// Copyright 2016 The Domain Registry Authors. 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.

package google.registry.testing;

import static com.google.common.truth.Truth.assert_;
import static google.registry.testing.DatastoreHelper.persistSimpleResources;
import static google.registry.util.ResourceUtils.readResourceUtf8;
import static java.nio.charset.StandardCharsets.UTF_8;
import static org.json.XML.toJSONObject;

import com.google.appengine.tools.development.testing.LocalDatastoreServiceTestConfig;
import com.google.appengine.tools.development.testing.LocalModulesServiceTestConfig;
import com.google.appengine.tools.development.testing.LocalServiceTestConfig;
import com.google.appengine.tools.development.testing.LocalServiceTestHelper;
import com.google.appengine.tools.development.testing.LocalTaskQueueTestConfig;
import com.google.appengine.tools.development.testing.LocalURLFetchServiceTestConfig;
import com.google.appengine.tools.development.testing.LocalUserServiceTestConfig;
import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import com.google.common.io.Files;
import com.googlecode.objectify.ObjectifyFilter;
import google.registry.model.ofy.ObjectifyService;
import google.registry.model.registrar.Registrar;
import google.registry.model.registrar.Registrar.State;
import google.registry.model.registrar.RegistrarAddress;
import google.registry.model.registrar.RegistrarContact;
import google.registry.util.Clock;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.logging.LogManager;
import javax.annotation.Nullable;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.junit.rules.ExternalResource;
import org.junit.rules.RuleChain;
import org.junit.rules.TemporaryFolder;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;

/**
 * JUnit Rule for managing the App Engine testing environment.
 *
 * <p>Generally you'll want to configure the environment using only the services you need (because
 * each service is expensive to create).
 *
 * <p>This rule also resets global Objectify for the current thread.
 *
 * @see org.junit.rules.ExternalResource
 */
public final class AppEngineRule extends ExternalResource {

  public static final String NEW_REGISTRAR_GAE_USER_ID = "666";
  public static final String THE_REGISTRAR_GAE_USER_ID = "31337";

  /**
   * The GAE testing library requires queue.xml to be a file, not a resource in a jar, so we read it
   * in here and write it to a temporary file later.
   */
  private static final String QUEUE_XML =
      readResourceUtf8("google/registry/env/common/default/WEB-INF/queue.xml");

  /** A parsed version of the indexes used in the prod code. */
  private static final Set<String> MANUAL_INDEXES = getIndexXmlStrings(
      readResourceUtf8(
          "google/registry/env/common/default/WEB-INF/datastore-indexes.xml"));

  private static final String LOGGING_PROPERTIES =
      readResourceUtf8(AppEngineRule.class, "logging.properties");

  private LocalServiceTestHelper helper;

  /** A rule-within-a-rule to provide a temporary folder for AppEngineRule's internal temp files. */
  private TemporaryFolder temporaryFolder = new TemporaryFolder();

  private boolean withDatastore;
  private boolean withLocalModules;
  private boolean withTaskQueue;
  private boolean withUserService;
  private boolean withUrlFetch;
  private Clock clock;

  private String taskQueueXml;
  private UserInfo userInfo;

  /** Builder for {@link AppEngineRule}. */
  public static class Builder {

    private AppEngineRule rule = new AppEngineRule();

    /** Turn on the datastore service. */
    public Builder withDatastore() {
      rule.withDatastore = true;
      return this;
    }

    /** Turn on the use of local modules. */
    public Builder withLocalModules() {
      rule.withLocalModules = true;
      return this;
    }


    /** Turn on the task queue service. */
    public Builder withTaskQueue() {
      return withTaskQueue(QUEUE_XML);
    }

    /** Turn on the task queue service with a specified set of queues. */
    public Builder withTaskQueue(String taskQueueXml) {
      rule.withTaskQueue = true;
      rule.taskQueueXml = taskQueueXml;
      return this;
    }

    /** Turn on the URL Fetch service. */
    public Builder withUrlFetch() {
      rule.withUrlFetch = true;
      return this;
    }

    public Builder withClock(Clock clock) {
      rule.clock = clock;
      return this;
    }

    public Builder withUserService(UserInfo userInfo) {
      rule.withUserService = true;
      rule.userInfo = userInfo;
      return this;
    }

    public AppEngineRule build() {
      return rule;
    }
  }

  public static Builder builder() {
    return new Builder();
  }

  private static Registrar.Builder makeRegistrarCommon() {
    return new Registrar.Builder()
        .setType(Registrar.Type.REAL)
        .setState(State.ACTIVE)
        .setEmailAddress("new.registrar@example.com")
        .setIcannReferralEmail("lol@sloth.test")
        .setInternationalizedAddress(new RegistrarAddress.Builder()
            .setStreet(ImmutableList.of("123 Example Boulevard"))
            .setCity("Williamsburg")
            .setState("NY")
            .setZip("11211")
            .setCountryCode("US")
            .build())
        .setLocalizedAddress(new RegistrarAddress.Builder()
            .setStreet(ImmutableList.of("123 Example B\u0151ulevard"))
            .setCity("Williamsburg")
            .setState("NY")
            .setZip("11211")
            .setCountryCode("US")
            .build())
        .setPhoneNumber("+1.3334445555")
        .setPhonePasscode("12345")
        .setContactsRequireSyncing(true);
  }

