#
# Adds Filterrific view helpers to ActionView instances
#
module Filterrific
  module ActionViewExtension
    include HasResetFilterrificUrlMixin

    # Sets all options on form_for to defaults that work with Filterrific
    # @param record [Filterrific] the @filterrific object
    # @param options [Hash] standard options for form_for
    # @param block [Proc] the form body
    def form_for_filterrific(record, options = {}, &block)
      options[:as] ||= :filterrific
      options[:html] ||= {}
      options[:html][:method] ||= :get
      options[:html][:id] ||= :filterrific_filter
      options[:url] ||= url_for(
        controller: controller.controller_name,
        action: controller.action_name
      )
      form_for(record, options, &block)
    end

    # Renders a spinner while the list is being updated
    def render_filterrific_spinner
      %(
        <span class="filterrific_spinner" style="display:none;">
          #{image_tag("filterrific/filterrific-spinner.gif", alt: "", role: "presentation")}
        </span>
      ).html_safe
    end

    # Renders a link which indicates the current sorting and which can be used to
    # toggle the list sorting (set column and direction).
    #
    # NOTE: Make sure that this is used in the list partial that is re-rendered
    # when the filterrific params are changed, so that the filterrific params in
    # the URL are always current.
    #
    # NOTE: Currently the filterrific_sorting_link is not synchronized with a
    # SELECT input you may have in the filter form for sorting. We recommend you
    # use one or the other to avoid conflicting sort settings in the UI.
    #
    # @param filterrific [Filterrific::ParamSet] the current filterrific instance
    # @param sort_key [String, Symbol] the key to sort by, without direction.
    #     Example: 'name', 'created_at'
    # @param opts [Hash, optional]
    # @options opts [String, optional] active_column_class
    #     CSS class applied to current sort column. Default: 'filterrific_current_sort_column'
    # @options opts [String, optional] ascending_indicator
    #     HTML string to indicate ascending sort direction. Default: '⬆'
    # @options opts [String, optional] default_sort_direction
    #     Override the default sorting when selecting a new sort column. Default: 'asc'.
    # @options opts [String, optional] descending_indicator
    #     HTML string to indicate descending sort direction. Default: '⬇'
    # @options opts [Hash, optional] html_attrs
    #     HTML attributes to be added to the sorting link. Default: {}
    # @options opts [String, optional] label
    #     Override label. Default: `sort_key.to_s.humanize`.
    # @options opts [String, Symbol, optional] sorting_scope_name
    #     Override the name of the scope used for sorting. Default: :sorted_by
    # @options opts [Hash, optional] url_for_attrs
    #     Override the target URL attributes to be used for `url_for`. Default: {} (current URL).
    def filterrific_sorting_link(filterrific, sort_key, opts = {})
      opts = {
        active_column_class: "filterrific_current_sort_column",
        inactive_column_class: "filterrific_sort_column",
        ascending_indicator: "⬆",
        default_sort_direction: "asc",
        descending_indicator: "⬇",
        html_attrs: {},
        label: sort_key.to_s.humanize,
        sorting_scope_name: :sorted_by,
        url_for_attrs: {},
        as: :filterrific
      }.merge(opts)
      opts.merge!(
        html_attrs: opts[:html_attrs].with_indifferent_access,
        current_sorting: (current_sorting = filterrific.send(opts[:sorting_scope_name])),
        current_sort_key: current_sorting ? current_sorting.gsub(/_asc|_desc/, "") : nil,
        current_sort_direction: if current_sorting
                                  current_sorting.end_with?("_desc") ? "desc" : "asc"
                                end,
        current_sort_direction_indicator: if current_sorting
                                            (current_sorting.end_with?("_desc") ? opts[:descending_indicator] : opts[:ascending_indicator])
                                          end
      )
      new_sort_key = sort_key.to_s
      if new_sort_key == opts[:current_sort_key]
        # same sort column, reverse order
        filterrific_sorting_link_reverse_order(filterrific, new_sort_key, opts)
      else
        # new sort column, default sort order
        filterrific_sorting_link_new_column(filterrific, new_sort_key, opts)
      end
    end

    protected

    # Renders HTML to reverse sort order on currently sorted column.
    # @param filterrific [Filterrific::ParamSet]
    # @param new_sort_key [String]
    # @param opts [Hash]
    # @return [String] an HTML fragment
    def filterrific_sorting_link_reverse_order(filterrific, new_sort_key, opts)
      # current sort column, toggle search_direction
      new_sort_direction = opts[:current_sort_direction] == "asc" ? "desc" : "asc"
      new_sorting = safe_join([new_sort_key, new_sort_direction], "_")
      css_classes = safe_join([
        opts[:active_column_class],
        opts[:html_attrs].delete(:class)
      ].compact, " ")
      new_filterrific_params = filterrific.to_hash
        .with_indifferent_access
        .merge(opts[:sorting_scope_name] => new_sorting)
      url_for_attrs = opts[:url_for_attrs].merge(opts[:as] => new_filterrific_params)
      link_to(
        safe_join([opts[:label], opts[:current_sort_direction_indicator]], " "),
        url_for(url_for_attrs),
        opts[:html_attrs].reverse_merge(class: css_classes, method: :get, remote: true)
      )
    end

    # Renders HTML to sort by a new column.
    # @param filterrific [Filterrific::ParamSet]
    # @param new_sort_key [String]
    # @param opts [Hash]
    # @return [String] an HTML fragment
    def filterrific_sorting_link_new_column(filterrific, new_sort_key, opts)
      new_sort_direction = opts[:default_sort_direction]
      new_sorting = safe_join([new_sort_key, new_sort_direction], "_")
      css_classes = safe_join([
        opts[:inactive_column_class],
        opts[:html_attrs].delete(:class)
      ].compact, " ")
      new_filterrific_params = filterrific.to_hash
        .with_indifferent_access
        .merge(opts[:sorting_scope_name] => new_sorting)
      url_for_attrs = opts[:url_for_attrs].merge(opts[:as] => new_filterrific_params)
      link_to(
        opts[:label],
        url_for(url_for_attrs),
        opts[:html_attrs].reverse_merge(class: css_classes, method: :get, remote: true)
      )
    end
  end
end