module CodeRay
module Encoders

	# Makes a statistic for the given tokens.
	class Statistic < Encoder

		include Streamable
		register_for :stats, :statistic

		attr_reader :type_stats, :real_token_count

	protected
		
		TypeStats = Struct.new :count, :size

		def setup options
			@type_stats = Hash.new { |h, k| h[k] = TypeStats.new 0, 0 }
			@real_token_count = 0
		end

		def generate tokens, options
			@tokens = tokens
			super
		end
		
		def text_token text, kind
			@real_token_count += 1 unless kind == :space
			@type_stats[kind].count += 1
			@type_stats[kind].size += text.size
			@type_stats['TOTAL'].size += text.size
		end
		
		# TODO Hierarchy handling
		def block_token action, kind
			#@content_type = kind
			@type_stats['open/close'].count += 1
		end

		def token text, kind
			super
			@type_stats['TOTAL'].count += 1
		end

		STATS = <<-STATS

Code Statistics

Tokens            %8d
  Non-Whitespace  %8d
Bytes Total       %8d

Token Types (%d):
  type                     count     ratio    size (average)
-------------------------------------------------------------
%s
			STATS
# space                    12007   33.81 %     1.7
		TOKEN_TYPES_ROW = <<-TKR
  %-20s  %8d  %6.2f %%   %5.1f
			TKR

		def finish options
			all = @type_stats['TOTAL']
			all_count, all_size = all.count, all.size
			@type_stats.each do |type, stat|
				stat.size /= stat.count.to_f
			end
			types_stats = @type_stats.sort_by { |k, v| [-v.count, k.to_s] }.map do |k, v|
				TOKEN_TYPES_ROW % [k, v.count, 100.0 * v.count / all_count, v.size]
			end.join
			STATS % [
				all_count, @real_token_count, all_size,
				@type_stats.delete_if { |k, v| k.is_a? String }.size,
				types_stats
			]
		end
		
	end

end
end