module MultiSolr::RailsFormRenderHelper


  # Generieren der HML-Form-Felder (input/select/..) für den angegeben Filter
  # Params:
  #   form:         das Rails-Form-Object, dieses MUSS als Object eine MultiSolr::SearchRequest-Instance haben
  #   filter_name:  Name des Filters als Symbol (die SearchRequest-Instance im Form muss diesen Filter kennen)
  #   options:      optionale Formular-Input-Feld-Options. Beschreibung => siehe jeweilige Beschreibung je Filter-Methode
  #                 Diese werden i.d.R. an die Rails-Form-Methode 'text_field' weitergegeben.
  #
  # returns:  HTML-Code des Input-Feldes als String
  def render_solr_filter_for_form form, filter_name, options={}
    cur_options = options.clone
    search_request = form.object
    filter = search_request.class.possible_filters[filter_name]
    raise "unknown filter: #{filter_name}" if filter.nil?
    label = cur_options.delete(:label) || filter.label
    render_method = "render_#{filter.class.to_s.underscore}"
    render_method.gsub!("/", '_')
    render_method.gsub!("multi_solr_", '')
    "<label>#{label}</label>".html_safe + send(render_method, form, filter, cur_options)
  end


  # generiert für einen SolrFilterSimple einen input-tag vom typ text
  # mit der css-class "simple"
  def render_solr_filter_simple form, filter, options
    add_class options, 'simple'
    form.text_field "filter_#{filter.name}", options
  end


  # generiert für einen SolrFilterSimple einen input-tag vom typ text
  # mit der css-class "datepicker"
  # Diese css-Klasse kann dann als jQuery-Selector für datepicker genutzt werden
  def render_solr_filter_date form, filter, options
    add_class options, 'datepicker'
    form.text_field "filter_#{filter.name}", options
  end


  def render_solr_filter_date_range form, filter, options
    add_class options, 'datepicker'
    value = form.object.send("filter_#{filter.name}")
    return nil if value.blank? || !value.is_a?(Hash) || value.empty?
    from = value["#{filter.name}_from"]
    to = value["#{filter.name}_to"]
    date_range = Struct.new("#{filter.name}_from".to_sym, "#{filter.name}_to".to_sym).new from,to
    form.fields_for "filter_#{filter.name}", date_range do |fields_form|
      fields_form.template.concat("<label>ab</label>".html_safe)
      fields_form.template.concat(fields_form.text_field("#{filter.name}_from", options))
      fields_form.template.concat("<label>bis</label>".html_safe)
      fields_form.template.concat(fields_form.text_field("#{filter.name}_to", options))
    end
  end



  def render_solr_filter_collection form, filter, options
    add_class options, 'collection'
    core_handler = options.delete(:core_handler)
    context = options.delete(:context)
    data = filter.collection_data(core_handler, context)
    form.select "filter_#{filter.name}", data, options
  end


  def render_solr_filter_free_query form, filter, options
    add_class options, 'free_query'
    form.text_field "filter_#{filter.name}", options
  end


  private


  def add_class options, css_class_name
    css_class = options[:class]
    css_class = css_class.nil? ? css_class_name : "#{css_class} #{css_class_name}"
    options[:class] = css_class
  end


end