require 'rubygems'
require 'scrobbler'
require 'active_support'

$DEBUG = 1

##
##  HACK IT UP!
##
module Scrobbler
	class Base
		class << self
			#  last.fm requires us to wait for at least one second between requests, so let's do that.
			def wait
				sleep( 1 )
			end
		end
	end
	
	class Artist
		class << self
			alias :old_new_from_xml :new_from_xml

			def new_from_xml( xml, doc = nil )
				a = old_new_from_xml( xml, doc = nil )
				a.playcount = a.playcount.to_i
				a.chartposition = a.chartposition.to_i
				a
			end
		end
	end
	
	class User
		alias :old_weekly_artist_chart :weekly_artist_chart

		def weekly_chart_list
			self.class.wait
			
			doc = self.class.fetch_and_parse( "#{api_path}/weeklychartlist.xml" )
			(doc/:chart).collect{ |el| Week.new( el[ :from ], el[ :to ], self ) }
		end
		
		def weekly_artist_chart( from = nil, to = nil )
			self.class.wait

			old_weekly_artist_chart( from ? from.to_i : nil, to ? to.to_i : nil )
		end
	end
end


##
##  DE-FINE
##
class Week
	attr_reader :from, :to, :artists
	
	def initialize( from, to, user )
		@from = from
		@to = to

		get_artist_data( user )
	end
	
	def get_artist_data( user )
		filename_for_data = "data.#{user.username}.#{from.to_i}.dmp"

		begin
			if not File.exists?( filename_for_data )
				File.open( filename_for_data, "w" ) do |f|
					puts "Saving data from #{filename_for_data}" if $DEBUG
				
					f << Marshal.dump( @artists = user.weekly_artist_chart( @from, @to ) )
				end
			else
				File.open( filename_for_data, "r" ) do |f|
					puts "Loading data from #{filename_for_data}" if $DEBUG

					@artists = Marshal.load( f )
				end			
			end

		rescue EOFError => e
			#  Catch data files which we interrupted the creation of.
			File.delete( filename_for_data )
			retry
		end
	end
	
	def total_plays
		@total_plays ||= @artists.inject( 0 ) { |sum, artist| sum += artist.playcount }
	end
end



##
##  GET THE DATA!
##
user = Scrobbler::User.new( "carldr" )
data = user.weekly_chart_list

puts data.size
#  data.delete_if{ |w| w.total_plays < 10 }
puts data.size

unique_artists_and_total_plays = []
data.sort{ |a,b| a.from <=> b.from }.each do |week|
	week.artists.sort{ |a,b| a.chartposition <=> b.chartposition }.each do |artist|
		if not unique_artists_and_total_plays.select{ |a| a[ :name ] == artist.name }.size > 0
			unique_artists_and_total_plays << { :name => artist.name, :plays => artist.playcount }
		else
			unique_artists_and_total_plays.select{ |a| a[ :name ] == artist.name }.first[ :plays ] += artist.playcount
		end
	end
end

unique_artists_and_total_plays.delete_if{ |a| a[ :plays ] < 10 }

puts "Number of unique artists : #{unique_artists_and_total_plays.size}"

puts unique_artists_and_total_plays.inspect


unique_artist_names = unique_artists_and_total_plays.collect{ |ua| ua[ :name ] }


sums = Hash.new( 0 )
unique_artists_and_total_plays.each do |ua|
	data.each do |week|
		sums[ week ] += week.artists.select{ |a| a.name == ua[ :name ] }.inject( 0 ) { |sum, a| sum += a.playcount }
	end
end
most_plays_in_a_week = sums.sort{ |a,b| b[1] <=> a[1] }.first[1]
puts "Most plays in a week of good artists : #{most_plays_in_a_week}"

puts
puts
puts

christmas_tree = []
ua = unique_artists_and_total_plays.dup
while ua.size > 0
	christmas_tree.push( ua.shift )
	christmas_tree.unshift( ua.shift ) if ua.size > 0
end
puts christmas_tree.inspect

