c-lightning-pruning-plugin 0.1.1

use std::borrow::Cow;

use failure::Error;
use serde_json::Value;
use tokio::net::UnixStream;

use crate::rpc::{make_socket_req, JsonRpcV2Id, RpcParams, RpcReq};

#[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
pub struct LightningInfo {
    pub blockheight: u64,
}

pub async fn prune(
    socket: &mut UnixStream,
    bitcoin_req: &reqwest::RequestBuilder,
    rescan: u64,
) -> Result<(), Error> {
    // fetch scanned block height from c-lightning
    let res = make_socket_req(
        socket,
        RpcReq {
            id: Some(JsonRpcV2Id::Num(0.into())),
            jsonrpc: Default::default(),
            method: Cow::Borrowed("getinfo"),
            params: RpcParams::ByPosition(Vec::new()),
        },
    )
    .await?
    .result
    .res()?;
    let res: LightningInfo = serde_json::from_value(res)?;
    if res.blockheight < rescan + 1 {
        return Ok(()); // don't want to prune to negative height
    }
    let prune_height = res.blockheight - rescan - 1;
    log::info!("pruning bitcoin to {}", prune_height);
    // run "pruneblockchain" against bitcoind
    let res = bitcoin_req
        .try_clone()
        .ok_or_else(|| failure::format_err!("cannot clone request"))?
        .json(&RpcReq {
            id: Some(JsonRpcV2Id::Num(0.into())),
            jsonrpc: Default::default(),
            method: Cow::Borrowed("pruneblockchain"),
            params: RpcParams::ByPosition(vec![Value::Number(prune_height.into())]),
        })
        .send()
        .await?;
    match res.error_for_status_ref() {
        Ok(_) => (),
        Err(e) => return Err(failure::format_err!("{}: {:?}", e, res.text().await)),
    }

    Ok(())
}