/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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 androidx.room.integration.testapp.test;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

import android.support.test.filters.MediumTest;
import android.support.test.filters.SmallTest;
import android.support.test.runner.AndroidJUnit4;

import androidx.arch.core.executor.ArchTaskExecutor;
import androidx.arch.core.executor.TaskExecutor;
import androidx.room.EmptyResultSetException;
import androidx.room.integration.testapp.vo.Pet;
import androidx.room.integration.testapp.vo.User;
import androidx.room.integration.testapp.vo.UserAndAllPets;

import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import io.reactivex.Flowable;
import io.reactivex.Maybe;
import io.reactivex.Single;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Predicate;
import io.reactivex.observers.TestObserver;
import io.reactivex.schedulers.TestScheduler;
import io.reactivex.subscribers.TestSubscriber;

@SmallTest
@RunWith(AndroidJUnit4.class)
public class RxJava2Test extends TestDatabaseTest {

    private TestScheduler mTestScheduler;

    @Before
    public void setupSchedulers() {
        mTestScheduler = new TestScheduler();
        mTestScheduler.start();
        ArchTaskExecutor.getInstance().setDelegate(new TaskExecutor() {
            @Override
            public void executeOnDiskIO(Runnable runnable) {
                mTestScheduler.scheduleDirect(runnable);
            }

            @Override
            public void postToMainThread(Runnable runnable) {
                Assert.fail("no main thread in this test");
            }

            @Override
            public boolean isMainThread() {
                return false;
            }
        });
    }

    @After
    public void clearSchedulers() {
        mTestScheduler.shutdown();
        ArchTaskExecutor.getInstance().setDelegate(null);
    }

    private void drain() throws InterruptedException {
        mTestScheduler.triggerActions();
    }

    @Test
    public void maybeUser_Empty() throws InterruptedException {
        TestObserver<User> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.maybeUserById(3).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        testObserver.assertNoValues();
        disposable.dispose();
    }

    @Test
    public void maybeUser_WithData() throws InterruptedException {
        User user = TestUtil.createUser(3);
        mUserDao.insert(user);
        TestObserver<User> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.maybeUserById(3).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        testObserver.assertValue(user);

        disposable.dispose();
    }

    @Test
    public void maybeUsers_EmptyList() throws InterruptedException {
        TestObserver<List<User>> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.maybeUsersByIds(3, 5, 7).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        testObserver.assertValue(Collections.<User>emptyList());
        disposable.dispose();
    }

    @Test
    public void maybeUsers_WithValue() throws InterruptedException {
        User[] users = TestUtil.createUsersArray(3, 5);
        mUserDao.insertAll(users);
        TestObserver<List<User>> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.maybeUsersByIds(3, 5, 7).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        // since this is a clean db, it is ok to rely on the order for the test.
        testObserver.assertValue(Arrays.asList(users));
        disposable.dispose();
    }

    @Test
    public void maybeUsers_keepMaybeReference() throws InterruptedException {
        User[] users = TestUtil.createUsersArray(1, 2);
        mUserDao.insertAll(users);
        TestObserver<User> testObserver1 = new TestObserver<>();
        Maybe<User> maybe1 = mUserDao.maybeUserById(1);
        Disposable disposable1 = maybe1.observeOn(mTestScheduler)
                .subscribeWith(testObserver1);
        drain();
        testObserver1.assertComplete();
        // since this is a clean db, it is ok to rely on the order for the test.
        testObserver1.assertValue(users[0]);

        TestObserver<User> testObserver2 = new TestObserver<>();
        Maybe<User> maybe2 = mUserDao.maybeUserById(2);
        Disposable disposable2 = maybe2.observeOn(mTestScheduler)
                .subscribeWith(testObserver2);
        drain();
        testObserver2.assertComplete();
        // since this is a clean db, it is ok to rely on the order for the test.
        testObserver2.assertValue(users[1]);

        TestObserver<User> testObserver3 = new TestObserver<>();

        Disposable disposable3 = maybe1.observeOn(mTestScheduler)
                .subscribeWith(testObserver3);
        drain();
        testObserver3.assertComplete();
        // since this is a clean db, it is ok to rely on the order for the test.
        testObserver3.assertValue(users[0]);

        disposable1.dispose();
        disposable2.dispose();
        disposable3.dispose();
    }

