/*
 * 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.rxjava3.internal.operators.observable;

import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.*;

import org.junit.Test;

import io.reactivex.rxjava3.core.*;
import io.reactivex.rxjava3.exceptions.TestException;
import io.reactivex.rxjava3.functions.Supplier;
import io.reactivex.rxjava3.testsupport.TestHelper;

@SuppressWarnings("unchecked")
public class ObservableDeferTest extends RxJavaTest {

    @Test
    public void defer() throws Throwable {

        Supplier<Observable<String>> factory = mock(Supplier.class);

        Observable<String> firstObservable = Observable.just("one", "two");
        Observable<String> secondObservable = Observable.just("three", "four");
        when(factory.get()).thenReturn(firstObservable, secondObservable);

        Observable<String> deferred = Observable.defer(factory);

        verifyNoInteractions(factory);

        Observer<String> firstObserver = TestHelper.mockObserver();
        deferred.subscribe(firstObserver);

        verify(factory, times(1)).get();
        verify(firstObserver, times(1)).onNext("one");
        verify(firstObserver, times(1)).onNext("two");
        verify(firstObserver, times(0)).onNext("three");
        verify(firstObserver, times(0)).onNext("four");
        verify(firstObserver, times(1)).onComplete();

        Observer<String> secondObserver = TestHelper.mockObserver();
        deferred.subscribe(secondObserver);

        verify(factory, times(2)).get();
        verify(secondObserver, times(0)).onNext("one");
        verify(secondObserver, times(0)).onNext("two");
        verify(secondObserver, times(1)).onNext("three");
        verify(secondObserver, times(1)).onNext("four");
        verify(secondObserver, times(1)).onComplete();

    }

    @Test
    public void deferFunctionThrows() throws Throwable {
        Supplier<Observable<String>> factory = mock(Supplier.class);

        when(factory.get()).thenThrow(new TestException());

        Observable<String> result = Observable.defer(factory);

        Observer<String> o = TestHelper.mockObserver();

        result.subscribe(o);

        verify(o).onError(any(TestException.class));
        verify(o, never()).onNext(any(String.class));
        verify(o, never()).onComplete();
    }
}
