require 'pp'

class Face < Array
  attr_accessor :width, :height

  def initialize(file)
    header = file.read(8)
    self.width, self.height = header.unpack("LL")
    data = file.read(8 * length)
    data.unpack("D" * length).each do |pixel|
      self << pixel
    end
  end

  def length
    width * height
  end

  def to_h
    {
      #width: width,
      #height: height,
      data: self[0..1]
    }
  end
end

class Faces < Array
  attr_accessor :count, :width, :height, :average
  def initialize(file)
    header = file.read(12)
    self.count, self.width, self.height = header.unpack('LLL')
    (1..count).each do |i|
     self << Face.new(file)
    end
    self.average = Face.new(file)
  end

  def to_h
    {
      count: count,
      #width: width,
      #height: height,
      average: average.to_h,
      data: self.map(&:to_h)
    }
  end
end

def error(faces1, faces2)
  faces1.each_with_index do |face, index|
    otherFace = faces2[index]
    scalar = otherFace[0] / face[0]
    error = 0.0
    face.each_with_index do |v, i|
      error += (v - otherFace[i] / scalar) ** 2
    end
    puts Math.sqrt(error)
  end
end

face1 = nil
face2 = nil

File.open(ARGV[0], 'rb') do |file|
  face1 = Faces.new(file)
end
File.open(ARGV[1], 'rb') do |file|
  face2 = Faces.new(file)
end

puts ARGV[0]
pp face1.to_h
puts ARGV[1]
pp face2.to_h

error(face1, face2)