    @Test
    public void singleUser_Empty() throws InterruptedException {
        TestObserver<User> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.singleUserById(3).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        // figure out which error we should dispatch
        testObserver.assertError(EmptyResultSetException.class);
        testObserver.assertNoValues();
        disposable.dispose();
    }

    @Test
    public void singleUser_WithData() throws InterruptedException {
        User user = TestUtil.createUser(3);
        mUserDao.insert(user);
        TestObserver<User> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.singleUserById(3).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        testObserver.assertValue(user);

        disposable.dispose();
    }

    @Test
    public void singleUsers_EmptyList() throws InterruptedException {
        TestObserver<List<User>> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.singleUsersByIds(3, 5, 7).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        testObserver.assertValue(Collections.<User>emptyList());
        disposable.dispose();
    }

    @Test
    public void singleUsers_WithValue() throws InterruptedException {
        User[] users = TestUtil.createUsersArray(3, 5);
        mUserDao.insertAll(users);
        TestObserver<List<User>> testObserver = new TestObserver<>();
        Disposable disposable = mUserDao.singleUsersByIds(3, 5, 7).observeOn(mTestScheduler)
                .subscribeWith(testObserver);
        drain();
        testObserver.assertComplete();
        // since this is a clean db, it is ok to rely on the order for the test.
        testObserver.assertValue(Arrays.asList(users));
        disposable.dispose();
    }

    @Test
    public void singleUser_keepSingleReference() throws InterruptedException {
        User[] users = TestUtil.createUsersArray(1, 2);
        mUserDao.insertAll(users);
        TestObserver<User> testObserver1 = new TestObserver<>();
        Single<User> userSingle1 = mUserDao.singleUserById(1);
        Disposable disposable1 = userSingle1.observeOn(mTestScheduler)
                .subscribeWith(testObserver1);
        drain();
        testObserver1.assertComplete();
        testObserver1.assertValue(users[0]);
        disposable1.dispose();

        // how get single for 2
        TestObserver<User> testObserver2 = new TestObserver<>();
        Single<User> userSingle2 = mUserDao.singleUserById(2);
        Disposable disposable2 = userSingle2.observeOn(mTestScheduler)
                .subscribeWith(testObserver2);
        drain();
        testObserver2.assertComplete();
        testObserver2.assertValue(users[1]);
        disposable2.dispose();

        // now re-use the first single
        TestObserver<User> testObserver3 = new TestObserver<>();
        Disposable disposable3 = userSingle1.observeOn(mTestScheduler)
                .subscribeWith(testObserver3);
        drain();
        testObserver3.assertComplete();
        testObserver3.assertValue(users[0]);
        disposable3.dispose();
    }


    @Test
    public void observeOnce() throws InterruptedException {
        User user = TestUtil.createUser(3);
        mUserDao.insert(user);
        drain();
        TestSubscriber<User> consumer = new TestSubscriber<>();
        Disposable disposable = mUserDao.flowableUserById(3).subscribeWith(consumer);
        drain();
        consumer.assertValue(user);
        disposable.dispose();
    }

    @Test
    public void observeChangeAndDispose() throws InterruptedException {
        User user = TestUtil.createUser(3);
        mUserDao.insert(user);
        drain();
        TestSubscriber<User> consumer = new TestSubscriber<>();
        Disposable disposable = mUserDao.flowableUserById(3).observeOn(mTestScheduler)
                .subscribeWith(consumer);
        drain();
        assertThat(consumer.values().get(0), is(user));
        user.setName("rxy");
        mUserDao.insertOrReplace(user);
        drain();
        User next = consumer.values().get(1);
        assertThat(next, is(user));
        disposable.dispose();
        user.setName("foo");
        mUserDao.insertOrReplace(user);
        drain();
        assertThat(consumer.valueCount(), is(2));
    }

    @Test
    @MediumTest
    public void observeEmpty() throws InterruptedException {
        TestSubscriber<User> consumer = new TestSubscriber<>();
        Disposable disposable = mUserDao.flowableUserById(3).observeOn(mTestScheduler)
                .subscribeWith(consumer);
        drain();
        consumer.assertNoValues();
        User user = TestUtil.createUser(3);
        mUserDao.insert(user);
        drain();
        assertThat(consumer.values().get(0), is(user));
        disposable.dispose();
        user.setAge(88);
        mUserDao.insertOrReplace(user);
        drain();
        assertThat(consumer.valueCount(), is(1));
    }

