/*
 * Copyright (C) 2024 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 com.android.server.pm;

import static android.os.Process.myUid;

import static com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn;

import static com.google.common.truth.Truth.assertThat;

import static org.junit.Assert.assertThrows;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.ArgumentMatchers.anyLong;
import static org.mockito.ArgumentMatchers.argThat;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.ArgumentMatchers.nullable;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import android.app.ActivityManager;
import android.app.AppOpsManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.pm.PackageInstaller;
import android.os.Environment;
import android.os.FileUtils;
import android.os.Handler;
import android.os.PermissionEnforcer;
import android.os.UserHandle;
import android.platform.test.annotations.Presubmit;
import android.util.ArrayMap;

import androidx.test.platform.app.InstrumentationRegistry;
import androidx.test.runner.AndroidJUnit4;

import com.android.server.IoThread;
import com.android.server.LocalServices;
import com.android.server.SystemServiceManager;
import com.android.server.pm.verify.developer.DeveloperVerifierController;

import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import java.io.File;

@Presubmit
@RunWith(AndroidJUnit4.class)
public class PackageInstallerServiceTest {
    private @Mock PermissionEnforcer mMockPermissionEnforcer;
    private @Mock ActivityManager mMockActivityManager;
    private @Mock AppOpsManager mAppOpsManager;
    private @Mock SystemServiceManager mMockSystemServiceManager;
    private @Mock DeveloperVerifierController mMockDeveloperVerifierController;
    private @Mock File mMockeFile;
    private String mPackageName;
    private PackageManagerService mPms;
    private @Mock Computer mMockSnapshot;
    private @Mock Handler mMockHandler;
    private File mTestDir;
    private final PackageManagerServiceTestParams mTestParams =
            new PackageManagerServiceTestParams();
    private static final int TEST_USER_ID = 10;
    private static final int TEST_USER_ID_2 = 20;
    private static final int TEST_USER_ID_3 = 30;
    private static final int TEST_USER_ID_4 = 40;

    @Rule
    public final MockSystemRule rule = new MockSystemRule();

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);
        rule.system().stageNominalSystemState();
        mPackageName = this.getClass().getPackageName();
        mTestParams.packages = new ArrayMap<>();
        // Basic mocks to support session creation
        when(rule.mocks().getContext().getSystemService(Context.PERMISSION_ENFORCER_SERVICE))
                .thenReturn(mMockPermissionEnforcer);
        when(rule.mocks().getContext().getSystemService(ActivityManager.class))
                .thenReturn(mMockActivityManager);
        when(rule.mocks().getContext().getSystemService(AppOpsManager.class))
                .thenReturn(mAppOpsManager);
        doReturn(mMockeFile).when(() -> Environment.getDataAppDirectory(nullable(String.class)));
        doReturn(mMockeFile).when(
                () -> Environment.getDataStagingDirectory(nullable(String.class)));
        doReturn(mMockSystemServiceManager).when(
                () -> LocalServices.getService(SystemServiceManager.class));
        // Run scheduled write tasks right away
        doReturn(mMockHandler).when(IoThread::getHandler);
        when(mMockHandler.post(any(Runnable.class))).thenAnswer(
                i -> {
                    ((Runnable) i.getArguments()[0]).run();
                    return true;
                });
        doReturn(mMockDeveloperVerifierController).when(
                () -> DeveloperVerifierController.getInstance(any(Context.class),
                        any(Handler.class), argThat(componentName
                                -> componentName.getPackageName().equals(mPackageName)
                ))
        );
        // Test specific environment setup
        doReturn(mPackageName).when(mMockDeveloperVerifierController).getVerifierPackageName();
        mPms = spy(new PackageManagerService(rule.mocks().getInjector(), mTestParams));
        doReturn(false).when(mPms).isUserRestricted(anyInt(), nullable(String.class));
        doReturn(mMockSnapshot).when(mPms).snapshotComputer();
        doReturn(myUid()).when(mMockSnapshot).getPackageUidInternal(
                eq(mPackageName), anyLong(), anyInt(), anyInt());
        // Create a test file for read/write of mSessionsFile
        mTestDir = new File(InstrumentationRegistry.getInstrumentation().getTargetContext()
                .getFilesDir(), "testDir");
        assertThat(mTestDir.mkdirs()).isTrue();
        doReturn(mTestDir).when(Environment::getDataSystemDirectory);
    }

    @After
    public void tearDown() {
        if (mTestDir != null) {
            // Clean up test dir to remove persisted user files.
            FileUtils.deleteContentsAndDir(mTestDir);
        }
    }

