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use crate::miniscript::{Descriptor, DescriptorPublicKey};
use bitcoin::hashes::{hash_newtype, sha256, Hash};
use bitcoin::Amount;
hash_newtype! {
/// Represents the unique ID of a descriptor.
///
/// This is useful for having a fixed-length unique representation of a descriptor,
/// in particular, we use it to persist application state changes related to the
/// descriptor without having to re-write the whole descriptor each time.
///
pub struct DescriptorId(pub sha256::Hash);
}
/// A trait to extend the functionality of a miniscript descriptor.
pub trait DescriptorExt {
/// Returns the minimum [`Amount`] at which an output is broadcast-able.
/// Panics if the descriptor wildcard is hardened.
fn dust_value(&self) -> Amount;
/// Returns the descriptor ID, calculated as the sha256 hash of the spk derived from the
/// descriptor at index 0.
fn descriptor_id(&self) -> DescriptorId;
}
impl DescriptorExt for Descriptor<DescriptorPublicKey> {
fn dust_value(&self) -> Amount {
self.at_derivation_index(0)
.expect("descriptor can't have hardened derivation")
.script_pubkey()
.minimal_non_dust()
}
fn descriptor_id(&self) -> DescriptorId {
let spk = self.at_derivation_index(0).unwrap().script_pubkey();
DescriptorId(sha256::Hash::hash(spk.as_bytes()))
}
}