// Copyright (C) 2014 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.google.gerrit.pgm.init;

import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.base.Strings;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.entities.Account;
import com.google.gerrit.entities.GroupReference;
import com.google.gerrit.entities.InternalGroup;
import com.google.gerrit.exceptions.NoSuchGroupException;
import com.google.gerrit.extensions.client.AuthType;
import com.google.gerrit.pgm.init.api.ConsoleUI;
import com.google.gerrit.pgm.init.api.InitFlags;
import com.google.gerrit.pgm.init.api.InitStep;
import com.google.gerrit.pgm.init.api.SequencesOnInit;
import com.google.gerrit.server.account.AccountSshKey;
import com.google.gerrit.server.account.AccountState;
import com.google.gerrit.server.account.externalids.ExternalId;
import com.google.gerrit.server.account.externalids.ExternalIdFactory;
import com.google.gerrit.server.index.account.AccountIndex;
import com.google.gerrit.server.index.account.AccountIndexCollection;
import com.google.gerrit.server.index.group.GroupIndex;
import com.google.gerrit.server.index.group.GroupIndexCollection;
import com.google.gerrit.server.util.time.TimeUtil;
import com.google.inject.Inject;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import org.apache.commons.validator.routines.EmailValidator;

public class InitAdminUser implements InitStep {
  private final InitFlags flags;
  private final ConsoleUI ui;
  private final AccountsOnInit accounts;
  private final VersionedAuthorizedKeysOnInit.Factory authorizedKeysFactory;
  private final ExternalIdsOnInit externalIds;
  private final SequencesOnInit sequencesOnInit;
  private final GroupsOnInit groupsOnInit;
  private final ExternalIdFactory externalIdFactory;
  private AccountIndexCollection accountIndexCollection;
  private GroupIndexCollection groupIndexCollection;

  @Inject
  InitAdminUser(
      InitFlags flags,
      ConsoleUI ui,
      AccountsOnInit accounts,
      VersionedAuthorizedKeysOnInit.Factory authorizedKeysFactory,
      ExternalIdsOnInit externalIds,
      SequencesOnInit sequencesOnInit,
      GroupsOnInit groupsOnInit,
      ExternalIdFactory externalIdFactory) {
    this.flags = flags;
    this.ui = ui;
    this.accounts = accounts;
    this.authorizedKeysFactory = authorizedKeysFactory;
    this.externalIds = externalIds;
    this.sequencesOnInit = sequencesOnInit;
    this.groupsOnInit = groupsOnInit;
    this.externalIdFactory = externalIdFactory;
  }

  @Override
  public void run() {}

  @Inject
  void set(AccountIndexCollection accountIndexCollection) {
    this.accountIndexCollection = accountIndexCollection;
  }

  @Inject
  void set(GroupIndexCollection groupIndexCollection) {
    this.groupIndexCollection = groupIndexCollection;
  }

  @Override
  public void postRun() throws Exception {
    if (!accounts.hasAnyAccount()) {
      welcome();
    }
    AuthType authType = flags.cfg.getEnum(AuthType.values(), "auth", null, "type", null);
    if (authType != AuthType.DEVELOPMENT_BECOME_ANY_ACCOUNT) {
      return;
    }

    if (!accounts.hasAnyAccount()) {
      ui.header("Gerrit Administrator");
      if (ui.yesno(true, "Create administrator user")) {
        Account.Id id = Account.id(sequencesOnInit.nextAccountId());
        String username = ui.readString("admin", "username");
        String name = ui.readString("Administrator", "name");
        String httpPassword = ui.readString("secret", "HTTP password");
        AccountSshKey sshKey = readSshKey(id);
        String email = readEmail(sshKey);

        List<ExternalId> extIds = new ArrayList<>(2);
        extIds.add(externalIdFactory.createUsername(username, id, httpPassword));

        if (email != null) {
          extIds.add(externalIdFactory.createEmail(id, email));
        }
        externalIds.insert("Add external IDs for initial admin user", extIds);

        Account persistedAccount =
            accounts.insert(
                Account.builder(id, TimeUtil.now()).setFullName(name).setPreferredEmail(email));
        // Only two groups should exist at this point in time and hence iterating over all of them
        // is cheap.
        Optional<GroupReference> adminGroupReference =
            groupsOnInit
                .getAllGroupReferences()
                .filter(group -> group.getName().equals("Administrators"))
                .findAny();
        if (!adminGroupReference.isPresent()) {
          throw new NoSuchGroupException("Administrators");
        }
        GroupReference adminGroup = adminGroupReference.get();
        groupsOnInit.addGroupMember(adminGroup.getUUID(), persistedAccount);

        if (sshKey != null) {
          VersionedAuthorizedKeysOnInit authorizedKeys = authorizedKeysFactory.create(id).load();
          authorizedKeys.addKey(sshKey.sshPublicKey());
          authorizedKeys.save("Add SSH key for initial admin user\n");
        }

        AccountState as = AccountState.forAccount(persistedAccount, extIds);
        for (AccountIndex accountIndex : accountIndexCollection.getWriteIndexes()) {
          accountIndex.replace(as);
        }

        InternalGroup adminInternalGroup = groupsOnInit.getExistingGroup(adminGroup);
        for (GroupIndex groupIndex : groupIndexCollection.getWriteIndexes()) {
          groupIndex.replace(adminInternalGroup);
        }
      }
    }
  }

  private void welcome() {
    ui.message(
        "============================================================================\n"
            + "Welcome to the Gerrit community\n\n"
            + "Find more information on the homepage: https://www.gerritcodereview.com\n"
            + "Discuss Gerrit on the mailing list: https://groups.google.com/g/repo-discuss\n"
            + "============================================================================\n");
  }

  private String readEmail(AccountSshKey sshKey) {
    String defaultEmail = "admin@example.com";
    if (sshKey != null && sshKey.comment() != null) {
      String c = sshKey.comment().trim();
      if (EmailValidator.getInstance().isValid(c)) {
        defaultEmail = c;
      }
    }
    return readEmail(defaultEmail);
  }

  private String readEmail(String defaultEmail) {
    String email = ui.readString(defaultEmail, "email");
    if (email != null && !EmailValidator.getInstance().isValid(email)) {
      ui.message("error: invalid email address\n");
      return readEmail(defaultEmail);
    }
    return email;
  }

  @Nullable
  private AccountSshKey readSshKey(Account.Id id) throws IOException {
    String defaultPublicSshKeyFile = "";
    Path defaultPublicSshKeyPath = Path.of(System.getProperty("user.home"), ".ssh", "id_rsa.pub");
    if (Files.exists(defaultPublicSshKeyPath)) {
      defaultPublicSshKeyFile = defaultPublicSshKeyPath.toString();
    }
    String publicSshKeyFile = ui.readString(defaultPublicSshKeyFile, "public SSH key file");
    return !Strings.isNullOrEmpty(publicSshKeyFile) ? createSshKey(id, publicSshKeyFile) : null;
  }

  private AccountSshKey createSshKey(Account.Id id, String keyFile) throws IOException {
    Path p = Path.of(keyFile);
    if (!Files.exists(p)) {
      throw new IOException(String.format("Cannot add public SSH key: %s is not a file", keyFile));
    }
    String content = new String(Files.readAllBytes(p), UTF_8);
    return AccountSshKey.create(id, 1, content);
  }
}