class Header
	attr_reader :kind, :num_faces, :zoom, :num_points, :unk1

	def initialize(kind, num_faces, zoom, num_points, unk1)
		@kind = kind
		@num_faces = num_faces
		@zoom = zoom
		@num_points = num_points
		@unk1 = unk1
	end

	def Header.read(f)
		buf = f.read(18)

		items = buf.unpack("vVeVV")

		Header.new(*items)
	end
end

class Point
	attr_reader :id, :x, :y, :z

	def initialize(id, x, y, z)
		@id = id
		@x = x
		@y = y
		@z = z
	end

	def Point.read(f)
		items = f.read(16).unpack("Veee")

		Point.new(*items)
	end
end

# each face stores a reference to the used texture.
# this includes the name of the texture (eg mod_001)
class Face
	attr_accessor :id, :kind

	def initialize
		@id = 0
		@kind = 0
	end

	def self.read(f)
		face = Face.new

		# read at 0x901e1
		face.id = f.read(4).unpack('V').first

		# read at 0x901f4 and again at 0x88554
		face.kind = f.read(2).unpack('v').first

		# read at 0x8d563. UNKNOWN.
		f.read 24

		# read at 0xb948e.
		# is the same value for every face in a given module.
		buf0 = f.read 4

		# read at 0xb949e. not evaluated.
		f.read 4

		# read at 0xb94ae.
		# is the same value for every face in a given module.
		buf1 = f.read 4

		# read at 0xb94be.
		buf2 = f.read 4

		# read at 0xb94ce.
		buf3 = f.read 4

		# read at 0xb94de. not evaluated.
		f.read 4

		edi = buf3.unpack('V').first
		#puts "   #{edi}"
		# ^^^ could this be the number of vertices that belong to this face?

		# read at 0xb950b.
		# this might be the the coordinates of the texture rectangle
		# that's to be used by this face. 8 bytes = two ints:
		# eg: x, y
		_ = f.read edi * 8
		#p _.unpack('VV')

		# read real module/texture reference:
		# read at 0x14d9f
		string_length = f.read(4).unpack('V').first

		# read at 0x14dab. not evaluated.
		f.read 4

		# read at 0x14dc7
		tex_name = f.read string_length
		puts "using texture: #{tex_name}"

		# this might be the corners of the face, given as float vectors.
		_ = f.read(4 * 3 * edi)
		p _.unpack('e*')

		face
	end
end

f = File.open(ARGV.shift, 'rb')

header = Header.read(f)

puts "kind: #{header.kind}"
puts "zoom: #{header.zoom}"
puts "#faces: #{header.num_faces}"
puts "#points: #{header.num_points}"
puts "unk1: #{header.unk1}"

points = []
faces = []

header.num_points.times do |i|
	points << Point.read(f)
end

# puts "point IDs:"
# p points.map { |point| point.id }.sort

puts "done reading vertices. file offset: #{ '0x%x' % f.tell }"

header.num_faces.times do |i|
	puts "reading face #{i} at #{ '0x%x' % f.tell}"

	faces << Face.read(f)
end

puts "done reading faces. file offset: #{ '0x%x' % f.tell}"

puts "reading module footer"

# read at 0x902da
f.read 4

# read at 0x902e8. num_faces?
t = f.read(4).unpack('V').first
unless t == header.num_faces
	raise "expected #{header.num_faces}, but got #{t}"
end

# read at 0x902f6. num_faces?
t = f.read(4).unpack('V').first
unless t == header.num_faces
	raise "expected #{header.num_faces}, but got #{t}"
end

8.times do
	raise 'hit eof unexpectedly' if f.eof?

	# read at 0x9037f: each face's ID is read once.
	# maybe this puts the faces in some order?
	# note:
	# only the first four blocks seem to be read.

	f.read header.num_faces * 4
end

puts "file offset: #{ '0x%x' % f.tell}"
puts "at EOF? #{f.eof?}"