#[cfg(feature = "ffi")]
#[test]
fn ffi_bmi_and_patient() {
    let mut out: f32 = 0.0;
    let rc = medicallib_rust::ffi::medicallib_bmi(70.0, 1.75, &mut out as *mut f32);
    assert_eq!(rc, medicallib_rust::ffi::ML_OK);
    assert!(out > 10.0);

    use std::ffi::CString;
    let id = CString::new("ffi-test").unwrap();
    let p = medicallib_rust::ffi::ml_patient_new(id.as_ptr());
    assert!(!p.is_null());
    let _ = medicallib_rust::ffi::ml_patient_update(p, 0.1);
    let s = medicallib_rust::ffi::ml_patient_summary(p);
    assert!(!s.is_null());
    medicallib_rust::ffi::ml_string_free(s);
    medicallib_rust::ffi::ml_patient_free(p);
}

#[cfg(feature = "ffi")]
#[test]
fn ffi_errors() {
    // Null out pointer arguments should error gracefully
    let rc = medicallib_rust::ffi::medicallib_bmi(70.0, 1.75, std::ptr::null_mut());
    assert_eq!(rc, medicallib_rust::ffi::ML_EINVAL);
    let p = medicallib_rust::ffi::ml_patient_new(std::ptr::null());
    assert!(p.is_null());
    // Summary with null patient returns null
    let s = medicallib_rust::ffi::ml_patient_summary(std::ptr::null());
    assert!(s.is_null());
}

#[cfg(feature = "ffi")]
#[test]
fn ffi_bloodstream_metrics() {
    use medicallib_rust::ffi::*;
    use std::ffi::CString;

    let id = CString::new("ffi-blood").unwrap();
    let p = ml_patient_new(id.as_ptr());
    assert!(!p.is_null());

    let mut metrics = std::mem::MaybeUninit::<MLBloodstreamMetrics>::uninit();
    assert_eq!(ml_patient_update(p, 0.5), ML_OK);
    let rc = ml_patient_bloodstream_metrics(p, metrics.as_mut_ptr());
    assert_eq!(rc, ML_OK);
    let metrics = unsafe { metrics.assume_init() };
    assert!(metrics.oncotic_pressure_mm_hg > 15.0);
    assert!(metrics.rbc_mature_fraction > 0.4);
    ml_patient_free(p);
}