// Copyright (C) 2018 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.server.group.testing;

import static com.google.common.base.Preconditions.checkState;
import static java.util.Objects.requireNonNull;

import com.google.common.collect.ImmutableList;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.entities.Account;
import com.google.gerrit.entities.AccountGroup;
import com.google.gerrit.entities.GroupDescription;
import com.google.gerrit.entities.GroupReference;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.account.GroupBackend;
import com.google.gerrit.server.account.GroupMembership;
import com.google.gerrit.server.project.ProjectState;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

/** Implementation of GroupBackend for tests. */
public class TestGroupBackend implements GroupBackend {
  public static final String PREFIX = "testbackend:";

  private final Map<AccountGroup.UUID, GroupDescription.Basic> groups = new HashMap<>();
  private final Map<Account.Id, GroupMembership> memberships = new HashMap<>();

  /**
   * Create a group by name.
   *
   * @param name the group name, optionally prefixed by "testbackend:".
   * @return the created group
   */
  public GroupDescription.Basic create(String name) {
    requireNonNull(name);
    return create(AccountGroup.uuid(name.startsWith(PREFIX) ? name : PREFIX + name));
  }

  /**
   * Create a group by UUID.
   *
   * @param uuid the group UUID to add.
   * @return the created group
   */
  public GroupDescription.Basic create(AccountGroup.UUID uuid) {
    checkState(uuid.get().startsWith(PREFIX), "test group UUID must have prefix '" + PREFIX + "'");
    if (groups.containsKey(uuid)) {
      return groups.get(uuid);
    }
    GroupDescription.Basic group =
        new GroupDescription.Basic() {
          @Override
          public AccountGroup.UUID getGroupUUID() {
            return uuid;
          }

          @Override
          public String getName() {
            return uuid.get().substring(PREFIX.length());
          }

          @Override
          public String getEmailAddress() {
            return null;
          }

          @Override
          public String getUrl() {
            return null;
          }
        };
    groups.put(uuid, group);
    return group;
  }

  /**
   * Remove a group. No-op if the group does not exist.
   *
   * @param uuid the group.
   */
  public void remove(AccountGroup.UUID uuid) {
    groups.remove(uuid);
  }

  /**
   * Makes this backend return the specified {@link GroupMembership} when being asked for the
   * specified {@link com.google.gerrit.entities.Account.Id}.
   */
  public void setMembershipsOf(Account.Id user, GroupMembership membership) {
    memberships.put(user, membership);
  }

  @Override
  public boolean handles(AccountGroup.UUID uuid) {
    if (uuid != null) {
      String id = uuid.get();
      return id != null && id.startsWith(PREFIX);
    }
    return false;
  }

  @Nullable
  @Override
  public GroupDescription.Basic get(AccountGroup.UUID uuid) {
    return uuid == null ? null : groups.get(uuid);
  }

  @Override
  public Collection<GroupReference> suggest(String name, ProjectState project) {
    AccountGroup.UUID uuid = AccountGroup.uuid(name);
    if (handles(uuid)) {
      GroupDescription.Basic g = get(uuid);
      if (g != null) {
        return ImmutableList.of(GroupReference.forGroup(g));
      }
    }
    return ImmutableList.of();
  }

  @Override
  public GroupMembership membershipsOf(CurrentUser user) {
    if (!user.isIdentifiedUser()) {
      return GroupMembership.EMPTY;
    }
    return memberships.getOrDefault(user.getAccountId(), GroupMembership.EMPTY);
  }

  @Override
  public boolean isVisibleToAll(AccountGroup.UUID uuid) {
    return false;
  }
}