# frozen_string_literal: true

require 'json'

# rubocop:disable Metrics/BlockLength because this is how an ActiveSupport
#   concern looks like
module Immoscout
  module Models
    module Concerns
      module Renderable
        extend ActiveSupport::Concern

        included do
          def as_json
            wrapped? ? to_json_wrapped : to_json_unwrapped
          end

          def to_json
            as_json.to_json
          end
          alias_method :to_s, :to_json

          private

          def wrapped?
            self.class.try(:json_wrapper)
          end

          # rubocop:disable Metrics/PerceivedComplexity because this is the
          #   bare minimum logic
          # rubocop:disable Metrics/MethodLength dito
          # rubocop:disable Metrics/CyclomaticComplexity dito
          def to_h
            self.class.properties.each_with_object({}) do |(key, value), memo|
              # skip if it's readonly and should not be exposed in #as_json
              readonly = value.fetch(:readonly, false)
              next if readonly.try(:call, self) || readonly == true

              # use :alias instead of key as json-key
              property = value.fetch(:alias, key)
              # use :default if present AND value is nil
              rendered = send(key) || value.fetch(:default, nil)
              memo[property] = \
                if rendered.is_a?(Array)
                  rendered.map do |elem|
                    elem.try(:as_json) || elem
                  end
                else
                  rendered.try(:as_json) || rendered
                end
              memo
            end
          end
          # rubocop:enable Metrics/PerceivedComplexity
          # rubocop:enable Metrics/MethodLength
          # rubocop:enable Metrics/CyclomaticComplexity

          def to_json_wrapped
            { self.class.try(:json_wrapper) => to_json_unwrapped }
          end

          def to_json_unwrapped
            to_h
              .compact
              .stringify_keys
              .deep_transform_keys { |key| key.camelize :lower }
          end
        end

        class_methods do
        end
      end
    end
  end
end
# rubocop:enable Metrics/BlockLength