// Copyright (C) 2018 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.elasticsearch;

import com.google.gson.JsonObject;

public class ElasticQueryAdapter {
  static final String POST_V5_TYPE = "_doc";

  private final boolean ignoreUnmapped;
  private final boolean usePostV5Type;

  private final String searchFilteringName;
  private final String indicesExistParam;
  private final String exactFieldType;
  private final String stringFieldType;
  private final String indexProperty;
  private final String rawFieldsKey;
  private final String versionDiscoveryUrl;

  ElasticQueryAdapter(ElasticVersion version) {
    this.ignoreUnmapped = version == ElasticVersion.V2_4;
    this.usePostV5Type = isV6(version);
    this.versionDiscoveryUrl = isV6(version) ? "%s*" : "%s*/_aliases";

    switch (version) {
      case V5_6:
      case V6_2:
      case V6_3:
        this.searchFilteringName = "_source";
        this.indicesExistParam = "?allow_no_indices=false";
        this.exactFieldType = "keyword";
        this.stringFieldType = "text";
        this.indexProperty = "true";
        this.rawFieldsKey = "_source";
        break;
      case V2_4:
      default:
        this.searchFilteringName = "fields";
        this.indicesExistParam = "";
        this.exactFieldType = "string";
        this.stringFieldType = "string";
        this.indexProperty = "not_analyzed";
        this.rawFieldsKey = "fields";
        break;
    }
  }

  private boolean isV6(ElasticVersion version) {
    return version == ElasticVersion.V6_2 || version == ElasticVersion.V6_3;
  }

  void setIgnoreUnmapped(JsonObject properties) {
    if (ignoreUnmapped) {
      properties.addProperty("ignore_unmapped", true);
    }
  }

  public void setType(JsonObject properties, String type) {
    if (!usePostV5Type) {
      properties.addProperty("_type", type);
    }
  }

  public String searchFilteringName() {
    return searchFilteringName;
  }

  String indicesExistParam() {
    return indicesExistParam;
  }

  String exactFieldType() {
    return exactFieldType;
  }

  String stringFieldType() {
    return stringFieldType;
  }

  String indexProperty() {
    return indexProperty;
  }

  String rawFieldsKey() {
    return rawFieldsKey;
  }

  boolean usePostV5Type() {
    return usePostV5Type;
  }

  String getType(String preV6Type) {
    return usePostV5Type() ? POST_V5_TYPE : preV6Type;
  }

  String getVersionDiscoveryUrl(String name) {
    return String.format(versionDiscoveryUrl, name);
  }
}