Native Bitcoin.
Programmable collateral.

module example::loan;

use example::provider::LoanProvider;
use sui::coin::Coin;
use hashi::btc::BTC;
use
0x44f838219cf67b058f3b37907b655f226153c18e33dfcd0da559a844fea9b1c1::usdsui::USDSUI;

public struct Collateral has key, store {

    id: UID,

    collateral: Coin<BTC>,

    ltv_ratio_bps: u64,

    owner: address,
}



public struct LoanTerms has key, store {

    id: UID,

    ltv_ratio_bps: u16,

    amount_collateralized: u64,

    amount_borrowed: u64,
}

public fun collateralize(

    provider: &mut LoanProvider,

    collateral: Coin<BTC>,

    ltv_ratio_bps: u16,

    ctx: &mut TxContext,
): (Coin<USDSUI>, LoanTerms) {

    let collateral = Collateral {

        id: object::new(ctx),

        collateral,

        ltv_ratio_bps,

        owner: ctx.sender(),

    };



   provider.originate_loan(collateral)
}



public fun payoff(

    provider: &mut LoanProvider,

    loan: LoanTerms,

    payoff: Coin<USDSUI>,

    ctx: &mut TxContext,
): Coin<BTC> {

    assert!(loan.amount_borrowed ==
payoff.value());
    provider.payoff_loan(loan, payoff, ctx)

}