use super::funejson::Value;
use super::money_amount::{assert_same_currency, money_from_value, Money};

/// -1, 0 or 1, comparing two amounts of the same currency.
///
/// Refuses mixed currencies: which of GBP 10 and EUR 10 is larger depends on a
/// rate, and a comparison that ignores the currency sorts a list into nonsense.
///
/// # Panics
/// Panics if the two amounts are in different currencies.
pub fn compare_money(a: &Money, b: &Money) -> i64 {
    assert_same_currency(a, b);
    match a.minor.cmp(&b.minor) {
        std::cmp::Ordering::Less => -1,
        std::cmp::Ordering::Equal => 0,
        std::cmp::Ordering::Greater => 1,
    }
}

pub fn fune_vector(args: &[Value]) -> Value {
    Value::Int(compare_money(
        &money_from_value(&args[0]),
        &money_from_value(&args[1]),
    ))
}