    @Test
    public void observeFlowable_keepReference() throws InterruptedException {
        User[] users = TestUtil.createUsersArray(1, 2);
        mUserDao.insertAll(users);
        drain();

        TestSubscriber<User> consumer1 = new TestSubscriber<>();
        Flowable<User> flowable1 = mUserDao.flowableUserById(1);
        Disposable disposable1 = flowable1.subscribeWith(consumer1);
        drain();
        consumer1.assertValue(users[0]);

        TestSubscriber<User> consumer2 = new TestSubscriber<>();
        Disposable disposable2 = mUserDao.flowableUserById(2).subscribeWith(consumer2);
        drain();
        consumer2.assertValue(users[1]);

        TestSubscriber<User> consumer3 = new TestSubscriber<>();
        Disposable disposable3 = flowable1.subscribeWith(consumer3);
        drain();
        consumer3.assertValue(users[0]);

        disposable1.dispose();
        disposable2.dispose();
        disposable3.dispose();
    }

    @Test
    public void flowableCountUsers() throws InterruptedException {
        TestSubscriber<Integer> consumer = new TestSubscriber<>();
        mUserDao.flowableCountUsers()
                .observeOn(mTestScheduler)
                .subscribe(consumer);
        drain();
        assertThat(consumer.values().get(0), is(0));
        mUserDao.insertAll(TestUtil.createUsersArray(1, 3, 4, 6));
        drain();
        assertThat(consumer.values().get(1), is(4));
        mUserDao.deleteByUids(3, 7);
        drain();
        assertThat(consumer.values().get(2), is(3));
        mUserDao.deleteByUids(101);
        drain();
        assertThat(consumer.valueCount(), is(3));
    }

    @Test
    @MediumTest
    public void publisherCountUsers() throws InterruptedException {
        TestSubscriber<Integer> subscriber = new TestSubscriber<>();
        mUserDao.publisherCountUsers().subscribe(subscriber);
        drain();
        subscriber.assertSubscribed();
        subscriber.request(2);
        drain();
        subscriber.assertValue(0);
        mUserDao.insert(TestUtil.createUser(2));
        drain();
        subscriber.assertValues(0, 1);
        subscriber.cancel();
        subscriber.assertNoErrors();
    }

    @Test
    public void flowableWithRelation() throws InterruptedException {
        final TestSubscriber<UserAndAllPets> subscriber = new TestSubscriber<>();

        mUserPetDao.flowableUserWithPets(3).subscribe(subscriber);
        drain();
        subscriber.assertSubscribed();

        drain();
        subscriber.assertNoValues();

        final User user = TestUtil.createUser(3);
        mUserDao.insert(user);
        drain();
        subscriber.assertValue(new Predicate<UserAndAllPets>() {
            @Override
            public boolean test(UserAndAllPets userAndAllPets) throws Exception {
                return userAndAllPets.user.equals(user);
            }
        });
        subscriber.assertValueCount(1);
        final Pet[] pets = TestUtil.createPetsForUser(3, 1, 2);
        mPetDao.insertAll(pets);
        drain();
        subscriber.assertValueAt(1, new Predicate<UserAndAllPets>() {
            @Override
            public boolean test(UserAndAllPets userAndAllPets) throws Exception {
                return userAndAllPets.user.equals(user)
                        && userAndAllPets.pets.equals(Arrays.asList(pets));
            }
        });
    }

    @Test
    public void flowable_updateInTransaction() throws InterruptedException {
        // When subscribing to the emissions of the user
        final TestSubscriber<User> userTestSubscriber = mUserDao
                .flowableUserById(3)
                .observeOn(mTestScheduler)
                .test();
        drain();
        userTestSubscriber.assertValueCount(0);

        // When inserting a new user in the data source
        mDatabase.beginTransaction();
        try {
            mUserDao.insert(TestUtil.createUser(3));
            mDatabase.setTransactionSuccessful();

        } finally {
            mDatabase.endTransaction();
        }
        drain();
        userTestSubscriber.assertValueCount(1);
    }
}