import os
import sys

from collections import namedtuple

Attribute = namedtuple('Attribute', ['fg', 'bg', 'bold'])

WIDTH = 80
HEIGHT = 25
# ANSI orders the colours black, red, green, yellow, blue, magenta, cyan, white
# VGA orders them black, blue, green, cyan, red, magenta, yellow, white
color_map = [0, 4, 2, 6, 1, 5, 3, 7]

if len(sys.argv) != 7:
	print("Usage: {sys.argv[0]} outfile infile default_fgcolor default_bgcolor origin_x origin_y", file=sys.stderr)
	sys.exit(1)

blinky_vgamode = False
if 'BUILDOPTS' in os.environ:
	for opt in os.environ['BUILDOPTS'].split():
		if opt == '-DBLINKY':
			blinky_vgamode = True
		else:
			print(f"Error: Unrecognized build option {opt}", file=sys.stderr)
			sys.exit(1)

outfile = sys.argv[1]
infile = sys.argv[2]

default_fgcolor = int(sys.argv[3])
assert 0 <= default_fgcolor <= 15
default_bgcolor = int(sys.argv[4])
assert 0 <= default_bgcolor <= 15

origin_x = int(sys.argv[5])
assert 0 <= origin_x < WIDTH
origin_y = int(sys.argv[6])
assert 0 <= origin_y < HEIGHT

chars = [bytearray([0]*HEIGHT) for _ in range(WIDTH)]
attributes = [[(Attribute(default_fgcolor, default_bgcolor, False))]*HEIGHT for _ in range(WIDTH)]

with open(infile, 'rb') as f:
	ansitext = f.read()

x = origin_x
y = origin_y
fgcolor = default_fgcolor
bgcolor = default_bgcolor
bold = False

error = False

line = 1
line_start = 0
index = 0
while index < len(ansitext):
	if ansitext[index:].startswith(b'\x1b['):
		index += len(b'\x1b[')
		escape_start = index
		while index < len(ansitext) and ansitext[index] not in b'CDHJhm':
			index += 1
		escape_params = ansitext[escape_start:index]
		escape_type = ansitext[index:index+1]
		index += 1
		if escape_type == b'C':
			x += int(escape_params)
		elif escape_type == b'D':
			x -= int(escape_params)
		elif escape_type == b'H':
			row, column = escape_params.split(b';')
			y = int(row) - 1
			x = int(column) - 1
		elif escape_type == b'J':
			# Erase display
			# We just ignore this, because why would you have
			# erase command anywhere but at the start
			pass
		elif escape_type == b'h':
			# Something nonstandard, ignore
			pass
		elif escape_type == b'm':
			for color_parameter in escape_params.split(b';'):
				color_parameter = int(color_parameter)
				if color_parameter == 0:
					bold = False
				elif color_parameter == 1:
					bold = True
				elif color_parameter == 39:
					fgcolor = default_fgcolor
				elif color_parameter == 49:
					bgcolor = default_bgcolor
				elif 30 <= color_parameter <= 37:
					fgcolor = color_map[color_parameter - 30]
				elif 40 <= color_parameter <= 47:
					bgcolor = color_map[color_parameter - 40]
				elif 90 <= color_parameter <= 97:
					fgcolor = color_map[color_parameter - 90] + 8
				elif 100 <= color_parameter <= 107:
					bgcolor = color_map[color_parameter - 100] + 8
				else:
					print(f'{line},{escape_start-line_start+1}: Unknown colour escape {color_parameter}')
					error = True
		else:
			print(f'{line},{escape_start-line_start+1}: Unknown escape ^[[{escape_params.decode()}{escape_type.decode()}')
			error = True
	elif ansitext[index] == 13:
		x = origin_x
		index += 1
	elif ansitext[index] == 10:
		for i in range(x, WIDTH):
			attributes[i][y] = Attribute(fgcolor, bgcolor, bold)
		x = origin_x
		y += 1
		index += 1
		line += 1
		line_start = index
	else:
		chars[x][y] = ansitext[index]
		attributes[x][y] = Attribute(fgcolor, bgcolor, bold)
		index += 1
		x += 1

if error:
	sys.exit(1)

with open(outfile, 'wb') as f:
	for y in range(HEIGHT):
		for x in range(WIDTH):
			fgcolor, bgcolor, bold = attributes[x][y]
			fgcolor = fgcolor | (8 if bold else 0)
			if blinky_vgamode:
				# VGA mode can be set up so that the highest
				# bit of the bg colour marks that the cell
				# should blink instead of intensity
				# Restrict the colours (including foreground
				# to account for swapping of the two) to 0…7
				fgcolor = fgcolor & 0x7
				bgcolor = bgcolor & 0x7
			char = chars[x][y]
			f.write(bytes([char, (bgcolor<<4) | fgcolor]))