.1:8080/v1/transactions")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
            .context("LND REST connection failed")?;

        let status = resp.status();
        let body: serde_json::Value = resp
            .json()
            .await
            .context("Failed to parse transactions response")?;

        if !status.is_success() {
            let msg = body
                .get("message")
                .and_then(|v| v.as_str())
                .unwrap_or("Unknown error");
            return Err(anyhow::anyhow!("Failed to list transactions: {}", msg));
        }

        let empty_vec = vec![];
        let raw_txs = body
            .get("transactions")
            .and_then(|v| v.as_array())
            .unwrap_or(&empty_vec);

        let mut transactions: Vec<serde_json::Value> = Vec::new();
        for tx in raw_txs {
            let amount: i64 = tx
                .get("amount")
                .and_then(|v| v.as_str())
                .and_then(|s| s.parse().ok())
                .or_else(|| tx.get("amount").and_then(|v| v.as_i64()))
                .unwrap_or(0);

            let num_confirmations: i64 = tx
                .get("num_confirmations")
                .and_then(|v| v.as_i64())
                .unwrap_or(0);

            let tx_hash = tx
                .get("tx_hash")
                .and_then(|v| v.as_str())
                .unwrap_or("")
                .to_string();

            let time_stamp: i64 = tx
                .get("time_stamp")
                .and_then(|v| v.as_str())
                .and_then(|s| s.parse().ok())
                .or_else(|| tx.get("time_stamp").and_then(|v| v.as_i64()))
                .unwrap_or(0);

            let total_fees: i64 = tx
                .get("total_fees")
                .and_then(|v| v.as_str())
                .and_then(|s| s.parse().ok())
                .or_else(|| tx.get("total_fees").and_then(|v| v.as_i64()))
                .unwrap_or(0);

            let dest_addresses: Vec<String> = tx
                .get("dest_addresses")
                .and_then(|v| v.as_array())
                .map(|arr| {
                    arr.iter()
                        .filter_map(|a| a.as_str().map(|s| s.to_string()))
                        .collect()
                })
                .unwrap_or_default();

            let label = tx
                .get("label")
                .and_then(|v| v.as_str())
                .unwrap_or("")
                .to_string();

            let block_height: i64 = tx
                .get("block_height")
                .and_then(|v| v.as_i64())
                .unwrap_or(0);

            let direction = if amount > 0 { "incoming" } else { "outgoing" };

            transactions.push(serde_json::json!({
                "tx_hash": tx_hash,
                "amount_sats": amount.abs(),
                "direction": direction,
                "num_confirmations": num_confirmations,
                "time_stamp": time_stamp,
                "total_fees": total_fees,
                "dest_addresses": dest_addresses,
                "label": label,
                "block_height": block_height,
            }));
        }

        // Sort by timestamp descending (most recent first)
        transactions.sort_by(|a, b| {
            let ta = a.get("time_stamp").and_then(|v| v.as_i64()).unwrap_or(0);
            let tb = b.get("time_stamp").and_then(|v| v.as_i64()).unwrap_or(0);
            tb.cmp(&ta)
        });

        let incoming_pending: usize = transactions
            .iter()
            .filter(|t| {
                t.get("direction").and_then(|v| v.as_str()) == Some("incoming")
                    && t.get("num_confirmations").and_then(|v| v.as_i64()) == Some(0)
            })
            .count();

        Ok(serde_json::json!({
            "transactions": transactions,
            "incoming_pending_count": incoming_pending,
        }))
    }

    /// Return LND connection info: base64url-encoded TLS cert and admin macaroon
    /// for building lndconnect:// URIs in the frontend.
    pub(crate) async fn handle_lnd_connect_info(&self) -> Result<serde_json::Value> {
        let cert_path = "/var/lib/archipelago/lnd/tls.cert";
        let macaroon_path =
            "/var/lib/archipelago/lnd/data/chain/bitcoin/mainnet/admin.macaroon";

        // Read and encode TLS cert (PEM → DER → base64url)
        let cert_pem = tokio::fs::read_to_string(cert_path)
            .await
            .context("Failed to read LND TLS certificate")?;
        let cert_der_b64: String = cert_pem
            .lines()
            .filter(|l| !l.starts_with("-----"))
            .collect();
        let cert_der = base64::engine::general_purpose::STANDARD
            .decode(&cert_der_b64)
            .context("Failed to decode PEM base64")?;
        let cert_b64url = base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(&cert_der);

        // Read and encode macaroon (binary → base64url)
        let macaroon_bytes = tokio::fs::read(macaroon_path)
            .await
            .context("Failed to read LND admin macaroon")?;
        let macaroon_b64url =
            base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(&macaroon_bytes);