    @Test
    public void testVerificationPolicyPerUser() {
        doReturn(new int[] {UserHandle.USER_SYSTEM, TEST_USER_ID, TEST_USER_ID_2})
                .when(mPms.mUserManager).getUserIds();
        final PackageInstallerService service = new PackageInstallerService(
                rule.mocks().getContext(), mPms, null,
                new ComponentName(mPackageName, this.getClass().getName()));
        service.systemReady();
        final int defaultPolicy = service.getDeveloperVerificationPolicy(
                /* userId= */ UserHandle.USER_SYSTEM);
        assertThat(defaultPolicy).isAtLeast(PackageInstaller.DEVELOPER_VERIFICATION_POLICY_NONE);
        assertThat(service.getDeveloperVerificationPolicy(TEST_USER_ID)).isEqualTo(defaultPolicy);
        assertThat(service.getDeveloperVerificationPolicy(TEST_USER_ID_2)).isEqualTo(defaultPolicy);
        assertThat(service.setDeveloperVerificationPolicy(
                /* policy= */ PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_CLOSED,
                /* userId= */ UserHandle.USER_SYSTEM)).isTrue();
        // Test with a non-existing user
        final int newUserId = TEST_USER_ID_3;
        assertThrows(IllegalStateException.class, () -> service.getDeveloperVerificationPolicy(
                /* userId= */ newUserId));
        assertThrows(IllegalStateException.class,
                () -> service.setDeveloperVerificationPolicy(
                /* policy= */ PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_CLOSED,
                /* userId= */ newUserId));
        // Add a user
        service.onUserAdded(newUserId);
        assertThat(service.getDeveloperVerificationPolicy(newUserId)).isEqualTo(defaultPolicy);
        assertThat(service.setDeveloperVerificationPolicy(
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_WARN, newUserId)
        ).isTrue();
        assertThat(service.getDeveloperVerificationPolicy(newUserId)).isEqualTo(
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_WARN);
        // Remove a user
        service.onUserRemoved(newUserId);
        assertThrows(IllegalStateException.class, () -> service.getDeveloperVerificationPolicy(
                /* userId= */ newUserId));
        assertThrows(
                IllegalStateException.class,
                () -> service.setDeveloperVerificationPolicy(
                        /* policy= */
                        PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_CLOSED,
                        /* userId= */ newUserId));
    }

    @Test
    public void testWriteAndReadVerificationPolicyPerUser() {
        doReturn(new int[] {UserHandle.USER_SYSTEM, TEST_USER_ID, TEST_USER_ID_2})
                .when(mPms.mUserManager).getUserIds();
        final PackageInstallerService service = new PackageInstallerService(
                rule.mocks().getContext(), mPms, null,
                new ComponentName(mPackageName, this.getClass().getName()));
        service.systemReady();
        final int defaultPolicy = service.getDeveloperVerificationPolicy(
                /* userId= */ UserHandle.USER_SYSTEM);
        // Modify the policy for each user
        final int policyForSystemUser =
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_CLOSED;
        final int policyForTestUser =
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_WARN;
        final int policyForTestUser2 =
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_OPEN;
        assertThat(service.setDeveloperVerificationPolicy(
                /* policy= */ policyForSystemUser,
                /* userId= */ UserHandle.USER_SYSTEM)).isTrue();
        assertThat(service.setDeveloperVerificationPolicy(
                /* policy= */ policyForTestUser,
                /* userId= */ TEST_USER_ID)).isTrue();
        assertThat(service.setDeveloperVerificationPolicy(
                /* policy= */ policyForTestUser2,
                /* userId= */ TEST_USER_ID_2)).isTrue();
        // systemReady and Each policy change above should have triggered a write to the test file
        // but since the write in systemReady is done immediately in the main thread of
        // PackageInstallerService and doesn't go through the handler of the IO thread, we don't
        // have the chance to verify that here.
        verify(mMockHandler, times(3)).post(any(Runnable.class));
        // Mimic a reboot by creating a new service instance with the latest policy for each user
        // loaded from the test file
        final PackageInstallerService service2 = new PackageInstallerService(
                rule.mocks().getContext(), mPms, null,
                new ComponentName(mPackageName, this.getClass().getName()));
        service2.systemReady();
        assertThat(service2.getDeveloperVerificationPolicy(UserHandle.USER_SYSTEM)).isEqualTo(
                policyForSystemUser);
        assertThat(service2.getDeveloperVerificationPolicy(TEST_USER_ID)).isEqualTo(
                policyForTestUser);
        assertThat(service2.getDeveloperVerificationPolicy(TEST_USER_ID_2)).isEqualTo(
                policyForTestUser2);
    }

