/*
 *   Copyright (c) 2022 R3BL LLC
 *   All rights reserved.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

//! Integration tests for the `lazy` module.

use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};

use r3bl_rs_utils::utils::LazyMemoValues;
use r3bl_rs_utils_core::{assert_eq2, debug};

#[test]
fn test_lazy() {
    // These are copied in the closure below.
    let arc_atomic_count = AtomicUsize::new(0);
    let mut a_variable = 123;
    let mut a_flag = false;

    debug!(a_variable);
    debug!(a_flag);

    let mut generate_value_fn = LazyMemoValues::new(|it| {
        arc_atomic_count.fetch_add(1, SeqCst);
        a_variable = 12;
        a_flag = true;
        a_variable + it
    });

    assert_eq2!(arc_atomic_count.load(SeqCst), 0);
    assert_eq2!(generate_value_fn.get_ref(&1), &13);
    assert_eq2!(arc_atomic_count.load(SeqCst), 1);
    assert_eq2!(generate_value_fn.get_ref(&1), &13); // Won't regenerate the value.
    assert_eq2!(arc_atomic_count.load(SeqCst), 1); // Doesn't change.

    assert_eq2!(generate_value_fn.get_ref(&2), &14);
    assert_eq2!(arc_atomic_count.load(SeqCst), 2);
    assert_eq2!(generate_value_fn.get_ref(&2), &14);
    assert_eq2!(generate_value_fn.get_copy(&2), 14);

    assert_eq2!(a_variable, 12);
    assert!(a_flag);
}