# frozen_string_literal: true

module Referator
  class Footnotes
    attr_reader :config

    def initialize(config)
      self.config = config

      @references = {}
    end

    def make_ref(category:, id:)
      category = category.to_sym if category.instance_of? String
      config.categories.exists! category
      @references[category] ||= []
      @references[category].each do |reference|
        return reference if reference.category == category && reference.id == id
      end
      reference = config.repo[category, id]
      @references[category] << reference
      render_cite_sup(category:, id:)
    end

    def fetch_footnotes = notes

    def fetch_note(category, id)
      category = category.to_sym if category.instance_of? String
      config.categories.exists! category
      index = 0
      config.categories.names.each do |cur_category|
        (@references[cur_category] ||= []).each do |reference|
          index += 1
          next if cur_category != category

          return Note.new index, reference if reference.id == id
        end
      end
      raise 'Unused note'
    end

    def render_footnotes
      config.scripts.run(
        :default,
        **script_vars(
          template: :footnotes,
          notes: notes.to_json,
        ),
      )
    end

    def render_cite_sup(category:, id:)
      category = category.to_sym if category.instance_of? String
      note = notes.flat_map(&:last).find do |curr_note|
        curr_note[:category] == String(category).to_sym &&
          curr_note[:id] == String(id)
      end
      raise 'Unknown note' if note.nil?

      config.scripts.run(
        :default,
        **script_vars(
          template: :cite_sup,
          note: note.to_json,
        ),
      )
    end

  private

    def config=(config)
      unless config.instance_of? Config
        raise TypeError, "Expected #{Config}, got #{config.class}"
      end

      @config = config
    end

    def script_vars(template: 'null',
                    note: 'null',
                    notes: 'null')
      { template:, notes:, note: }.freeze
    end

    def notes
      index = 0

      config.categories.names.to_h do |category|
        [
          category,
          (@references[category] ||= [])
            .map { |reference| Note.new (index += 1), reference }
            .map(&:to_h)
            .freeze,
        ]
      end.freeze
    end
  end
end