    // Mimic a system where it initially has 2 users, then 1 is removed and a new one is added
    // on reboot. Then all are removed and a different one is added on reboot. Test that the
    // per-user developer verification policy is correctly set.
    @Test
    public void testCleanUpVerificationPolicyPerUser() {
        doReturn(new int[] {UserHandle.USER_SYSTEM, TEST_USER_ID})
                .when(mPms.mUserManager).getUserIds();
        PackageInstallerService service = new PackageInstallerService(
                rule.mocks().getContext(), mPms, null,
                new ComponentName(mPackageName, this.getClass().getName()));
        service.systemReady();
        final int defaultPolicy = service.getDeveloperVerificationPolicy(
                /* userId= */ UserHandle.USER_SYSTEM);
        // Modify the policy for each user
        final int policyForSystemUser =
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_CLOSED;
        final int policyForTestUser =
                PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_WARN;
        assertThat(service.setDeveloperVerificationPolicy(
                /* policy= */ policyForSystemUser,
                /* userId= */ UserHandle.USER_SYSTEM)).isTrue();
        assertThat(service.setDeveloperVerificationPolicy(
                /* policy= */ policyForTestUser,
                /* userId= */ TEST_USER_ID)).isTrue();
        // Mimic a reboot by creating a new service instance. The policy for the deleted user
        // should not exist, and the policy for the new user should be the default policy.
        // And previously set policy should be preserved on the remaining user.
        PackageManagerService mPms2 = spy(new PackageManagerService(rule.mocks().getInjector(),
                mTestParams));
        doReturn(new int[] {UserHandle.USER_SYSTEM, TEST_USER_ID_2})
                .when(mPms2.mUserManager).getUserIds();
        final PackageInstallerService service2 = new PackageInstallerService(
                rule.mocks().getContext(), mPms2, null,
                new ComponentName(mPackageName, this.getClass().getName()));
        service2.systemReady();
        assertThat(service2.getDeveloperVerificationPolicy(UserHandle.USER_SYSTEM)).isEqualTo(
                policyForSystemUser);
        assertThrows(IllegalStateException.class, () -> service2.getDeveloperVerificationPolicy(
                TEST_USER_ID));
        assertThat(service2.getDeveloperVerificationPolicy(TEST_USER_ID_2)).isEqualTo(
                defaultPolicy);
        // Mimic another reboot by creating a new service instance. The policy for the deleted users
        // should not exist, and the policy for the new users should be the default policy.
        PackageManagerService mPms3 = spy(new PackageManagerService(rule.mocks().getInjector(),
                mTestParams));
        doReturn(new int[] {TEST_USER_ID_3, TEST_USER_ID_4})
                .when(mPms3.mUserManager).getUserIds();
        final PackageInstallerService service3 = new PackageInstallerService(
                rule.mocks().getContext(), mPms3, null,
                new ComponentName(mPackageName, this.getClass().getName()));
        service3.systemReady();
        assertThrows(IllegalStateException.class, () -> service3.getDeveloperVerificationPolicy(
                UserHandle.USER_SYSTEM));
        assertThrows(IllegalStateException.class, () -> service3.getDeveloperVerificationPolicy(
                TEST_USER_ID_2));
        assertThat(service3.getDeveloperVerificationPolicy(TEST_USER_ID_3)).isEqualTo(
                defaultPolicy);
        assertThat(service3.getDeveloperVerificationPolicy(TEST_USER_ID_4)).isEqualTo(
                defaultPolicy);
    }

    @Test
    public void testVerifierIsNullThrowsException() {
        doReturn(mMockDeveloperVerifierController).when(
                () -> DeveloperVerifierController.getInstance(any(), any(), eq(null))
        );
        when(mMockDeveloperVerifierController.getVerifierPackageName()).thenReturn(null);
        PackageInstallerService service = new PackageInstallerService(
                rule.mocks().getContext(), mPms, null, null);
        // When there is no verifier specified by the system, no one can change the policy.
        assertThrows(SecurityException.class,
                () -> service.setDeveloperVerificationPolicy(
                /* policy= */ PackageInstaller.DEVELOPER_VERIFICATION_POLICY_BLOCK_FAIL_CLOSED,
                /* userId= */ UserHandle.USER_SYSTEM));
    }
}