niko_trust_gui/src/book.rs

//! Local address book: memorable labels for trust1… addresses.
//!
//! Entries map an address string to a free-form label ("Niko"); persistence
//! lives in the vault file. The display helper renders known addresses as
//! `Label (trust1qz8jr…7tx6w)` and unknown ones as just the shortened address.

use std::collections::BTreeMap;

#[derive(Debug, Default)]
pub struct AddressBook {
    entries: BTreeMap<String, String>,
}

impl AddressBook {
    pub fn from_entries(entries: BTreeMap<String, String>) -> AddressBook {
        AddressBook { entries }
    }

    pub fn entries(&self) -> &BTreeMap<String, String> {
        &self.entries
    }

    pub fn label_of(&self, addr: &str) -> Option<&str> {
        self.entries.get(addr).map(|s| s.as_str())
    }

    /// Sets (or clears, when `label` is blank) the label for an address.
    /// Returns true when the map changed.
    pub fn set_label(&mut self, addr: &str, label: &str) -> bool {
        let label = label.trim();
        if label.is_empty() {
            self.entries.remove(addr).is_some()
        } else {
            match self.entries.get(addr) {
                Some(cur) if cur == label => false,
                _ => {
                    self.entries.insert(addr.to_string(), label.to_string());
                    true
                }
            }
        }
    }

    /// Compact display form: `Niko (trust1qz8jr…7tx6w)` when known, otherwise
    /// just the shortened address.
    pub fn display(&self, addr: &str) -> String {
        match self.label_of(addr) {
            Some(l) => format!("{l} ({})", short_addr(addr)),
            None => short_addr(addr),
        }
    }
}

/// Bech32 addresses are long; keep a compact form for the UI.
pub fn short_addr(a: &str) -> String {
    if a.len() <= 20 {
        a.to_string()
    } else {
        format!("{}…{}", &a[..10], &a[a.len() - 6..])
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn display_known_and_unknown() {
        let mut b = AddressBook::default();
        let addr = "trust1qz8jrkwdnqscwrvptu69z6ntd2dp092s0fk25ayq94qlzsx649dszg7tx6w";
        assert_eq!(b.display(addr), short_addr(addr));

        assert!(b.set_label(addr, "Niko"));
        assert_eq!(b.display(addr), format!("Niko ({})", short_addr(addr)));
        assert_eq!(b.label_of(addr), Some("Niko"));

        // Blank label clears the entry.
        b.set_label(addr, "   ");
        assert_eq!(b.display(addr), short_addr(addr));
        // Clearing a missing entry reports no change.
        assert!(!b.set_label(addr, ""));
    }
}