/*
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * 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.
 */

package io.reactivex.rxjava4.internal.operators.observable;

import java.lang.ref.WeakReference;

import org.junit.*;

import io.reactivex.rxjava4.core.*;
import io.reactivex.rxjava4.exceptions.TestException;
import io.reactivex.rxjava4.functions.Function;
import io.reactivex.rxjava4.observers.TestObserver;
import io.reactivex.rxjava4.testsupport.TestHelper;

public class ObservableDetachTest extends RxJavaTest {

    Object o;

    @Test
    public void just() throws Exception {
        o = new Object();

        WeakReference<Object> wr = new WeakReference<>(o);

        TestObserver<Object> to = new TestObserver<>();

        Observable.just(o).count().toObservable().onTerminateDetach().subscribe(to);

        to.assertValue(1L);
        to.assertComplete();
        to.assertNoErrors();

        o = null;

        System.gc();
        Thread.sleep(200);

        Assert.assertNull("Object retained!", wr.get());

    }

    @Test
    public void error() {
        TestObserver<Object> to = new TestObserver<>();

        Observable.error(new TestException()).onTerminateDetach().subscribe(to);

        to.assertNoValues();
        to.assertError(TestException.class);
        to.assertNotComplete();
    }

    @Test
    public void empty() {
        TestObserver<Object> to = new TestObserver<>();

        Observable.empty().onTerminateDetach().subscribe(to);

        to.assertNoValues();
        to.assertNoErrors();
        to.assertComplete();
    }

    @Test
    public void range() {
        TestObserver<Object> to = new TestObserver<>();

        Observable.range(1, 1000).onTerminateDetach().subscribe(to);

        to.assertValueCount(1000);
        to.assertNoErrors();
        to.assertComplete();
    }

    @Test
    public void justUnsubscribed() throws Exception {
        o = new Object();

        WeakReference<Object> wr = new WeakReference<>(o);

        TestObserver<Long> to = Observable.just(o).count().toObservable().onTerminateDetach().test();

        o = null;
        to.dispose();

        System.gc();
        Thread.sleep(200);

        Assert.assertNull("Object retained!", wr.get());

    }

    @Test
    public void dispose() {
        TestHelper.checkDisposed(Observable.never().onTerminateDetach());
    }

    @Test
    public void doubleOnSubscribe() {
        TestHelper.checkDoubleOnSubscribeObservable(new Function<Observable<Object>, ObservableSource<Object>>() {
            @Override
            public ObservableSource<Object> apply(Observable<Object> o) throws Exception {
                return o.onTerminateDetach();
            }
        });
    }
}
