docbrown/app/controllers/search_controller.rb

class SearchController < ApplicationController
  before_action :authenticate_user!, only: %i[tags chat_channels reactions usernames]
  before_action :format_integer_params
  before_action :sanitize_params, only: %i[listings reactions feed_content]

  CHAT_CHANNEL_PARAMS = %i[
    channel_status
    channel_type
    page
    per_page
    status
    user_id
  ].freeze

  LISTINGS_PARAMS = [
    :category,
    :listing_search,
    :page,
    :per_page,
    :tag_boolean_mode,
    {
      tags: []
    },
  ].freeze

  REACTION_PARAMS = [
    :page,
    :per_page,
    :category,
    :search_fields,
    :tag_boolean_mode,
    {
      tag_names: [],
      status: []
    },
  ].freeze

  USER_PARAMS = %i[
    search_fields
    page
    per_page
  ].freeze

  FEED_PARAMS = [
    :approved,
    :class_name,
    :id,
    :organization_id,
    :page,
    :per_page,
    :search_fields,
    :sort_by,
    :sort_direction,
    :user_id,
    {
      tag_names: [],
      published_at: [:gte]
    },
  ].freeze

  def tags
    result = if FeatureFlag.enabled?(:search_2_tags)
               Search::Postgres::Tag.search_documents(params[:name])
             else
               Search::Tag.search_documents("name:#{params[:name]}* AND supported:true")
             end

    render json: { result: result }
  rescue Search::Errors::Transport::BadRequest
    render json: { result: [] }
  end

  def chat_channels
    user_ids =
      if chat_channel_params[:user_id].present?
        [current_user.id, Settings::Mascot.mascot_user_id, chat_channel_params[:user_id]].reject(&:blank?)
      else
        [current_user.id]
      end

    result = Search::Postgres::ChatChannelMembership.search_documents(
      user_ids: user_ids,
      page: chat_channel_params[:page],
      per_page: chat_channel_params[:per_page],
    )

    render json: { result: result }
  end

  def listings
    result =
      if FeatureFlag.enabled?(:search_2_listings)
        Search::Postgres::Listing.search_documents(
          category: listing_params[:category],
          page: listing_params[:page],
          per_page: listing_params[:per_page],
          term: listing_params[:listing_search],
        )
      else
        Search::Listing.search_documents(params: listing_params.to_h)
      end

    render json: { result: result }
  end

  def users
    render json: { result: user_search }
  end

  def usernames
    result = if FeatureFlag.enabled?(:search_2_usernames)
               Search::Postgres::Username.search_documents(params[:username])
             else
               Search::User.search_usernames(params[:username])
             end

    render json: { result: result }
  rescue Search::Errors::Transport::BadRequest
    render json: { result: [] }
  end

  # TODO: [@rhymes] the homepage feed uses `feed_content_search` as an index,
  # we should eventually move it to a JSON result
  # in ArticlesController#Homepage or HomepageController#show
  # rubocop:disable Metric/PerceivedComplexity
  def feed_content
    class_name = feed_params[:class_name].to_s.inquiry

    result =
      if class_name.blank?
        # If we are in the main feed and not filtering by type return
        # all articles, podcast episodes, and users
        feed_content_search.concat(user_search)
      elsif class_name.Article? && feed_params[:search_fields].blank?
        # homepage
        if FeatureFlag.enabled?(:search_2_homepage)
          # NOTE: published_at is sent from the frontend in the following ES-friendly format:
          # => {"published_at"=>{"gte"=>"2021-04-06T14:53:23Z"}}
          published_at_gte = params.dig(:published_at, :gte)
          published_at_gte = Time.zone.parse(published_at_gte) if published_at_gte
          published_at = published_at_gte ? published_at_gte.. : nil

          Homepage::FetchArticles.call(
            approved: params[:approved],
            published_at: published_at,
            sort_by: params[:sort_by],
            sort_direction: params[:sort_direction],
            page: params[:page],
            per_page: params[:per_page],
          )
        else
          feed_content_search
        end
      elsif class_name.Comment? && FeatureFlag.enabled?(:search_2_comments)
        Search::Postgres::Comment.search_documents(
          page: feed_params[:page],
          per_page: feed_params[:per_page],
          sort_by: feed_params[:sort_by],
          sort_direction: feed_params[:sort_direction],
          term: feed_params[:search_fields],
        )
      elsif class_name.User?
        if FeatureFlag.enabled?(:search_2_users)
          Search::Postgres::User.search_documents(
            term: feed_params[:search_fields],
            page: feed_params[:page],
            per_page: feed_params[:per_page],
            sort_by: feed_params[:sort_by] == "published_at" ? :created_at : nil,
            sort_direction: feed_params[:sort_direction],
          )
        else
          user_search
        end
      else # search page
        feed_content_search
      end

    render json: { result: result }
  end
  # rubocop:enable Metric/PerceivedComplexity

  def reactions
    if FeatureFlag.enabled?(:search_2_reading_list)
      # [@rhymes] we're recyling the existing params as we want to change the frontend as
      # little as possible, we might simplify in the future
      result = Search::Postgres::ReadingList.search_documents(
        current_user,
        page: reaction_params[:page],
        per_page: reaction_params[:per_page],
        statuses: reaction_params[:status],
        tags: reaction_params[:tag_names],
        term: reaction_params[:search_fields],
      )

      render json: { result: result[:items], total: result[:total] }
    else
      result = Search::ReadingList.search_documents(
        params: reaction_params.to_h, user: current_user,
      )

      render json: { result: result["reactions"], total: result["total"] }
    end
  end

  private

  def feed_content_search
    Search::FeedContent.search_documents(params: feed_params.to_h)
  end

  def user_search
    Search::User.search_documents(params: user_params.to_h)
  end

  def chat_channel_params
    params.permit(CHAT_CHANNEL_PARAMS)
  end

  def listing_params
    params.permit(LISTINGS_PARAMS)
  end

  def user_params
    params.permit(USER_PARAMS)
  end

  def feed_params
    params.permit(FEED_PARAMS)
  end

  def reaction_params
    params.permit(REACTION_PARAMS)
  end

  def format_integer_params
    params[:page] = params[:page].to_i if params[:page].present?
    params[:per_page] = params[:per_page].to_i if params[:per_page].present?
  end

  # Some Elasticsearches/QueryBuilders treat values such as empty Strings and
  # nil differently. This is a helper method to remove any params that are
  # blank before passing it to Elasticsearch.
  def sanitize_params
    params.delete_if { |_k, v| v.blank? }
  end
end