module SimpleSearch
  module ViewHelper

		# Example:
		#
		#   <%= order_by :name %>
		#   <%= order_by :name, 'Company Name' %>
		#   <%= order_by :name, 'Company Name', :class=>'bold' %>
		def order_link(attr, name=nil, html_options={})
			raise Exception, "must be used in a view" unless (request.fullpath && request.parameters)

			# check if order_by is in an url array
			matches = request.fullpath.match Regexp.new("[\&\?]([a-z_]+)\\[order_by\\]=") # &array[order_by]
			order_arr_key = (matches && matches.length == 2) ? matches[1] : nil

			# get order_by value
			order_by_value = order_arr_key ? request.parameters[order_arr_key][:order_by] : request.parameters[:order_by]
      if order_by_value
        order_by_col, current_order = order_by_value.split(" ")
      else
        order_by_col, current_order = attr, nil
      end

			# determine next order
			next_order = {nil=>'asc', 'asc'=>'desc', 'desc'=>'asc'}[current_order]
		
			# build new url params
			new_url_params = if order_arr_key
				old_arr = request.parameters[order_arr_key]
				new_arr = old_arr.merge(:order_by => "#{order_by_col} #{next_order}")
				request.parameters.merge(order_arr_key => new_arr)
			else
				request.parameters.merge(:order_by => "#{order_by_col} #{next_order}" )
			end

			# build link text
			name ||= attr.to_s.humanize.titleize.strip
			order_indicator = {nil=>'', 'asc'=>'&#9650;', 'desc'=>'&#9660;'}[current_order]
			link_text = "#{name} #{order_indicator}".strip

			link_to link_text, new_url_params, html_options
		end

		# 
		# Returns page related properties in hash
		#
		def page_properties(arel)
			total_rows = arel.limit(1000000).offset(0).count

			# check if page is in an url array
			matches = request.fullpath.match Regexp.new("\&([a-z_]+)\\[page|page_by\\]=") # &array[page]
			page_arr_key = (matches && matches.length == 2) ? matches[1] : nil

			# get current page value 
			page = page_arr_key ? request.parameters[page_arr_key][:page] : request.parameters[:page]
			page ||= 1 
      page = page.to_i

			page_by = page_arr_key ? request.parameters[page_arr_key][:page_by] : request.parameters[:page_by]
			page_by ||= 30 
      page_by = page_by.to_i

			last_page = total_rows / page_by.to_i 
			last_page += 1 if total_rows % page_by.to_i != 0
			{
				:total_rows => total_rows,
				:last_page => last_page,
				:current_page => (page || 1).to_i,
				:rows_per_page => (page_by || 30).to_i,
				:page_arr_key => page_arr_key
			}
		end

		# 
		# Returns a url params in hash for the page number given
		#
		def page_params(page_num, page_arr_key=nil)
			params = if page_arr_key
				old_arr = request.parameters[page_arr_key].with_indifferent_access
				request.parameters.merge(page_arr_key => old_arr.merge(:page => page_num) )
			else
				request.parameters.merge(:page => page_num )
			end
      params.with_indifferent_access
		end

		# 
		# Returns page url params in hash with the page number as key
		#
		def page_url_params(arel, num_pages=5)
			page_props = page_properties(arel)
			num_bf_af = (num_pages-1)/2
			current_page = page_props[:current_page]
			last_page    = page_props[:last_page]

			page_numbers = [1, last_page]
			page_numbers << ([current_page-num_bf_af,1].max..[current_page+num_bf_af,last_page].min).to_a
			page_numbers << last_page
			page_numbers = page_numbers.flatten.uniq.sort

			page_url_params = {}
			for num in page_numbers
				page_url_params[num] = page_params(num, page_props[:page_arr_key])
			end

			page_url_params
		end

		def page_urls(arel, http_options={})
			page_urls = []
			prev_page = 0	
			page_url_params(arel).each { |page, url_params|
				if page.to_i > (prev_page+1) # page number jumped up, need to have some indicator
					page_urls << "<span class='filler'>...</span>"
				end
				page_urls << link_to(page, url_params, http_options)
        prev_page = page
			}
      page_urls
		end

	end
end