// Copyright (C) 2020 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.plugins.codeowners.api;

import static com.google.gerrit.server.api.ApiUtil.asRestApiException;

import com.google.gerrit.extensions.restapi.BadRequestException;
import com.google.gerrit.extensions.restapi.IdString;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.plugins.codeowners.restapi.CodeOwnersInChangeCollection;
import com.google.gerrit.plugins.codeowners.restapi.GetCodeOwnersForPathInChange;
import com.google.gerrit.server.change.RevisionResource;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.assistedinject.Assisted;
import java.nio.file.Path;
import java.util.List;

/** Implementation of the {@link CodeOwners} API for a revision in a change. */
public class CodeOwnersInChangeImpl implements CodeOwners {
  interface Factory {
    CodeOwnersInChangeImpl create(RevisionResource revisionResource);
  }

  private final CodeOwnersInChangeCollection codeOwnersInChangeCollection;
  private final Provider<GetCodeOwnersForPathInChange> getCodeOwnersProvider;
  private final RevisionResource revisionResource;

  @Inject
  public CodeOwnersInChangeImpl(
      CodeOwnersInChangeCollection codeOwnersInChangeCollection,
      Provider<GetCodeOwnersForPathInChange> getCodeOwnersProvider,
      @Assisted RevisionResource revisionResource) {
    this.codeOwnersInChangeCollection = codeOwnersInChangeCollection;
    this.getCodeOwnersProvider = getCodeOwnersProvider;
    this.revisionResource = revisionResource;
  }

  @Override
  public QueryRequest query() {
    return new QueryRequest() {
      @Override
      public List<CodeOwnerInfo> get(Path path) throws RestApiException {
        try {
          if (getRevision().isPresent()) {
            throw new BadRequestException("specifying revision is not supported");
          }

          GetCodeOwnersForPathInChange getCodeOwners = getCodeOwnersProvider.get();
          getOptions().forEach(getCodeOwners::addOption);
          getLimit().ifPresent(getCodeOwners::setLimit);
          CodeOwnersInChangeCollection.PathResource pathInChangeResource =
              codeOwnersInChangeCollection.parse(
                  revisionResource, IdString.fromDecoded(path.toString()));
          return getCodeOwners.apply(pathInChangeResource).value();
        } catch (Exception e) {
          throw asRestApiException("Cannot get code owners", e);
        }
      }
    };
  }
}