#!/usr/bin/ruby

require 'date'
require 'rexml/document'
require 'bushrating'
require 'SVG/Graph/TimeSeries'
include REXML

class BushOut
  def initialize stream
    STDERR.puts "Parsing document"
    t = Time.now
    doc = Document.new(stream)
    t = Time.now - t
    STDERR.puts "Parsed #{stream.length/1000}kb stream in #{t} seconds.  Checking polls."
    
    @polls = XPath.match( doc, '/popularity/poll' )
  end
    
  def dateToFraction( date )
    y,d = date.ord
    y + (d.to_f/365)
  end
  
  def getJD( date ) 
    date.gsub!(/\*/, "")
    case date
    when %r{^(\d+)/(\d+)-(\d+)/(\d+)$}
      y = $4.to_i
      y += 2000 if y<2000
      return Date.new( y, $1.to_i, ($2.to_i+$3.to_i)/2 )
    when %r{^(\d+)/(\d+)-(\d+)/(\d+)/(\d+)$}
      y = $5.to_i
      y += 2000 if y<2000
      d1 = Date.new( y, $1.to_i, $2.to_i )
      d2 = Date.new( y, $3.to_i, $4.to_i )
      return (d1 + ((d2-d1)/2))
    when %r{^(\d+)/(\d+)/(\d+)-(\d+)/(\d+)/(\d+)$}
      y1 = $3.to_i
      y1 += 2000 if y1<2000
      y2 = $6.to_i
      y2 += 2000 if y2<2000
      d1 = Date.new( y1, $1.to_i, $2.to_i )
      d2 = Date.new( y2, $4.to_i, $5.to_i )
      return (d1 + ((d2-d1)/2))
    when %r{^(\d+)/(\d+)/(\d+)$}
      y = $3.to_i
      y += 2000 if y<2000
      return Date.new( y, $1.to_i, $2.to_i )
    when %r{^(\d+)/(\d+)$}
      y = $2.to_i
      y += 2000 if y<2000
      return Date.new( y, $1.to_i, 15 )
    end
  end
  
  def process
    STDERR.puts "Processing..."
    curdate = Time.now.strftime("+%Y/%j")
    graph = SVG::Graph::TimeSeries.new( 
      :width => 640,
      :height => 640,
      :graph_title => "BushMeter, #{curdate}",
      :show_graph_title => true,
      :no_css => true,
      :key => true,
      :key_position => :bottom,
      :scale_x_integers => true,
      :scale_y_integers => true,
      :scale_y_divisions => 10,
      :show_data_labels => false,
      :show_x_guidelines => false,
      :show_x_title => true,
      :x_title => "Time",
      :show_y_title => true,
      :y_title => "%",
      :y_title_text_direction => :bt,
      #:stagger_x_labels => true,
      :x_label_format => "%m/%Y",
      :timescale_divisions => "6 months",
      :add_popups => false,
      :popup_format => "%m/%d/%y",
      :show_data_points => false,
      :show_data_values => false,
      #:area_fill => true,
      :min_y_value => 0
    )
    @polls.each do |poll|
      source = poll.elements["source"].text
			source = source.length > 80 ? source[0,80]+"..." : source
      data = []
      XPath.match(poll, 'instance').each do |instance|
        date = instance.elements['date'].text
        approval = instance.elements['approve'].text
        if approval.to_i > 0
          d = getJD( date )
          if d
            data << d.to_s
            data << approval.to_i
          end
        end
      end
      STDERR.puts "Got #{data.length} data points"
      graph.add_data( :data => data, :title => source )
    end
    STDERR.puts "Burning..."
		rv = graph.burn
		graph.width=300
		graph.height=200
		graph.key=false
		graph.show_x_labels=false
		graph.show_x_title=false
		graph.show_y_labels=false
		graph.show_y_title=false
		graph.show_graph_title = false
		File.open("thumb.svg", "w") {|f| f.puts graph.burn}
    return rv
  end
end

if $0 == __FILE__
  unless false and File.exists? "temp.txt"
    bs = BushSucker.new( true )
    data = bs.get_data
    File.open( "temp.txt", "w" ) {|fout| fout.print data}
  else
    data = IO.read( "temp.txt" )
  end
  bo = BushOut.new( data )
  puts bo.process
end