# frozen_string_literal: true

module Decidim
  module ParticipatoryProcesses
    # A presenter to render statistics in the homepage.
    class ParticipatoryProcessStatsPresenter < Rectify::Presenter
      attribute :participatory_process, Decidim::ParticipatoryProcess
      include Decidim::IconHelper

      # Public: returns a collection of stats (Hash) for the Process Home.
      def collection
        highlighted_stats = process_participants_stats
        highlighted_stats = highlighted_stats.concat(process_followers_stats(priority: StatsRegistry::HIGH_PRIORITY))
        highlighted_stats = highlighted_stats.concat(component_stats(priority: StatsRegistry::HIGH_PRIORITY))
        highlighted_stats = highlighted_stats.concat(component_stats(priority: StatsRegistry::MEDIUM_PRIORITY))
        highlighted_stats = highlighted_stats.reject(&:empty?)
        highlighted_stats = highlighted_stats.reject { |_stat_manifest, _stat_title, stat_number| stat_number.zero? }
        grouped_highlighted_stats = highlighted_stats.group_by(&:first)

        statistics = []
        grouped_highlighted_stats.each do |_manifest_name, stats|
          stats.each_with_index.each do |stat, _index|
            stat.each_with_index.map do |_item, subindex|
              next unless (subindex % 3).zero?
              next if stat[subindex + 2].zero?

              statistics << { stat_title: stat[subindex + 1], stat_number: stat[subindex + 2] }
            end
          end
        end
        statistics
      end

      private

      def process_participants_stats
        Decidim.stats.only([:participants_count]).with_context(participatory_process)
               .map { |stat_title, stat_number| [participatory_process.manifest.name, stat_title, stat_number] }
      end

      def component_stats(conditions)
        Decidim.component_manifests.map do |component_manifest|
          component_manifest.stats.except([:proposals_accepted])
                            .filter(conditions)
                            .with_context(published_components)
                            .map { |stat_title, stat_number| [component_manifest.name, stat_title, stat_number] }.flatten
        end
      end

      def process_followers_stats(conditions)
        Decidim.stats.only([:followers_count])
               .filter(conditions)
               .with_context(participatory_process)
               .map { |stat_title, stat_number| [participatory_process.manifest.name, stat_title, stat_number] }
      end

      def published_components
        @published_components ||= Component.where(participatory_space: participatory_process).published
      end
    end
  end
end