Websites/app/logical/pool_index.rb

module PoolIndex
  module_function

  def index_name
    "pools_#{Rails.env}"
  end

  def index_config
    {
      settings: {
        index: {
          number_of_shards:   1,
          number_of_replicas: 0,
          max_result_window:  100_000,
        },
      },
      mappings: {
        dynamic:    false,
        properties: {
          id:          { type: "integer" },
          tags:        { type: "keyword" },
          name:        { type: "text" },
          name_kw:     { type: "keyword" },
          created_at:  { type: "date" },
          updated_at:  { type: "date" },
          creator_id:  { type: "integer" },
          description: { type: "text" },
          is_active:   { type: "boolean" },
          category:    { type: "keyword" },
          post_ids:    { type: "integer" },
          post_count:  { type: "integer" },
        },
      },
    }
  end

  def as_indexed_json(pool)
    tags = pool.tag_string.split
    {
      id:          pool.id,
      tags:        tags,
      name:        pool.name,
      name_kw:     pool.name,
      created_at:  pool.created_at,
      updated_at:  pool.updated_at,
      creator_id:  pool.creator_id,
      description: pool.description,
      is_active:   pool.is_active,
      category:    pool.category,
      post_ids:    pool.post_ids,
      post_count:  pool.post_ids.size,
    }
  end

  def import!
    create_index!(delete_existing: true)
    E621::Pool.find_in_batches(batch_size: 1000) do |batch|
      batch.map! do |pool|
        {
          index: {
            _id:  pool.id,
            data: as_indexed_json(pool),
          },
        }
      end

      client.bulk(body: batch, index: index_name)
    end
  end

  def create_index!(delete_existing: false)
    exists = index_exist?
    delete_index! if exists && delete_existing
    client.indices.create(index: index_name, body: index_config)
  end

  def delete_index!
    client.indices.delete(index: index_name, ignore: 404)
  end

  def index_exist?
    client.indices.exists(index: index_name)
  end

  def refresh_index!
    client.indices.refresh(index: index_name)
  end

  def update_document(pool)
    client.index(index: index_name, id: pool.id, body: as_indexed_json(pool))
  end

  def delete_document(id)
    client.delete(index: index_name, id: id)
  end

  def client
    @client ||= OpenSearch::Client.new(host: Websites.config.opensearch_host, request_timeout: 120)
  end

  def search(page, limit, must: [], must_not: [], should: [], order: nil)
    page ||= 1
    limit ||= 100
    query = {
      bool: {
        must:     must,
        must_not: must_not,
        should:   should,
      },
    }
    query[:bool][:minimum_should_match] = 1 if should.any?
    query[:bool][:must].push({ match_all: {} }) if query[:bool][:must].empty?
    from = (page - 1) * limit
    body = {
      from:    from,
      size:    limit,
      query:   query,
      sort:    order,
      _source: false,
      timeout: "3000ms",
    }

    results = client.search(index: index_name, body: body)["hits"]["hits"].map { |hit| hit["_id"].to_i }
    count = client.count(index: index_name, body: { query: query })["count"]
    { results: results, count: count }
  end
end