        // Read Tor onion address — check system Tor path first, then legacy
        let tor_onion = {
            let mut onion = None;
            for path in &[
                "/var/lib/archipelago/tor-hostnames/lnd",
                "/var/lib/tor/hidden_service_lnd/hostname",
                "/var/lib/archipelago/tor/hidden_service_lnd/hostname",
            ] {
                if let Ok(addr) = tokio::fs::read_to_string(path).await {
                    let addr = addr.trim().to_string();
                    if addr.ends_with(".onion") {
                        onion = Some(addr);
                        break;
                    }
                }
                // Try sudo for system Tor dirs (owned by debian-tor, 0700)
                if let Ok(output) = tokio::process::Command::new("sudo")
                    .args(["cat", path])
                    .output()
                    .await
                {
                    if output.status.success() {
                        let addr = String::from_utf8_lossy(&output.stdout).trim().to_string();
                        if addr.ends_with(".onion") {
                            onion = Some(addr);
                            break;
                        }
                    }
                }
            }
            onion
        };

        Ok(serde_json::json!({
            "cert_base64url": cert_b64url,
            "macaroon_base64url": macaroon_b64url,
            "tor_onion": tor_onion,
            "rest_port": 8080,
            "grpc_port": 10009,
        }))
    }

    /// lnd.export-channel-backup — Export all channel static backups (SCB).
    /// Returns base64-encoded multi-channel backup that can restore channels on a new node.
    pub(super) async fn handle_lnd_export_channel_backup(&self) -> Result<serde_json::Value> {
        let macaroon_path = "/var/lib/archipelago/lnd/data/chain/bitcoin/mainnet/admin.macaroon";
        let macaroon_bytes = tokio::fs::read(macaroon_path)
            .await
            .context("Failed to read LND admin macaroon")?;
        let macaroon_hex = hex::encode(&macaroon_bytes);

        let cert_path = "/var/lib/archipelago/lnd/tls.cert";
        let client = reqwest::Client::builder()
            .danger_accept_invalid_certs(true)
            .timeout(std::time::Duration::from_secs(10))
            .build()
            .context("Failed to build HTTP client")?;

        let resp = client
            .get("https://127.0.0.1:8080/v1/channels/backup")
            .header("Grpc-Metadata-macaroon", &macaroon_hex)
            .send()
            .await
            .context("Failed to reach LND REST API")?;

        if !resp.status().is_success() {
            anyhow::bail!("LND returned {}", resp.status());
        }

        let data: serde_json::Value = resp.json().await.context("Invalid JSON from LND")?;

        // Extract the multi_chan_backup bytes
        let backup_b64 = data
            .get("multi_chan_backup")
            .and_then(|m| m.get("multi_chan_backup"))
            .and_then(|b| b.as_str())
            .unwrap_or("");

        Ok(serde_json::json!({
            "backup": backup_b64,
            "channel_count": data.get("multi_chan_backup")
                .and_then(|m| m.get("chan_points"))
                .and_then(|c| c.as_array())
                .map(|a| a.len())
                .unwrap_or(0),
            "timestamp": chrono::Utc::now().to_rfc3339(),
        }))
    }
}

// Channel types
#[derive(Debug, Serialize)]
struct ChannelInfo {
    chan_id: String,
    remote_pubkey: String,
    capacity: i64,
    local_balance: i64,
    remote_balance: i64,
    active: bool,
    status: String,
    channel_point: String,
}

#[derive(Debug, Serialize)]
struct ChannelListResult {
    channels: Vec<ChannelInfo>,
    total_inbound: i64,
    total_outbound: i64,
}

#[derive(Debug, Deserialize)]
struct LndListChannelsResponse {
    channels: Option<Vec<LndChannel>>,
}

#[derive(Debug, Deserialize)]
struct LndChannel {
    chan_id: Option<String>,
    remote_pubkey: Option<String>,
    capacity: Option<String>,
    local_balance: Option<String>,
    remote_balance: Option<String>,
    active: Option<bool>,
    channel_point: Option<String>,
}

#[derive(Debug, Deserialize, Default)]
struct LndPendingChannelsResponse {
    pending_open_channels: Option<Vec<LndPendingOpenChannel>>,
}

#[derive(Debug, Deserialize)]
struct LndPendingOpenChannel {
    channel: Option<LndPendingChannel>,
}

#[derive(Debug, Deserialize)]
struct LndPendingChannel {
    remote_node_pub: Option<String>,
    capacity: Option<String>,
    local_balance: Option<String>,
    remote_balance: Option<String>,
    channel_point: Option<String>,
}