feat: New config relays command to set the default fallbacks relays

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

src/cli/commands/config/relays.rs

@@ -0,0 +1,53 @@
+// 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 clap::Args;
+use nostr::types::RelayUrl;
+
+use crate::{
+    cli::{CliOptions, traits::CommandRunner},
+    error::N34Result,
+};
+
+#[derive(Args, Debug)]
+pub struct RelaysArgs {
+    /// List of relay URLs to append to fallback relays. If empty, removes all
+    /// fallback relays.
+    relays:          Vec<RelayUrl>,
+    /// Replace existing fallback relays instead of appending new ones.
+    #[arg(long = "override")]
+    override_relays: bool,
+}
+
+impl CommandRunner for RelaysArgs {
+    async fn run(self, mut options: CliOptions) -> N34Result<()> {
+        // FIXME: The signer is not required here
+
+        if self.relays.is_empty() {
+            options.config.fallback_relays = None;
+        } else if self.override_relays {
+            options.config.fallback_relays = Some(self.relays);
+        } else {
+            let mut relays = options.config.fallback_relays.clone().unwrap_or_default();
+            relays.extend(self.relays);
+            relays.sort_unstable();
+            relays.dedup();
+            options.config.fallback_relays = Some(relays);
+        }
+
+        options.config.dump()
+    }
+}