feat: Support relays and naddrs sets

This commit introduces support for 'sets', a feature that simplifies
referencing multiple relays or naddrs with a single word.

Sets are stored in the config directory under `n34` as `config.toml` in
`TOML` format. The config path follows the `$XDG_CONFIG_HOME` standard,
defaulting to `$HOME/.config` if unset.

The `n34 sets` command allows managing sets, adding, removing, updating,
or displaying them. When using the main `--relays` flag, a set name can
be provided to automatically expand its relays (an error occurs if the
set contains no relays). Similarly, any command accepting naddrs can
reference a set to extract its naddrs.

Sets can also be merged by updating a set while specifying another
set in `--repo` merges their naddrs, while `--set-relays` merges their
relays. Removal follows the same pattern.

Signed-off-by: Awiteb <a@4rs.nl>

src/cli/types.rs

@@ -0,0 +1,194 @@
+// n34 - A CLI to interact with NIP-34 and other stuff related to codes in nostr
+// Copyright (C) 2025 Awiteb <a@4rs.nl>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://gnu.org/licenses/gpl-3.0.html>.
+
+use std::str::FromStr;
+
+use nostr::{
+    event::Kind,
+    nips::{self, nip01::Coordinate, nip19::Nip19Coordinate},
+    types::RelayUrl,
+};
+use tokio::runtime::Handle;
+
+use super::{RepoRelaySetsExt, parsers};
+use crate::{
+    cli::RepoRelaySet,
+    error::{N34Error, N34Result},
+};
+
+/// Either a NIP-19 coordinate (naddr) or a named set.
+#[derive(Debug, Clone)]
+pub enum NaddrOrSet {
+    /// NIP-19 coordinate.
+    Naddr(Nip19Coordinate),
+    /// Name of a set (may not exist).
+    Set(String),
+}
+
+/// Either relay URL or a named set.
+#[derive(Debug, Clone)]
+pub enum RelayOrSet {
+    /// Relay URL.
+    Relay(RelayUrl),
+    /// Name of a set (may not exist).
+    Set(String),
+}
+
+impl NaddrOrSet {
+    /// Returns the naddr if `Naddr` or try to get the relays from the set.
+    /// Returns error if the set naddrs are empty or the set not found.
+    pub fn get_naddrs(self, sets: &[RepoRelaySet]) -> N34Result<Vec<Nip19Coordinate>> {
+        match self {
+            Self::Naddr(nip19_coordinate) => Ok(vec![nip19_coordinate]),
+            Self::Set(name) => {
+                let set = sets
+                    .get_set(&name)
+                    .map_err(|_| N34Error::InvalidNaddrArg(name.clone()))?;
+                if set.naddrs.is_empty() {
+                    Err(N34Error::EmptySetNaddrs(name))
+                } else {
+                    Ok(Vec::from_iter(set.naddrs.clone()))
+                }
+            }
+        }
+    }
+}
+
+
+impl RelayOrSet {
+    /// Returns the relay if `Relay` or try to get the relays from the set.
+    /// Returns error if the set relays are empty or the set not found
+    pub fn get_relays(self, sets: &[RepoRelaySet]) -> N34Result<Vec<RelayUrl>> {
+        match self {
+            Self::Relay(relay) => Ok(vec![relay]),
+            Self::Set(name) => {
+                let set = sets.get_set(&name)?;
+                if set.relays.is_empty() {
+                    Err(N34Error::EmptySetRelays(name))
+                } else {
+                    Ok(Vec::from_iter(set.relays.clone()))
+                }
+            }
+        }
+    }
+}
+
+impl FromStr for NaddrOrSet {
+    type Err = String;
+
+    /// Parses a Git repository address which can be either:
+    /// - A bech32-encoded naddr (e.g. "naddr1...") for Git repository
+    ///   announcements (kind 30617)
+    /// - A NIP-05 identifier with repository ID (e.g. "4rs.nl/n34" or
