#!/usr/bin/env python3

import ctypes, sys, struct

memory = [0]*65536
here = 0
pointers = {}


def extract_code(code):
  ret = ''
  comment = True
  for i in code.split('\n'):
    if i == '~~~':
      comment = comment == False
    elif not comment:
      ret += i+'\n'
  return ret


ops = [ '..', 'li', 'du', 'dr', 'sw', 'pu',
        'po', 'ju', 'ca', 'cc', 'cj', 're',
        'eq', 'ne', 'lt', 'gt', 'fe', 'st',
        'ad', 'su', 'mu', 'di', 'an', 'or',
        'xo', 'sl', 'sr', 'cp', 'cy', 'io' ]

def comment(a):
  pass

def origin(a):
  global here
  here = int(a)

def intw(a):
  global memory, here
  memory[here] = int(ctypes.c_int32(int(a)).value)
  here += 1

def bundle(a):
  A = ops.index(a[0:2])
  B = ops.index(a[2:4])
  C = ops.index(a[4:6])
  D = ops.index(a[6:8])
  intw((D<<24)+(C<<16)+(B<<8)+A)

def spacer(a):
  global here
  here += int(a)

def sstr(a):
  intw(len(a))
  for c in a:
    intw(ord(c))

def zstr(a):
  for c in a:
    intw(ord(c))
  intw(0)

def ref(a):
  if a in pointers:
    intw(pointers[a])
  else:
    intw(0)

def iref(a):
  if a in pointers:
    intw(-1 * pointers[a])
  else:
    intw(0)

def label(a):
  global pointers
  pointers[a] = here

def rc(code):
  global here
  here = 0
  ops = {
          'c': comment,
          'o': origin,
          'i': bundle,
          'd': intw,
          '*': spacer,
          's': sstr,
          'z': zstr,
          'r': ref,
          'R': iref,
          '-': ref,
          ':': label
  }
  for line in code.split('\n'):
    if ' ' in line.lstrip():
      op,a = line.lstrip().split(' ', 1)
      ops[op](a)

def save_image():
  with open("ilo.rom", "wb") as f:
    f.write(struct.pack('65536i', *memory[:65536]))

def pali(code):
  code = extract_code(code)
  rc(code) #pre processing
  rc(code) #post processing
  print('{} words ({} bytes) used'.format(here, here*4))

if __name__ == '__main__':
  a = sys.argv
  if len(a) > 1:
    with open(a[1], 'r') as code:
      pali(code.read())
      save_image()
  else:
    with open('pali.output', 'w') as f:
      pali(input('paste in Pali code:\n'))
      save_image()