// 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.account;

import static com.google.gerrit.server.config.ConfigUtil.loadSection;

import com.google.gerrit.extensions.client.DiffPreferencesInfo;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.RestReadView;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.config.AllUsersName;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.git.UserConfigSections;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;

import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.errors.RepositoryNotFoundException;
import org.eclipse.jgit.lib.Repository;

import java.io.IOException;

@Singleton
public class GetDiffPreferences implements RestReadView<AccountResource> {
  private final Provider<CurrentUser> self;
  private final Provider<AllUsersName> allUsersName;
  private final GitRepositoryManager gitMgr;

  @Inject
  GetDiffPreferences(Provider<CurrentUser> self,
      Provider<AllUsersName> allUsersName,
      GitRepositoryManager gitMgr) {
    this.self = self;
    this.allUsersName = allUsersName;
    this.gitMgr = gitMgr;
  }

  @Override
  public DiffPreferencesInfo apply(AccountResource rsrc)
      throws AuthException, ConfigInvalidException, IOException {
    if (self.get() != rsrc.getUser()
        && !self.get().getCapabilities().canAdministrateServer()) {
      throw new AuthException("restricted to administrator");
    }

    Account.Id id = rsrc.getUser().getAccountId();
    return readFromGit(id, gitMgr, allUsersName.get(), null);
  }

  static DiffPreferencesInfo readFromGit(Account.Id id,
      GitRepositoryManager gitMgr, AllUsersName allUsersName,
      DiffPreferencesInfo in)
      throws IOException, ConfigInvalidException, RepositoryNotFoundException {
    try (Repository git = gitMgr.openRepository(allUsersName)) {
      VersionedAccountPreferences p =
          VersionedAccountPreferences.forUser(id);
      p.load(git);
      DiffPreferencesInfo prefs = new DiffPreferencesInfo();
      loadSection(p.getConfig(), UserConfigSections.DIFF, null, prefs,
          DiffPreferencesInfo.defaults(), in);
      return prefs;
    }
  }
}