# Meant to be applied on top of a controller that implements
# Blacklight::SolrHelper. Will inject range limiting behaviors
# to solr parameters creation. 
require 'blacklight_range_limit/segment_calculation'
module BlacklightRangeLimit
  module ControllerOverride
    include SegmentCalculation
    extend ActiveSupport::Concern
  
    included do
      solr_search_params_logic << :add_range_limit_params
      helper_method :range_config
  
      
      
      unless BlacklightRangeLimit.omit_inject[:view_helpers]
        helper BlacklightRangeLimit::ViewHelperOverride
        helper RangeLimitHelper
      end
  
      before_filter do |controller|
        unless BlacklightRangeLimit.omit_inject[:excanvas]
               
          # canvas for IE. Need to inject it like this even with asset pipeline
          # cause it needs IE conditional include. view_context hacky way
          # to get asset url helpers. 
          controller.extra_head_content << ('<!--[if lt IE 9]>' + view_context.javascript_include_tag("flot/excanvas.min.js") + ' <![endif]-->').html_safe
        end
      end
    end
  
    # Action method of our own!
    # Delivers a _partial_ that's a display of a single fields range facets.
    # Used when we need a second Solr query to get range facets, after the
    # first found min/max from result set. 
    def range_limit
      solr_field = params[:range_field] # what field to fetch for
      start = params[:range_start].to_i
      finish = params[:range_end].to_i
      
      solr_params = solr_search_params(params)
  
      # Remove all field faceting for efficiency, we won't be using it.
      solr_params.delete("facet.field")
      solr_params.delete("facet.field".to_sym)
      
      add_range_segments_to_solr!(solr_params, solr_field, start, finish )
      # We don't need any actual rows or facets, we're just going to look
      # at the facet.query's
      solr_params[:rows] = 0
      solr_params[:facets] = nil
      # Not really any good way to turn off facet.field's from the solr default,
      # no big deal it should be well-cached at this point.
      
      @response = Blacklight.solr.find( solr_params )
      
      render('blacklight_range_limit/range_segments', :locals => {:solr_field => solr_field})      
    end
    
    # Method added to solr_search_params_logic to fetch
    # proper things for date ranges. 
    def add_range_limit_params(solr_params, req_params)    
       ranged_facet_configs = 
         blacklight_config.facet_fields.select { |key, config| config.range } 
       # In ruby 1.8, hash.select returns an array of pairs, in ruby 1.9
       # it returns a hash. Turn it into a hash either way.  
       ranged_facet_configs = Hash[ ranged_facet_configs ] unless ranged_facet_configs.kind_of?(Hash)
       
       ranged_facet_configs.each_pair do |solr_field, config|
        solr_params["stats"] = "true"
        solr_params["stats.field"] ||= []
        solr_params["stats.field"] << solr_field    
      
        hash =  req_params["range"] && req_params["range"][solr_field] ?
          req_params["range"][solr_field] :
          {}
          
        if !hash["missing"].blank?
          # missing specified in request params
          solr_params[:fq] ||= []
          solr_params[:fq] << "-#{solr_field}:[* TO *]"
          
        elsif !(hash["begin"].blank? && hash["end"].blank?)
          # specified in request params, begin and/or end, might just have one
          start = hash["begin"].blank? ? "*" : hash["begin"]
          finish = hash["end"].blank? ? "*" : hash["end"]
  
          solr_params[:fq] ||= []
          solr_params[:fq] << "#{solr_field}: [#{start} TO #{finish}]"
          
          if (config.segments != false && start != "*" && finish != "*")
            # Add in our calculated segments, can only do with both boundaries.
            add_range_segments_to_solr!(solr_params, solr_field, start.to_i, finish.to_i)
          end
          
        elsif (config.segments != false &&
               boundaries = config.assumed_boundaries)
          # assumed_boundaries in config
          add_range_segments_to_solr!(solr_params, solr_field, boundaries[0], boundaries[1])
        end
      end
      
      return solr_params
    end
  
    # Returns range config hash for named solr field. Returns false
    # if not configured. Returns hash even if configured to 'true'
    # for consistency. 
    def range_config(solr_field)    
      field = blacklight_config.facet_fields[solr_field]
      return false unless field.range

      config = field.range
      config = {} if config === true

      config
    end
  end
end