module Godmin
  module Helpers
    module Filters
      def filter_input_tag(name, options)
        case options[:as]
        when :string
          filter_string_tag(name, options)
        when :select
          filter_select_tag(name, options)
        when :multiselect
          filter_multiselect_tag(name, options)
        when :checkboxes
          filter_checkbox_tags(name, options)
        end
      end

      private

      def filter_string_tag(name, _options)
        text_field_tag(
          name,
          default_filter_value(name),
          name: "filter[#{name}]",
          class: "form-control",
          placeholder: translate_scoped("filters.labels.#{name}", default: name.to_s.titleize)
        )
      end

      def filter_select_tag(name, options)
        filter_select_tag_helper(
          name,
          options,
          name: "filter[#{name}]",
          include_blank: true,
          class: "form-control select-tag",
          data: {
            placeholder: translate_scoped("filters.select.placeholder.one")
          }
        )
      end

      def filter_multiselect_tag(name, options)
        filter_select_tag_helper(
          name,
          options,
          name: "filter[#{name}][]",
          multiple: true,
          class: "form-control select-tag",
          data: {
            placeholder: translate_scoped("filters.select.placeholder.many")
          }
        )
      end

      def filter_select_tag_helper(name, options, html_options)
        unless options[:collection].is_a? Proc
          raise "A collection proc must be specified for select filters"
        end

        collection = options[:collection].call

        if collection.is_a? ActiveRecord::Relation
          choices = options_from_collection_for_select(
            collection,
            options[:option_value],
            options[:option_text],
            selected: default_filter_value(name)
          )
        else
          choices = options_for_select(
            collection,
            selected: default_filter_value(name)
          )
        end

        select_tag(name, choices, html_options)
      end

      def filter_checkbox_tags(name, options)
        unless options[:collection].is_a? Proc
          raise "A collection proc must be specified for checkbox filters"
        end

        collection = options[:collection].call

        collection.map do |item|
          text, value = if !item.is_a?(String) && item.respond_to?(:first) && item.respond_to?(:last)
            [item.first.to_s, item.last.to_s]
          else
            [item.to_s, item.to_s]
          end

          is_checked = default_filter_value(name) ? default_filter_value(name).include?(value) : false

          content_tag :div, class: "checkbox" do
            label_tag("#{name}_#{value}") do
              check_box_tag("filter[#{name}][]", value, is_checked, id: "#{name}_#{value}") << text
            end
          end
        end.join("\n").html_safe
      end

      def default_filter_value(name)
        params[:filter] ? params[:filter][name] : nil
      end
    end
  end
end