fix(cdk-cli): parse --unit consistently and scope balance by currency

Signed-off-by: b-l-u-e <8102260+blue@users.noreply.github.com>

Author: b-l-u-e

crates/cdk-cli/src/main.rs

@@ -56,9 +56,10 @@ struct Cli {
     /// NWS Proxy
     #[arg(short, long)]
     proxy: Option<Url>,
-    /// Currency unit to use for the wallet
-    #[arg(short, long, default_value = "sat")]
-    unit: String,
+    /// Currency unit (default `sat` when omitted). Standard: sat, msat, usd, eur, auth; other values are custom.
+    /// `cdk --unit usd balance` and `cdk balance --unit usd` are equivalent. `cdk --unit balance` parses `balance` as the unit value, not the subcommand.
+    #[arg(short, long, global = true)]
+    unit: Option<String>,
     /// NpubCash API URL
     #[cfg(feature = "npubcash")]
     #[arg(long, default_value = "https://npubx.cash")]
@@ -215,9 +216,10 @@ async fn main() -> Result<()> {
     };
     let seed = mnemonic.to_seed_normalized("");
 
-    // Parse currency unit from args
-    let currency_unit = CurrencyUnit::from_str(&args.unit)
-        .unwrap_or_else(|_| CurrencyUnit::Custom(args.unit.clone()));
+    let currency_unit = match &args.unit {
+        Some(s) => utils::parse_cli_currency_unit(s)?,
+        None => CurrencyUnit::Sat,
+    };
 
     // Create WalletRepository using builder pattern
     let wallet_repository = {
@@ -252,7 +254,9 @@ async fn main() -> Result<()> {
         Commands::DecodeToken(sub_command_args) => {
             sub_commands::decode_token::decode_token(sub_command_args)
         }
-        Commands::Balance => sub_commands::balance::balance(&wallet_repository).await,
+        Commands::Balance => {
+            sub_commands::balance::balance(&wallet_repository, &currency_unit).await
+        }
         Commands::Melt(sub_command_args) => {
             sub_commands::melt::pay(&wallet_repository, sub_command_args, &currency_unit).await
         }

crates/cdk-cli/src/sub_commands/balance.rs

@@ -7,9 +7,13 @@ use cdk::wallet::WalletRepository;
 use cdk::Amount;
 use cdk_common::wallet::WalletKey;
 
-pub async fn balance(wallet_repository: &WalletRepository) -> Result<()> {
-    // Show individual mint balances
-    let mint_balances = mint_balances(wallet_repository).await?;
+/// Print balances for each mint for the given [`CurrencyUnit`] (e.g. sat from `cdk balance`, or
+/// `--unit usd` for USD-only wallets).
+pub async fn balance(
+    wallet_repository: &WalletRepository,
+    filter_unit: &CurrencyUnit,
+) -> Result<()> {
+    let mint_balances = mint_balances(wallet_repository, filter_unit).await?;
 
     if !mint_balances.is_empty() {
         // Aggregate totals per currency unit
@@ -29,13 +33,16 @@ pub async fn balance(wallet_repository: &WalletRepository) -> Result<()> {
                 println!("  {} {}", total, unit);
             }
         }
+    } else {
+        println!("No balance for unit {filter_unit}.");
     }
 
     Ok(())
 }
 
 pub async fn mint_balances(
     wallet_repository: &WalletRepository,
+    filter_unit: &CurrencyUnit,
 ) -> Result<Vec<(MintUrl, CurrencyUnit, Amount)>> {
     let wallets = wallet_repository.get_balances().await?;
 
@@ -44,6 +51,7 @@ pub async fn mint_balances(
     for (i, (wallet_key, amount)) in wallets
         .iter()
         .filter(|(_, a)| a > &&Amount::ZERO)
+        .filter(|(wk, _)| wk.unit == *filter_unit)
         .enumerate()
     {
         let WalletKey { mint_url, unit } = wallet_key.clone();

crates/cdk-cli/src/utils.rs

@@ -1,11 +1,38 @@
 use std::io::{self, Write};
 use std::str::FromStr;
 
-use anyhow::Result;
+use anyhow::{bail, Result};
 use cdk::mint_url::MintUrl;
 use cdk::nuts::CurrencyUnit;
 use cdk::wallet::WalletRepository;
 
+/// Parse global `--unit`: trim, plural aliases (`sats`→`sat`, …), then [`CurrencyUnit::from_str`].
+pub fn parse_cli_currency_unit(s: &str) -> Result<CurrencyUnit> {
+    let trimmed = s.trim();
+    if trimmed.is_empty() {
+        bail!("Currency unit must not be empty (omit `--unit` to use the default `sat`)");
+    }
+
+    if trimmed.eq_ignore_ascii_case("satt") {
+        bail!("Unknown currency unit '{trimmed}'. Did you mean 'sat'?");
+    }
+
+    let normalized: &str = match trimmed.to_ascii_lowercase().as_str() {
+        "sats" => "sat",
+        "msats" => "msat",
+        "usds" => "usd",
+        "eurs" => "eur",
+        "auths" => "auth",
+        _ => trimmed,
+    };
+
+    let unit = CurrencyUnit::from_str(normalized).map_err(|e| anyhow::anyhow!(e))?;
+    if let CurrencyUnit::Custom(ref name) = unit {
+        tracing::info!("Using custom currency unit '{name}' (not one of sat, msat, usd, eur, auth)");
+    }
+    Ok(unit)
+}
+
 /// Helper function to get user input with a prompt
 pub fn get_user_input(prompt: &str) -> Result<String> {
     println!("{prompt}");