module Yelp4r
  class Categories
    
    attr_accessor :parse_url
    
    def initialize
      @parse_url = "http://www.yelp.com/developers/documentation/category_list"
    end
    
    def list
      require 'nokogiri'
      require 'open-uri'
      doc = Nokogiri::HTML(open(@parse_url))
      html = doc.at("ul.attr-list")
      neighborhoods = process_list(html)
      return neighborhoods
    end
    
    def options_from_list(selected = [])
      selected_opts = selected.collect {|s| s.strip}
      process_options(list, selected_opts)
    end
    
    private
    
    def process_list(item)
      item.children.find_all{|t| t.name == "li"}.map do |child|
        unless child.inner_text.nil?
          if child.next_sibling
            next_list = child.next_sibling.name == "ul" ? child.next_sibling : child.next_sibling.next_sibling
          end
          if next_list && !next_list.children.find_all{|c| c.name == "li"}.empty?
            str_vals = decode_string(child.inner_text)
            {str_vals[2] => {:display => str_vals[1], :children => process_list(next_list)}}
          elsif child.name == "li"
            str_vals = decode_string(child.inner_text)
            {str_vals[2] => {:display => str_vals[1]}}
          end
        end
      end
    end
    
    def decode_string(str)
      /(.*)\s\(([^\)]*)/.match(str)
    end
    
    def process_options(item, selected, depth = 0, options = [])
      if item.is_a?(Hash)
        depth += 1
        item.each do |key, val|
          opt_selected = selected.include?(key) ? ' selected="selected"' : ''
          options << %(<option value="#{key}"#{opt_selected}>#{option_prefix(depth)}#{val[:display]}</option>)
          process_options(val[:children], selected, depth, options) if val[:children]
        end
        depth -= 1
      elsif item.is_a?(Array)
        item.each do |i|
          process_options(i, selected, depth, options)     
        end
      end
      return options
    end
    
    def option_prefix(depth)
      s = ""
      if depth > 1
        (depth - 1).times do 
          s += "&nbsp;-"
        end
        s += "&nbsp;"
      end
      return s
    end
    
  end
end