#! /usr/bin/env ruby
#
# refererplot - anylize a referer log and generate a flash-based chart.
#
# Copyright (C) 2004 Satoru Takabayashi <satoru@namazu.org> 
#     All rights reserved.
#     This is free software with ABSOLUTELY NO WARRANTY.
#
# You can redistribute it and/or modify it under the terms of 
# the GNU General Public License version 2.
#
require 'mingchart'
require 'cgi'

class RefererPlot
  def initialize (nreferers)
    @hourly_stat = Hash.new
    @referer_stat = Hash.new
    @nreferers = nreferers
    @top_referers = []
    @plot_data = []
  end

  def draw (filename)
    chart = MingChart.new(:flash_font => "EfontSerifB.fdb",
                          :x_time_scale => true,
                          :line_title_font_size => 16,
                          :font_size => 24,
                          :drawing_methods => [:draw_line],
                          :x_time_scale_format => "%m/%d (%H:%M)",
                          :line_titles => @top_referers
                          )
    @nreferers.times {|i| chart.add_data(@plot_data, i + 1) }
    chart.draw
    chart.save(filename)
  end

  # '11/Apr/2004:06:49:01 +0900' => Time
  def parse_apache_time (str)
    if m = %r!^(\d\d)/(\w+)/(\d\d\d\d):(\d\d):(\d\d):(\d\d) !.match(str)
      day  = m[1].to_i
      mon  = Time::RFC2822_MONTH_NAME.index(m[2]) + 1
      year = m[3].to_i
      hour = m[4].to_i
      min  = m[5].to_i
      sec  = m[6].to_i
      Time.mktime(year, mon, day, hour, min, sec)
    else
      raise "unsupported time format #{str}"
    end
  end

  def analyze_log (pattern)
    while line = gets
      if m = line.match(%r!\[(.*?)\] "GET (.*?) HTTP/1\.[01]" 200 \d+ "(.*?)"!)
        time    = parse_apache_time(m[1])
        page    = CGI.unescape(m[2])
        referer = CGI.unescape(m[3])

        if pattern.match(page) and referer != "-" and 
            !referer.match(/#{page}$/)
          key = time.strftime("%Y-%m-%dT%H")
          @hourly_stat[key] ||= Hash.new
          @hourly_stat[key][referer] ||= 0
          @hourly_stat[key][referer] += 1

          @referer_stat[referer] ||= 0
          @referer_stat[referer] += 1
        end
      end
    end
  end

  def complete_stat 
    @top_referers = @referer_stat.keys.sort {|a, b| 
      @referer_stat[b] <=> @referer_stat[a] 
    }[0, @nreferers]

    @top_referers.each {|referer|
      printf("%d\t%s\n", @referer_stat[referer], referer)
    }

    @hourly_stat.keys.sort.each {|timestr|
      time = Time.parse(timestr + ":00:00")
      data = [0] * @nreferers
      @hourly_stat[timestr].each {|referer, count|
        if n = @top_referers.index(referer)
          data[n] = count 
        end
      }
      next unless data.find {|x| x > 0 }
      @plot_data.push([time.to_i] + data)
    }
  end
end

if ARGV.length != 2
  puts "Usage: refererplot PATTERN NREFERERS" 
  exit 0
end

pattern = Regexp.new(ARGV.shift)
nreferers = ARGV.shift.to_i

plot = RefererPlot.new(nreferers)
plot.analyze_log(pattern)
plot.complete_stat
plot.draw("refererplot.swf")