class SuperRandom

# File lib/super_random/services.rb, line 22
def self.atmospheric(n)
  s = Net::HTTP.get(URI(
    "https://www.random.org/integers/?num=#{n}&min=0&max=255&col=1&base=10&format=plain&rnd=new"))
  a = s.strip.split(/\s+/).map{|j|j.to_i}
  raise unless a.length==n
  raise unless a.all?{|i| i.between?(0,255)}
  return a
rescue StandardError
  warn "atmospheric (www.random.org) failed."
  return nil
end

# File lib/super_random/services.rb, line 35
def self.hotbits(n, k='Pseudorandom')
  s = Net::HTTP.get(URI(
    "https://www.fourmilab.ch/cgi-bin/Hotbits.api?nbytes=#{n}&fmt=bin&apikey=#{k}"))
  a = s.bytes
  raise unless a.length==n
  return a
rescue StandardError
  warn "hotbits (www.fourmilab.ch) failed."
  return nil
end

# File lib/super_random/generator.rb, line 7
def initialize
  @first_timeout = 3
  @second_timeout = 6
  @nevermind = true
  @randomness = 0.0
  @services = 0
end

# File lib/super_random/services.rb, line 8
def self.quantum(n)
  s = Net::HTTP.get(URI(
    "https://qrng.anu.edu.au/API/jsonI.php?length=#{n}&type=uint8"))
  a = JSON.parse(s)['data']
  raise unless a.is_a?(Array) and a.length==n
  raise unless a.all?{|i| i.is_a?(Integer) and i.between?(0,255)}
  return a
rescue StandardError
  warn "quantum (qrng.anu.edu.au) failed."
  return nil
end

# File lib/super_random/services.rb, line 2
def self.services
  [:quantum, :atmospheric, :hotbits]
end

# File lib/super_random/generator.rb, line 15
def bytes(n=DEFAULT_BYTES)
  @randomness = 0.0
  @services = 0

  m = SuperRandom.services
  a = Array.new m.length
  t = Array.new m.length
  m.each_with_index do |k,i|
    t[i] = Thread.new{ a[i] = SuperRandom.send(k, n) }
  end

  begin
    Timeout.timeout(@first_timeout) do
      # Initially, would like to get them all.
      t.each{_1.join}
    end
  rescue Timeout::Error
    begin
      Timeout.timeout(@second_timeout) do
        # But at this point,
        # would like to get at least one.
        while a.all?{_1.nil?} and t.any?{_1.alive?}
          Thread.pass
        end
      end
    rescue Timeout::Error
      # If we don't care that we got nothing, go on.
      raise $! unless @nevermind
    end
  end

  r = Array.new n
  n.times{|i| r[i] = SecureRandom.random_number(256)}

  a.each do |b|
    next if b.nil?
    l = b.length
    @randomness += l.to_f/n.to_f
    @services += 1
    n.times{|i|r[i]=(r[i]+b[i%l])%256}
  end

  return r
end

# File lib/super_random/generator.rb, line 60
def hexadecimal(n=DEFAULT_BYTES)
  bytes(n).map{|i|i.to_s(16).rjust(2,'0')}.join
end

# File lib/super_random/generator.rb, line 64
def random_number(scale=1.0, minbytes=6, maxbytes=[minbytes,DEFAULT_BYTES].max)
  case scale
  when Float
    div = minbytes.times.inject(''){|s,i| s+'FF'}.to_i(16)
    den = hexadecimal(minbytes).to_i(16)
    return  scale * den.to_f / div.to_f
  when Integer
    n = n0 = Math.log(scale, 256).ceil
    e = e0 = 256**n
    r = r0 = e0 % scale
    while r > 0
      n0 += 1
      e0 *= 256
      r0 = e0 % scale
      if r0 <= r
        # break if repeating pattern with big enough integer
        break if r0 == r and n0 > minbytes
        r,n,e = r0,n0,e0
      end
      break if n0 >= maxbytes
    end
    max = (e/scale)*scale
    loop do
      number = hexadecimal(n).to_i(16)
      return number % scale if number < max
      # On a relatively small chance that we're above max...
      if @nevermind
        warn "using SecureRandom.random_number(#{scale})"
        return SecureRandom.random_number(scale)
      end
    end
  end
  raise "rand(scale Integer|Float)"
end