  /** Public factory for first Registrar to allow comparison against stored value in unit tests. */
  public static Registrar makeRegistrar1() {
    return makeRegistrarCommon()
        .setClientIdentifier("NewRegistrar")
        .setRegistrarName("New Registrar")
        .setIanaIdentifier(8L)
        .setPassword("foo-BAR2")
        .setPhoneNumber("+1.3334445555")
        .setPhonePasscode("12345")
        .build();
  }

  /** Public factory for second Registrar to allow comparison against stored value in unit tests. */
  public static Registrar makeRegistrar2() {
    return makeRegistrarCommon()
        .setClientIdentifier("TheRegistrar")
        .setRegistrarName("The Registrar")
        .setIanaIdentifier(1L)
        .setPassword("password2")
        .setPhoneNumber("+1.2223334444")
        .setPhonePasscode("22222")
        .build();
  }

  /**
   * Public factory for first RegistrarContact to allow comparison
   * against stored value in unit tests.
   */
  public static RegistrarContact makeRegistrarContact1() {
    return new RegistrarContact.Builder()
        .setParent(makeRegistrar1())
        .setName("Jane Doe")
        .setVisibleInWhoisAsAdmin(true)
        .setVisibleInWhoisAsTech(false)
        .setEmailAddress("janedoe@theregistrar.com")
        .setPhoneNumber("+1.1234567890")
        .setTypes(ImmutableSet.of(RegistrarContact.Type.ADMIN))
        .setGaeUserId(NEW_REGISTRAR_GAE_USER_ID)
        .build();
  }

  /**
   * Public factory for second RegistrarContact to allow comparison
   * against stored value in unit tests.
   */
  public static RegistrarContact makeRegistrarContact2() {
    return new RegistrarContact.Builder()
        .setParent(makeRegistrar2())
        .setName("John Doe")
        .setEmailAddress("johndoe@theregistrar.com")
        .setPhoneNumber("+1.1234567890")
        .setTypes(ImmutableSet.of(RegistrarContact.Type.ADMIN))
        .setGaeUserId(THE_REGISTRAR_GAE_USER_ID)
        .build();
  }

  /** Hack to make sure AppEngineRule is always wrapped in a TemporaryFolder rule. */
  @Override
  public Statement apply(Statement base, Description description) {
    return RuleChain.outerRule(temporaryFolder).around(new TestRule() {
      @Override
      public Statement apply(Statement base, Description description) {
        return AppEngineRule.super.apply(base, null);
      }}).apply(base, description);
  }

  @Override
  protected void before() throws IOException {
    setupLogging();
    Set<LocalServiceTestConfig> configs = new HashSet<>();
    if (withUrlFetch) {
      configs.add(new LocalURLFetchServiceTestConfig());
    }
    if (withDatastore) {
      configs.add(new LocalDatastoreServiceTestConfig()
          // We need to set this to allow cross entity group transactions.
          .setApplyAllHighRepJobPolicy()
          // This causes unit tests to write a file containing any indexes the test required. We
          // can use that file below to make sure we have the right indexes in our prod code.
          .setNoIndexAutoGen(false));
      // This forces app engine to write the generated indexes to a usable location.
      System.setProperty("appengine.generated.dir", temporaryFolder.getRoot().getAbsolutePath());
    }
    if (withLocalModules) {
      configs.add(new LocalModulesServiceTestConfig()
          .addBasicScalingModuleVersion("default", "1", 1)
          .addBasicScalingModuleVersion("tools", "1", 1)
          .addBasicScalingModuleVersion("backend", "1", 1));
    }
    if (withTaskQueue) {
      File queueFile = temporaryFolder.newFile("queue.xml");
      Files.write(taskQueueXml, queueFile, UTF_8);
      configs.add(new LocalTaskQueueTestConfig()
          .setQueueXmlPath(queueFile.getAbsolutePath()));
    }
    if (withUserService) {
      configs.add(new LocalUserServiceTestConfig());
    }

    helper = new LocalServiceTestHelper(configs.toArray(new LocalServiceTestConfig[]{}));

