// file: crates/ksp-offchain-transport-lib/unit_tests/decimal.rs
// version: 1

#[test]
fn decimal_normalizes_fractional_and_scientific_forms_without_f64() -> ksp_core_lib::Result<()> {
    let cases = [
        ("123.4500", "123.45", 12_345_u128, 2_u8),
        ("1.2345e2", "123.45", 12_345, 2),
        ("12345e-2", "123.45", 12_345, 2),
        ("1e3", "1000", 1_000, 0),
        ("1e-3", "0.001", 1, 3),
    ];
    for (source, expected, coefficient, scale) in cases {
        let value = match crate::PriceDecimal::parse(source) {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        assert_eq!(value.to_canonical_string(), expected);
        assert_eq!(value.coefficient(), coefficient);
        assert_eq!(value.scale(), scale);
    }
    return std::result::Result::Ok(());
}

#[test]
fn decimal_rejects_zero_negative_nonfinite_excessive_scale_and_overflow() {
    let invalid = ["0", "0.000", "-1", "+1", "NaN", "inf", "1e-19", "1e129", "340282366920938463463374607431768211456", " 1", "1 ", ".1", "1."];
    for source in invalid {
        let result = crate::PriceDecimal::parse(source);
        assert!(result.is_err());
        if let std::result::Result::Err(error) = result {
            assert_eq!(error.code(), crate::ERROR_CODE_PRICE_DECIMAL_INVALID);
        }
    }
}

#[test]
fn decimal_serde_is_canonical_string_and_round_trips_exactly() -> ksp_core_lib::Result<()> {
    let value = match crate::PriceDecimal::parse("123.4500") {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    let encoded = match serde_json::to_string(&value) {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(_) => {
            return std::result::Result::Err(ksp_core_lib::Error::new(crate::ERROR_CODE_PRICE_DECIMAL_INVALID, "test serialization failed"));
        },
    };
    assert_eq!(encoded, "\"123.45\"");
    let decoded: crate::PriceDecimal = match serde_json::from_str(encoded.as_str()) {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(_) => {
            return std::result::Result::Err(ksp_core_lib::Error::new(crate::ERROR_CODE_PRICE_DECIMAL_INVALID, "test deserialization failed"));
        },
    };
    assert_eq!(decoded, value);
    assert!(serde_json::from_str::<crate::PriceDecimal>("123.45").is_err());
    return std::result::Result::Ok(());
}