// Copyright (C) 2013 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.restapi.group;

import static com.google.gerrit.extensions.client.ListGroupsOption.INCLUDES;
import static com.google.gerrit.extensions.client.ListGroupsOption.MEMBERS;

import com.google.common.base.Strings;
import com.google.common.base.Suppliers;
import com.google.gerrit.common.data.GroupDescription;
import com.google.gerrit.entities.AccountGroup;
import com.google.gerrit.extensions.client.ListGroupsOption;
import com.google.gerrit.extensions.common.GroupInfo;
import com.google.gerrit.extensions.common.GroupOptionsInfo;
import com.google.gerrit.extensions.restapi.Url;
import com.google.gerrit.server.account.GroupBackend;
import com.google.gerrit.server.account.GroupControl;
import com.google.gerrit.server.group.GroupResource;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.util.Collection;
import java.util.EnumSet;
import java.util.function.Supplier;

public class GroupJson {
  public static GroupOptionsInfo createOptions(GroupDescription.Basic group) {
    GroupOptionsInfo options = new GroupOptionsInfo();
    if (group instanceof GroupDescription.Internal
        && ((GroupDescription.Internal) group).isVisibleToAll()) {
      options.visibleToAll = true;
    }
    return options;
  }

  private final GroupBackend groupBackend;
  private final GroupControl.Factory groupControlFactory;
  private final Provider<ListMembers> listMembers;
  private final Provider<ListSubgroups> listSubgroups;
  private EnumSet<ListGroupsOption> options;

  @Inject
  GroupJson(
      GroupBackend groupBackend,
      GroupControl.Factory groupControlFactory,
      Provider<ListMembers> listMembers,
      Provider<ListSubgroups> listSubgroups) {
    this.groupBackend = groupBackend;
    this.groupControlFactory = groupControlFactory;
    this.listMembers = listMembers;
    this.listSubgroups = listSubgroups;

    options = EnumSet.noneOf(ListGroupsOption.class);
  }

  public GroupJson addOption(ListGroupsOption o) {
    options.add(o);
    return this;
  }

  public GroupJson addOptions(Collection<ListGroupsOption> o) {
    options.addAll(o);
    return this;
  }

  public GroupInfo format(GroupResource rsrc) throws PermissionBackendException {
    return createGroupInfo(rsrc.getGroup(), rsrc::getControl);
  }

  public GroupInfo format(GroupDescription.Basic group) throws PermissionBackendException {
    return createGroupInfo(group, Suppliers.memoize(() -> groupControlFactory.controlFor(group)));
  }

  private GroupInfo createGroupInfo(
      GroupDescription.Basic group, Supplier<GroupControl> groupControlSupplier)
      throws PermissionBackendException {
    GroupInfo info = createBasicGroupInfo(group);

    if (group instanceof GroupDescription.Internal) {
      addInternalDetails(info, (GroupDescription.Internal) group, groupControlSupplier);
    }

    return info;
  }

  private static GroupInfo createBasicGroupInfo(GroupDescription.Basic group) {
    GroupInfo info = new GroupInfo();
    info.id = Url.encode(group.getGroupUUID().get());
    info.name = Strings.emptyToNull(group.getName());
    info.url = Strings.emptyToNull(group.getUrl());
    info.options = createOptions(group);
    return info;
  }

  private void addInternalDetails(
      GroupInfo info,
      GroupDescription.Internal internalGroup,
      Supplier<GroupControl> groupControlSupplier)
      throws PermissionBackendException {
    info.description = Strings.emptyToNull(internalGroup.getDescription());
    info.groupId = internalGroup.getId().get();

    AccountGroup.UUID ownerGroupUUID = internalGroup.getOwnerGroupUUID();
    if (ownerGroupUUID != null) {
      info.ownerId = Url.encode(ownerGroupUUID.get());
      GroupDescription.Basic o = groupBackend.get(ownerGroupUUID);
      if (o != null) {
        info.owner = o.getName();
      }
    }

    info.createdOn = internalGroup.getCreatedOn();

    if (options.contains(MEMBERS)) {
      info.members = listMembers.get().getDirectMembers(internalGroup, groupControlSupplier.get());
    }

    if (options.contains(INCLUDES)) {
      info.includes =
          listSubgroups.get().getDirectSubgroups(internalGroup, groupControlSupplier.get());
    }
  }
}