// 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.group;

import com.google.common.base.Strings;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.DefaultInput;
import com.google.gerrit.extensions.restapi.MethodNotAllowedException;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestModifyView;
import com.google.gerrit.reviewdb.client.AccountGroup;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.account.GroupCache;
import com.google.gerrit.server.group.PutDescription.Input;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;

import java.util.Collections;

@Singleton
public class PutDescription implements RestModifyView<GroupResource, Input> {
  public static class Input {
    @DefaultInput
    public String description;
  }

  private final GroupCache groupCache;
  private final Provider<ReviewDb> db;

  @Inject
  PutDescription(GroupCache groupCache, Provider<ReviewDb> db) {
    this.groupCache = groupCache;
    this.db = db;
  }

  @Override
  public Response<String> apply(GroupResource resource, Input input)
      throws AuthException, MethodNotAllowedException,
      ResourceNotFoundException, OrmException {
    if (input == null) {
      input = new Input(); // Delete would set description to null.
    }

    if (resource.toAccountGroup() == null) {
      throw new MethodNotAllowedException();
    } else if (!resource.getControl().isOwner()) {
      throw new AuthException("Not group owner");
    }

    AccountGroup group = db.get().accountGroups().get(
        resource.toAccountGroup().getId());
    if (group == null) {
      throw new ResourceNotFoundException();
    }

    group.setDescription(Strings.emptyToNull(input.description));
    db.get().accountGroups().update(Collections.singleton(group));
    groupCache.evict(group);

    return Strings.isNullOrEmpty(input.description)
        ? Response.<String>none()
        : Response.ok(input.description);
  }
}