##
##  GRAPH IT UP!
##
WIDTH = 10000.0
HEIGHT = 1600.0

File.open( "#{user.username}.svg", "w" ) do |f|
	f.write <<-EOS
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg width="#{WIDTH}" height="#{HEIGHT}" version="1.1" xmlns="http://www.w3.org/2000/svg">
EOS
	
	
	text_data = []
	
	unique_artists_and_total_plays.reverse.each do |ua|
		artistno = unique_artists_and_total_plays.index( ua )
		colour_off = artistno * ( 255.0 / unique_artist_names.size )
		week_data = []

		max_week = nil
		max_week_size = 0
		max_week_index = 0

		data.each_with_index do |week, weekno|
			amount_under = 0
			this_size = 0
			
			unique_artists_and_total_plays.each do |all_ua|
				artist = week.artists.select{ |a| a.name == all_ua[ :name ] }.first

				if all_ua[ :name ] == ua[ :name ]
					this_size = artist ? artist.playcount : 0
					break
				else
					amount_under += artist ? artist.playcount : 0
				end
			end
			
			week_data << { :total_plays => week.total_plays, :under => amount_under, :size => this_size, :total_size => week.artists.select{ |a| unique_artist_names.include?( a.name ) }.inject( 0 ) { |sum, a| sum += a.playcount } }
			
			if this_size > max_week_size
				max_week_size = this_size
				max_week = week_data.last
				max_week_index = weekno
			end
		end

		puts ua[ :name ]
		puts week_data.inspect

		text_data << { :ua => ua, :week_data => max_week.dup, :weekno => max_week_index }

		colour = "#" + ( 255 - colour_off ).to_i.to_s(16).rjust(2, "0") + ( ( 255 - colour_off ) / 3 ).to_i.to_s(16).rjust(2, "0") + colour_off.to_i.to_s(16).rjust(2, "0")
		
		f << "<path style='stroke: #{colour}; stroke-width: 1; fill: #{colour};' d='"
		week_data.each_with_index do |weekly_data, i|
			x = ( WIDTH / data.size * i ).to_i
			y = ( HEIGHT / 2 / most_plays_in_a_week * ( weekly_data[ :under ] ) ).to_i
			yoff = ( HEIGHT / 2 ) + ( ( HEIGHT / 2 ) * weekly_data[ :total_plays ].to_f / most_plays_in_a_week )
			yoff = 0
			
			if i == 0
				f << "M#{-( WIDTH / data.size / 2).to_i} #{( yoff+y ).to_i} "
			else
				f << "S#{( x-( WIDTH / data.size / 2 ) ).to_i} #{( yoff+y ).to_i} #{x.to_i} #{( yoff+y ).to_i} "
			end
		end

		week_data.reverse.each_with_index do |weekly_data, i|
			x = ( WIDTH / data.size * ( data.size-i-1 ) ).to_i
			y = ( HEIGHT / 2 / most_plays_in_a_week * ( weekly_data[ :under ] + weekly_data[ :size ] ) ).to_i
			yoff = ( HEIGHT / 2 ) + ( ( HEIGHT / 2 ) * weekly_data[ :total_plays ].to_f / most_plays_in_a_week )
			yoff = 0
			
			if i == 0
				f << "L#{x.to_i} #{( yoff+y ).to_i} "
			else
				f << "S#{( x+( WIDTH / data.size / 2 ) ).to_i} #{( yoff+y ).to_i} #{x.to_i} #{( yoff+y ).to_i} "
			end
		end
		
		f << "Z' />\n"
	end
	
	text_data.each do |td|
		next if td[ :weekno ] == data.size - 1 or td[ :weekno ] == 0  # Lets not display band names in the first or last weeks.

		weekly_data = td[ :week_data ]
			
		x = ( WIDTH / data.size * td[ :weekno ] ).to_i
		y = ( HEIGHT / 2 / most_plays_in_a_week * ( weekly_data[ :under ] + weekly_data[ :size ] / 2 ) ).to_i
		yoff = ( HEIGHT / 2 ) + ( ( HEIGHT / 2 ) * weekly_data[ :total_plays ].to_f / most_plays_in_a_week )
		yoff = 0

		f << "<text x='#{x.to_i}' y='#{( yoff+y+3 ).to_i}' style='font-family: Helvetica; font-size: #{[ HEIGHT / 3000.0 * weekly_data[ :size ], HEIGHT / 200 ].max}px; text-align: center; text-anchor: middle; fill: #fff; opacity: 0.60;'>#{td[ :ua ][ :name ]}</text>"
	end
	
f.write <<-EOS
</svg>
	EOS
end