// 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.api.projects;

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

import com.google.gerrit.entities.RefNames;
import com.google.gerrit.extensions.api.changes.ChangeApi.SuggestedReviewersRequest;
import com.google.gerrit.extensions.api.projects.BranchApi;
import com.google.gerrit.extensions.api.projects.BranchInfo;
import com.google.gerrit.extensions.api.projects.BranchInput;
import com.google.gerrit.extensions.api.projects.ReflogEntryInfo;
import com.google.gerrit.extensions.common.Input;
import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
import com.google.gerrit.extensions.restapi.BinaryResult;
import com.google.gerrit.extensions.restapi.IdString;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.gerrit.server.project.BranchResource;
import com.google.gerrit.server.project.FileResource;
import com.google.gerrit.server.project.ProjectResource;
import com.google.gerrit.server.restapi.project.BranchesCollection;
import com.google.gerrit.server.restapi.project.CreateBranch;
import com.google.gerrit.server.restapi.project.DeleteBranch;
import com.google.gerrit.server.restapi.project.FilesCollection;
import com.google.gerrit.server.restapi.project.GetBranch;
import com.google.gerrit.server.restapi.project.GetContent;
import com.google.gerrit.server.restapi.project.GetReflog;
import com.google.gerrit.server.restapi.project.SuggestBranchReviewers;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;
import java.io.IOException;
import java.util.List;

public class BranchApiImpl implements BranchApi {
  interface Factory {
    BranchApiImpl create(ProjectResource project, String ref);
  }

  private final BranchesCollection branches;
  private final CreateBranch createBranch;
  private final DeleteBranch deleteBranch;
  private final FilesCollection filesCollection;
  private final GetBranch getBranch;
  private final GetContent getContent;
  private final GetReflog getReflog;
  private final String ref;
  private final ProjectResource project;

  private final SuggestBranchReviewers suggestReviewers;

  @Inject
  BranchApiImpl(
      BranchesCollection branches,
      CreateBranch createBranch,
      DeleteBranch deleteBranch,
      FilesCollection filesCollection,
      GetBranch getBranch,
      GetContent getContent,
      GetReflog getReflog,
      SuggestBranchReviewers suggestReviewers,
      @Assisted ProjectResource project,
      @Assisted String ref) {
    this.branches = branches;
    this.createBranch = createBranch;
    this.deleteBranch = deleteBranch;
    this.filesCollection = filesCollection;
    this.getBranch = getBranch;
    this.getContent = getContent;
    this.getReflog = getReflog;
    this.project = project;
    this.suggestReviewers = suggestReviewers;
    this.ref = ref;
  }

  @Override
  public BranchApi create(BranchInput input) throws RestApiException {
    try {
      createBranch.apply(project, IdString.fromDecoded(ref), input);
      return this;
    } catch (Exception e) {
      throw asRestApiException("Cannot create branch", e);
    }
  }

  @Override
  public BranchInfo get() throws RestApiException {
    try {
      return getBranch.apply(resource()).value();
    } catch (Exception e) {
      throw asRestApiException("Cannot read branch", e);
    }
  }

  @Override
  public void delete() throws RestApiException {
    try {
      deleteBranch.apply(resource(), new Input());
    } catch (Exception e) {
      throw asRestApiException("Cannot delete branch", e);
    }
  }

  @Override
  public SuggestedReviewersRequest suggestReviewers() throws RestApiException {
    return new SuggestedReviewersRequest() {
      @Override
      public List<SuggestedReviewerInfo> get() throws RestApiException {
        return BranchApiImpl.this.suggestReviewers(this);
      }
    };
  }

  private List<SuggestedReviewerInfo> suggestReviewers(SuggestedReviewersRequest r)
      throws RestApiException {
    try {
      suggestReviewers.setQuery(r.getQuery());
      suggestReviewers.setLimit(r.getLimit());
      suggestReviewers.setExcludeGroups(r.getExcludeGroups());
      suggestReviewers.setReviewerState(r.getReviewerState());
      return suggestReviewers.apply(resource()).value();
    } catch (Exception e) {
      throw asRestApiException("Cannot retrieve suggested reviewers", e);
    }
  }

  @Override
  public BinaryResult file(String path) throws RestApiException {
    try {
      FileResource resource = filesCollection.parse(resource(), IdString.fromDecoded(path));
      return getContent.apply(resource).value();
    } catch (Exception e) {
      throw asRestApiException("Cannot retrieve file", e);
    }
  }

  @Override
  public List<ReflogEntryInfo> reflog() throws RestApiException {
    try {
      return getReflog.apply(resource()).value();
    } catch (Exception e) {
      throw asRestApiException("Cannot retrieve reflog", e);
    }
  }

  private BranchResource resource()
      throws RestApiException, IOException, PermissionBackendException {
    String refName = ref;
    if (RefNames.isRefsUsersSelf(ref, project.getProjectState().isAllUsers())) {
      refName = RefNames.refsUsers(project.getUser().getAccountId());
    }
    return branches.parse(project, IdString.fromDecoded(refName));
  }
}