    if (withUserService) {
      // Set top-level properties on LocalServiceTestConfig for user login.
      helper.setEnvIsLoggedIn(userInfo.isLoggedIn())
          // This envAttributes thing is the only way to set userId.
          // see https://code.google.com/p/googleappengine/issues/detail?id=3579
          .setEnvAttributes(ImmutableMap.<String, Object>of(
              "com.google.appengine.api.users.UserService.user_id_key", userInfo.gaeUserId()))
          .setEnvAuthDomain(userInfo.authDomain())
          .setEnvEmail(userInfo.email())
          .setEnvIsAdmin(userInfo.isAdmin());
    }

    if (clock != null) {
      helper.setClock(new com.google.appengine.tools.development.Clock() {
        @Override
        public long getCurrentTime() {
          return clock.nowUtc().getMillis();
        }
      });
    }

    if (withLocalModules) {
      helper.setEnvInstance("0");
    }

    helper.setUp();

    if (withDatastore) {
      ObjectifyService.initOfy();
      // Reset id allocation in ObjectifyService so that ids are deterministic in tests.
      ObjectifyService.resetNextTestId();
      loadInitialData();
    }
  }

  @Override
  protected void after() {
    // Resets Objectify. Although it would seem more obvious to do this at the start of a request
    // instead of at the end, this is more consistent with what ObjectifyFilter does in real code.
    ObjectifyFilter.complete();
    helper.tearDown();
    helper = null;
    // Test that the datastore didn't need any indexes we don't have listed in our index file.
    try {
      Set<String> autoIndexes = getIndexXmlStrings(Files.toString(
          new File(temporaryFolder.getRoot(), "datastore-indexes-auto.xml"), UTF_8));
      Set<String> missingIndexes = Sets.difference(autoIndexes, MANUAL_INDEXES);
      if (!missingIndexes.isEmpty()) {
        assert_().fail("Missing indexes:\n%s", Joiner.on('\n').join(missingIndexes));
      }
    } catch (IOException e) {  // This is fine; no indexes were written.
    }
  }

  /** Install {@code testing/logging.properties} so logging is less noisy. */
  private static void setupLogging() throws IOException {
    LogManager.getLogManager()
        .readConfiguration(new ByteArrayInputStream(LOGGING_PROPERTIES.getBytes(UTF_8)));
  }

  /** Read a datastore index file, and parse the indexes into individual strings. */
  private static Set<String> getIndexXmlStrings(String indexFile) {
    ImmutableSet.Builder<String> builder = new ImmutableSet.Builder<>();
    try {
      // To normalize the indexes, we are going to pass them through JSON and then rewrite the xml.
      JSONObject datastoreIndexes = new JSONObject();
      Object indexes = toJSONObject(indexFile).get("datastore-indexes");
      if (indexes instanceof JSONObject) {
        datastoreIndexes = (JSONObject) indexes;
      }
      for (JSONObject index : getJsonAsArray(datastoreIndexes.opt("datastore-index"))) {
        builder.add(getIndexXmlString(index));
      }
    } catch (JSONException e) {
      throw new RuntimeException(e);
    }
    return builder.build();
  }

  /**
   * Normalize a value from JSONObject that represents zero, one, or many values. If there were zero
   * values this will be null or an empty JSONArray, depending on how the field was represented in
   * JSON. If there was one value, the object passed in will be that value. If there were more than
   * one values, the object will be a JSONArray containing those values. We will return a list in
   * all cases.
   */
  private static List<JSONObject> getJsonAsArray(@Nullable Object object) throws JSONException {
    ImmutableList.Builder<JSONObject> builder = new ImmutableList.Builder<>();
    if (object instanceof JSONArray) {
      for (int i = 0; i < ((JSONArray) object).length(); ++i) {
        builder.add(((JSONArray) object).getJSONObject(i));
      }
    } else if (object instanceof JSONObject){
      // When there's only a single entry it won't be wrapped in an array.
      builder.add((JSONObject) object);
    }
    return builder.build();
  }

  /** Turn a JSON representation of an index into xml. */
  private static String getIndexXmlString(JSONObject source) throws JSONException {
    StringBuilder builder = new StringBuilder();
    builder.append(String.format(
        "<datastore-index kind=\"%s\" ancestor=\"%s\" source=\"manual\">\n",
        source.getString("kind"),
        source.get("ancestor").toString()));
    for (JSONObject property : getJsonAsArray(source.get("property"))) {
      builder.append(String.format(
          "  <property name=\"%s\" direction=\"%s\"/>\n",
          property.getString("name"),
          property.getString("direction")));
    }
    return builder.append("</datastore-index>").toString();
  }

  /** Create some fake registrars. */
  public static void loadInitialData() {
    persistSimpleResources(
        ImmutableList.of(
            makeRegistrar1(), makeRegistrarContact1(), makeRegistrar2(), makeRegistrarContact2()));
  }
}