# -*- encoding : utf-8 -*-
# All methods in here are 'api' that may be over-ridden by plugins and local
# code, so method signatures and semantics should not be changed casually.
# implementations can be of course.
#
# Includes methods for rendering contraints graphically on the
# search results page (render_constraints(_*))
module Blacklight::RenderConstraintsHelperBehavior

  # Render actual constraints, not including header or footer
  # info. 
  def render_constraints(localized_params = params)
    (render_constraints_query(localized_params) + render_constraints_filters(localized_params)).html_safe
  end
  
  def render_constraints_query(localized_params = params)
    # So simple don't need a view template, we can just do it here.
    if (!localized_params[:q].blank?)
      label = 
        if (localized_params[:search_field].blank? || (default_search_field && localized_params[:search_field] == default_search_field[:key] ) )
          nil
        else
          label_for_search_field(localized_params[:search_field])
        end
    
      render_constraint_element(label,
            localized_params[:q], 
            :classes => ["query"], 
            :remove => url_for(localized_params.merge(:q=>nil, :action=>'index')))
    else
      "".html_safe
    end
  end

  def render_constraints_filters(localized_params = params)
     return "".html_safe unless localized_params[:f]
     content = []
     localized_params[:f].each_pair do |facet,values|
       content << render_filter_element(facet, values, localized_params)
     end 

     return content.flatten.join("\n").html_safe    
  end

  def render_filter_element(facet, values, localized_params)
    facet_config = facet_configuration_for_field(facet)

    values.map do |val|

      render_constraint_element( facet_field_labels[facet],
                  facet_display_value(facet, val), 
                  :remove => url_for(remove_facet_params(facet, val, localized_params)),
                  :classes => ["filter", "filter-" + facet.parameterize] 
                ) + "\n"                 					            
    end
  end

  # Render a label/value constraint on the screen. Can be called
  # by plugins and such to get application-defined rendering.
  #
  # Can be over-ridden locally to render differently if desired,
  # although in most cases you can just change CSS instead.
  #
  # Can pass in nil label if desired.
  #
  # options:
  # [:remove]
  #    url to execute for a 'remove' action  
  # [:classes] 
  #    can be an array of classes to add to container span for constraint.
  # [:escape_label]
  #    default true, HTML escape.
  # [:escape_value]
  #    default true, HTML escape. 
  def render_constraint_element(label, value, options = {})
    render(:partial => "catalog/constraints_element", :locals => {:label => label, :value => value, :options => options})    
  end

end