#!/usr/local/bin/ruby -w

# Dan Richert 2006
# dan.richert@gmail.com

unless ARGV.length >= 1
	puts "
	summary <text> <depth> <length> <opt: linear_degrade on/off>
	"
	exit
end
	
text = File.open(ARGV[0]||'/usr/share/dict/words', 'r').read
depth = ARGV[1].to_i
len = ARGV[2].to_i
if ARGV[3]=='d': linear_degrade = true end

def csplit(s)
	a = []
	s.each_byte {|b| a.push(b.chr)}
	return a
end

def markov(a, depth)
	h = Hash.new
	a.each_index do |ndx|
		temp = []
		depth.times {|i| temp.push(a[ndx+(i+1)])}
		unless h[a[ndx]]: h[a[ndx]] = [] end
		h[a[ndx]].push(temp)
	end
	return h
end	

while depth>1 
	#puts "\n\n\n+++ depth: #{depth}\n\n\n"
	chars = csplit(text)
	h = markov(chars, depth)
	key = chars[rand(chars.length)]
	section = ''
	if linear_degrade: len += len/8 end
	while section.length < len
		if h[key] 
			selection_ndx = rand(h[key].length)
			selection_arr = h[key][selection_ndx]
			selection_str = selection_arr.join
			section += selection_str
			key = section[section.length-1].chr
		end
	end
	print section[0..len]
	depth -= 1
end
puts "\n\n"