+    ///   "_@4rs.nl/n34")
+    /// - A set name.
+    ///
+    /// Returns an error for invalid formats, failed bech32 decoding, wrong
+    /// event kind.
+    fn from_str(naddr_or_set: &str) -> Result<Self, Self::Err> {
+        let naddr_or_set = naddr_or_set.trim();
+
+        if naddr_or_set.contains("/") {
+            let (nip5, repo_id) = naddr_or_set.split_once("/").expect("There is a `/`");
+            parse_nip5_repo(nip5, repo_id)
+        } else if naddr_or_set.starts_with("naddr1") || naddr_or_set.starts_with("nostr:naddr1") {
+            parsers::parse_repo_naddr(naddr_or_set.trim_start_matches("nostr:")).map(Self::Naddr)
+        } else {
+            Ok(Self::Set(naddr_or_set.to_owned()))
+        }
+    }
+}
+
+impl FromStr for RelayOrSet {
+    type Err = String;
+
+    /// Parse a string into a relay URL or a set name.
+    /// If the string is a valid URL (e.g., "wss://example.com"), it's treated
+    /// as a relay URL. Otherwise, it's treated as a set name, and its
+    /// associated relays will be merged.
+    fn from_str(relay_or_set: &str) -> Result<Self, Self::Err> {
+        let relay_or_set = relay_or_set.trim();
+
+        if relay_or_set.starts_with("wss://") {
+            RelayUrl::from_str(relay_or_set)
+                .map_err(|err| err.to_string())
+                .map(Self::Relay)
+        } else {
+            Ok(Self::Set(relay_or_set.to_owned()))
+        }
+    }
+}
+
+fn parse_nip5_repo(nip5: &str, repo_id: &str) -> Result<NaddrOrSet, String> {
+    let (username, domain) = nip5.split_once("@").unwrap_or(("_", nip5));
+
+    let nip5_profile = tokio::task::block_in_place(|| {
+        Handle::current().block_on(async {
+            nips::nip05::profile(format!("{username}@{domain}"), None)
+                .await
+                .map_err(|err| err.to_string())
+        })
+    })?;
+
+    Ok(NaddrOrSet::Naddr(
+        Nip19Coordinate::new(
+            Coordinate::new(Kind::GitRepoAnnouncement, nip5_profile.public_key).identifier(repo_id),
+            nip5_profile.relays,
+        )
+        .expect("The relays is `RelayUrl`"),
+    ))
+}
+
+#[easy_ext::ext(NaddrOrSetVecExt)]
+impl Vec<NaddrOrSet> {
+    /// Converts this vector of [`NaddrOrSet`] into a flat vector of
+    /// [`Nip19Coordinates`] using the given sets.
+    pub fn flat_naddrs(self, sets: &[RepoRelaySet]) -> N34Result<Vec<Nip19Coordinate>> {
+        self.into_iter()
+            .map(|n| n.get_naddrs(sets))
+            .try_fold(Vec::new(), |mut acc, item| {
+                acc.extend(item?);
+                Ok(acc)
+            })
+    }
+}
+
+#[easy_ext::ext(RelayOrSetVecExt)]
+impl Vec<RelayOrSet> {
+    /// Converts this vector of [`RelayOrSet`] into a flat vector of
+    /// [`RelayUrl`] using the given sets.
+    pub fn flat_relays(self, sets: &[RepoRelaySet]) -> N34Result<Vec<RelayUrl>> {
+        self.into_iter()
+            .map(|n| n.get_relays(sets))
+            .try_fold(Vec::new(), |mut acc, item| {
+                acc.extend(item?);
+                Ok(acc)
+            })
+    }
+}
+
+
+#[easy_ext::ext(OptionNaddrOrSetVecExt)]
+impl Option<Vec<NaddrOrSet>> {
+    /// Converts this vector of [`NaddrOrSet`] into a flat vector of
+    /// [`Nip19Coordinates`] using the given sets.
+    pub fn flat_naddrs(&self, sets: &[RepoRelaySet]) -> N34Result<Option<Vec<Nip19Coordinate>>> {
+        // Clones self here to simplify command code
+        self.clone()
+            .map(|naddrs| naddrs.flat_naddrs(sets))
+            .transpose()
+    }
+}