nostr-sdk 0.45.0

use std::collections::{HashMap, HashSet};

use nostr::filter::Filter;
use nostr::types::RelayUrl;

use super::req_target::{InnerReqTarget, ReqTarget};
use crate::client::url::RelayUrlArg;
use crate::client::{Client, Error};
use crate::pool::RelayPool;

// Build the targets for a REQ
pub(super) async fn build_targets(
    client: &Client,
    target: ReqTarget<'_>,
) -> Result<HashMap<RelayUrl, Vec<Filter>>, Error> {
    // Build targets
    match client.gossip() {
        Some(gossip) => match target.into_inner() {
            // Gossip is configured and we need to break down filters before subscribing
            InnerReqTarget::Auto(filters) => {
                client.gossip_break_down_filters(gossip, filters).await
            }
            // The request is already manual, skip gossip
            InnerReqTarget::Manual(target) => Ok(convert_filters_arg_vec_to_map(target)?),
        },
        // No gossip configured: directly use the target
        None => Ok(convert_filters_arg_to_targets(client.pool(), target).await?),
    }
}

async fn make_targets_from_filter_list(
    pool: &RelayPool,
    filters: Vec<Filter>,
) -> HashMap<RelayUrl, Vec<Filter>> {
    let urls: HashSet<RelayUrl> = pool.read_relay_urls().await;
    urls.into_iter().map(|u| (u, filters.clone())).collect()
}

async fn convert_filters_arg_to_targets(
    pool: &RelayPool,
    target: ReqTarget<'_>,
) -> Result<HashMap<RelayUrl, Vec<Filter>>, Error> {
    match target.into_inner() {
        InnerReqTarget::Auto(filters) => Ok(make_targets_from_filter_list(pool, filters).await),
        InnerReqTarget::Manual(targets) => convert_filters_arg_vec_to_map(targets),
    }
}

pub(super) fn convert_filters_arg_vec_to_map(
    targeted: Vec<(RelayUrlArg<'_>, Vec<Filter>)>,
) -> Result<HashMap<RelayUrl, Vec<Filter>>, Error> {
    let mut map: HashMap<RelayUrl, Vec<Filter>> = HashMap::with_capacity(targeted.len());
    for (url_arg, filters) in targeted {
        let url: RelayUrl = url_arg.try_into_relay_url()?.into_owned();
        map.insert(url, filters);
    }
    Ok(map)
}