// 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.extensions.api.projects;

import com.google.gerrit.extensions.client.ProjectState;
import com.google.gerrit.extensions.common.ProjectInfo;
import com.google.gerrit.extensions.restapi.NotImplementedException;
import com.google.gerrit.extensions.restapi.RestApiException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;

public interface Projects {
  /**
   * Look up a project by name.
   *
   * <p><strong>Note:</strong> This method eagerly reads the project. Methods that mutate the
   * project do not necessarily re-read the project. Therefore, calling a getter method on an
   * instance after calling a mutation method on that same instance is not guaranteed to reflect the
   * mutation. It is not recommended to store references to {@code ProjectApi} instances.
   *
   * @param name project name.
   * @return API for accessing the project.
   * @throws RestApiException if an error occurred.
   */
  ProjectApi name(String name) throws RestApiException;

  /**
   * Create a project using the default configuration.
   *
   * @param name project name.
   * @return API for accessing the newly-created project.
   * @throws RestApiException if an error occurred.
   */
  ProjectApi create(String name) throws RestApiException;

  /**
   * Create a project.
   *
   * @param in project creation input; name must be set.
   * @return API for accessing the newly-created project.
   * @throws RestApiException if an error occurred.
   */
  ProjectApi create(ProjectInput in) throws RestApiException;

  ListRequest list();

  /**
   * Query projects.
   *
   * <p>Example code: {@code query().withQuery("name:project").get()}
   *
   * @return API for setting parameters and getting result.
   */
  QueryRequest query();

  /**
   * Query projects.
   *
   * <p>Shortcut API for {@code query().withQuery(String)}.
   *
   * @see #query()
   */
  QueryRequest query(String query);

  abstract class ListRequest {
    public enum FilterType {
      CODE,
      PARENT_CANDIDATES,
      PERMISSIONS,
      ALL
    }

    private final List<String> branches = new ArrayList<>();
    private boolean description;
    private String prefix;
    private String substring;
    private String regex;
    private int limit;
    private int start;
    private boolean showTree;
    private boolean all;
    private FilterType type = FilterType.ALL;
    private ProjectState state = null;

    public List<ProjectInfo> get() throws RestApiException {
      Map<String, ProjectInfo> map = getAsMap();
      List<ProjectInfo> result = new ArrayList<>(map.size());
      for (Map.Entry<String, ProjectInfo> e : map.entrySet()) {
        // ListProjects "helpfully" nulls out names when converting to a map.
        e.getValue().name = e.getKey();
        result.add(e.getValue());
      }
      return Collections.unmodifiableList(result);
    }

    public abstract SortedMap<String, ProjectInfo> getAsMap() throws RestApiException;

    public ListRequest withDescription(boolean description) {
      this.description = description;
      return this;
    }

    public ListRequest withPrefix(String prefix) {
      this.prefix = prefix;
      return this;
    }

    public ListRequest withSubstring(String substring) {
      this.substring = substring;
      return this;
    }

    public ListRequest withRegex(String regex) {
      this.regex = regex;
      return this;
    }

    public ListRequest withLimit(int limit) {
      this.limit = limit;
      return this;
    }

    public ListRequest withStart(int start) {
      this.start = start;
      return this;
    }

    public ListRequest addShowBranch(String branch) {
      branches.add(branch);
      return this;
    }

    public ListRequest withTree(boolean show) {
      showTree = show;
      return this;
    }

    public ListRequest withType(FilterType type) {
      this.type = type != null ? type : FilterType.ALL;
      return this;
    }

    public ListRequest withAll(boolean all) {
      this.all = all;
      return this;
    }

    public ListRequest withState(ProjectState state) {
      this.state = state;
      return this;
    }

    public boolean getDescription() {
      return description;
    }

    public String getPrefix() {
      return prefix;
    }

    public String getSubstring() {
      return substring;
    }

    public String getRegex() {
      return regex;
    }

    public int getLimit() {
      return limit;
    }

    public int getStart() {
      return start;
    }

    public List<String> getBranches() {
      return Collections.unmodifiableList(branches);
    }

    public boolean getShowTree() {
      return showTree;
    }

    public FilterType getFilterType() {
      return type;
    }

    public boolean isAll() {
      return all;
    }

    public ProjectState getState() {
      return state;
    }
  }

  /**
   * API for setting parameters and getting result. Used for {@code query()}.
   *
   * @see #query()
   */
  abstract class QueryRequest {
    private String query;
    private int limit;
    private int start;

    /** Execute query and returns the matched projects as list. */
    public abstract List<ProjectInfo> get() throws RestApiException;

    /**
     * Set query.
     *
     * @param query needs to be in human-readable form.
     */
    public QueryRequest withQuery(String query) {
      this.query = query;
      return this;
    }

    /**
     * Set limit for returned list of projects. Optional; server-default is used when not provided.
     */
    public QueryRequest withLimit(int limit) {
      this.limit = limit;
      return this;
    }

    /** Set number of projects to skip. Optional; no projects are skipped when not provided. */
    public QueryRequest withStart(int start) {
      this.start = start;
      return this;
    }

    public String getQuery() {
      return query;
    }

    public int getLimit() {
      return limit;
    }

    public int getStart() {
      return start;
    }
  }

  /**
   * A default implementation which allows source compatibility when adding new methods to the
   * interface.
   */
  class NotImplemented implements Projects {
    @Override
    public ProjectApi name(String name) throws RestApiException {
      throw new NotImplementedException();
    }

    @Override
    public ProjectApi create(ProjectInput in) throws RestApiException {
      throw new NotImplementedException();
    }

    @Override
    public ProjectApi create(String name) throws RestApiException {
      throw new NotImplementedException();
    }

    @Override
    public ListRequest list() {
      throw new NotImplementedException();
    }

    @Override
    public QueryRequest query() {
      throw new NotImplementedException();
    }

    @Override
    public QueryRequest query(String query) {
      throw new NotImplementedException();
    }
  }
}