bft-crdt-experiment/side-node/src/keys/bitcoin.rs

use bdk::{
    bitcoin::Network,
    database::MemoryDatabase,
    keys::{
        bip39::{Language, Mnemonic, WordCount},
        DerivableKey, ExtendedKey, GeneratableKey, GeneratedKey,
    },
    miniscript,
    template::Bip84,
    KeychainKind, Wallet,
};

use std::{
    fs::{self, File},
    io::Write,
    path::PathBuf,
};

pub fn make_mnemonic() -> String {
    let mnemonic: GeneratedKey<_, miniscript::Segwitv0> =
        Mnemonic::generate((WordCount::Words12, Language::English)).unwrap();
    mnemonic.to_string()
}

pub(crate) fn write(mnemonic_path: &PathBuf) -> Result<(), std::io::Error> {
    let mnemonic = make_mnemonic();
    let mut file = File::create(mnemonic_path)?;
    println!("mnemonic: {mnemonic}");
    file.write(mnemonic.as_bytes())?;

    Ok(())
}

/// Creates a Signet Bitcoin descriptor wallet from a mnemonic
pub fn create_wallet(mnemonic_words: String) -> anyhow::Result<Wallet<MemoryDatabase>> {
    let mnemonic = Mnemonic::parse(mnemonic_words).unwrap();

    // Generate the extended key
    let xkey: ExtendedKey = mnemonic.into_extended_key()?;

    // Get private key from the extended key
    let xprv = xkey.into_xprv(Network::Signet).unwrap();

    // Create a BDK wallet using BIP 84 descriptor ("m/84h/1h/0h/0" and "m/84h/1h/0h/1")
    let wallet = Wallet::new(
        Bip84(xprv, KeychainKind::External),
        Some(Bip84(xprv, KeychainKind::Internal)),
        Network::Testnet,
        MemoryDatabase::default(),
    )?;

    Ok(wallet)
}

pub(crate) fn load_from_file(side_dir: &PathBuf) -> anyhow::Result<Wallet<MemoryDatabase>> {
    let mnemonic_path = crate::utils::side_paths(side_dir.clone()).1; // TODO: this tuple stinks
    let mnemonic_words = fs::read_to_string(mnemonic_path).expect("couldn't read bitcoin key file");
    println!("Creating wallet from mnemonic: {mnemonic_words}");
    create_wallet(mnemonic_words)
}