#!/usr/bin/env python3

import math
import sys
import os
import re

CP_MAX = 0x10FFFF
FONT_CPP = "data/font.cpp"
FONT_HEIGHT = 12
PTRS_PER_LINE = 8

class FontTool:
	def __init__(self):
		with open(FONT_CPP) as font_cpp:
			self.font_cpp_data = font_cpp.read()
		font_data = ([ int(s, 16) for s in re.findall(r'\w+', re.search(r'font_data[^{]*{([^;]+);', self.font_cpp_data, re.MULTILINE | re.DOTALL)[1]) ])
		font_ptrs = ([ int(s, 16) for s in re.findall(r'\w+', re.search(r'font_ptrs[^{]*{([^;]+);', self.font_cpp_data, re.MULTILINE | re.DOTALL)[1]) ])
		font_ranges = ([ int(s, 16) for s in re.findall(r'\w+', re.search(r'font_ranges[^{]*{([^;]+);', self.font_cpp_data, re.MULTILINE | re.DOTALL)[1]) ])
		self.code_points = [ False for _ in range(CP_MAX + 2) ]
		ptrs_ptr = 0
		for i in range(len(font_ranges) // 2 - 1):
			for cp in range(font_ranges[i * 2], font_ranges[i * 2 + 1] + 1):
				base = font_ptrs[ptrs_ptr]
				self.code_points[cp] = font_data[base : (base + math.ceil(font_data[base] * FONT_HEIGHT / 4) + 1)]
				ptrs_ptr += 1

	def commit(self):
		new_ranges = []
		in_range = False
		for i, data in enumerate(self.code_points):
			if in_range and not data:
				new_ranges[-1].append(i - 1)
				in_range = False
			elif not in_range and data:
				in_range = True
				new_ranges.append([ i ])
		font_data_lines_hex = [ [ '0x%02X' % v for v in d ] for d in filter(lambda x: x, self.code_points) ]
		font_data_lines = [ len(h) > 1 and h[0] + ',   ' + ', '.join(h[1 :]) + ',' or '0x00,  ' for h in font_data_lines_hex ]
		font_cpp_data = re.sub(r'font_data[^{]*{([^;]+);', 'font_data[] = {\n    ' + '\n    '.join(font_data_lines) + '\n};', self.font_cpp_data)
		font_ptrs_blocks = []
		data_ptr = 0
		for ran in new_ranges:
			block = []
			for cp in range(ran[0], ran[1] + 1):
				block.append(data_ptr)
				data_ptr += math.ceil(self.code_points[cp][0] * FONT_HEIGHT / 4) + 1
			font_ptrs_wrapped = []
			for i in range(0, len(block), PTRS_PER_LINE):
				font_ptrs_wrapped.append(', '.join([ '0x%04X' % v for v in block[i : (i + PTRS_PER_LINE)] ]))
			font_ptrs_blocks.append(',\n    '.join(font_ptrs_wrapped))
		font_cpp_data = re.sub(r'font_ptrs[^{]*{([^;]+);', 'font_ptrs[] = {\n    ' + ',\n\n    '.join(font_ptrs_blocks) + ',\n};', font_cpp_data)
		font_ranges_lines = [ '{ 0x%06X, 0x%06X },' % ( r[0], r[1] ) for r in new_ranges ]
		font_cpp_data = re.sub(r'font_ranges[^{]*{([^;]+);', 'font_ranges[][2] = {\n    ' + '\n    '.join(font_ranges_lines) + '\n    { 0, 0 },\n};', font_cpp_data)
		with open(FONT_CPP, 'w') as font_cpp:
			font_cpp.write(font_cpp_data)

	def pack(cp_matrix):
		width = 0
		for row in cp_matrix:
			if width < len(row):
				width = len(row)
		cp_data = [ width ]
		bits = 8
		for row in cp_matrix:
			padded = row + [ 0 ] * (width - len(row))
			for cv in padded:
				if bits == 8:
					cp_data.append(0)
					bits = 0
				cp_data[-1] |= (cv & 3) << bits
				bits += 2
		return cp_data

	def unpack(cp_data):
		ptr = 1
		bits = 0
		buf = 0
		cp_matrix = []
		for y in range(FONT_HEIGHT):
			cp_matrix.append([])
			for x in range(cp_data[0]):
				if bits == 0:
					buf = cp_data[ptr]
					ptr += 1
					bits = 8
				cp_matrix[-1].append(buf & 3)
				buf >>= 2
				bits -= 2
		return cp_matrix

class RawReader:
	def __init__(self, path):
		self.code_points = [ False for _ in range(CP_MAX + 2) ]
		with open(path) as raw:
			items = [ int(v) for v in re.findall(r'[0-9]+', raw.read()) ]
		ptr = 0
		while ptr <= len(items) - 2:
			cp = items[ptr]
			width = items[ptr + 1]
			ptr += 2
			matrix = []
			for i in range(ptr, ptr + width * FONT_HEIGHT, width):
				matrix.append(items[i : (i + width)])
			ptr += width * FONT_HEIGHT
			self.code_points[cp] = FontTool.pack(matrix)

class BDFReader:
	class ReadBDFError:
		def __init__(line_number, message):
			super(RuntimeError, self).__init__('line %i: %s' % ( line_number, message ))

	def __init__(self, path, xoffs, yoffs):
		self.code_points = [ False for _ in range(CP_MAX + 2) ]
		item_re = re.compile(r'[^ \n\r]+')
		with open(path) as bdf:
			global_dw = False
			startchar = False
			bitmap = False
			char_dw = False
			char_cp = False
			char_bbx = False
			skip = 0
			for line_number, line in enumerate(bdf):
				if skip:
					skip -= 1
					continue
				items = re.findall(item_re, line)
				if startchar and items[0] == 'ENDCHAR':
					if len(bitmap) != char_bbx[1]:
						raise ReadBDFError(line_number, "invalid bitmap data")
					cp_matrix = []
					for y in range(FONT_HEIGHT):
						cp_matrix.append([])
						for x in range(char_dw):
							cv = 0
							xx = x + xoffs
							yy = FONT_HEIGHT - 1 - y + yoffs
							if xx >= char_bbx[2] and xx < char_bbx[0] + char_bbx[2] and yy >= char_bbx[3] and yy < char_bbx[1] + char_bbx[3]:
								cv = bitmap[char_bbx[1] - 1 - (yy - char_bbx[3])][xx - char_bbx[2]] * 3
							cp_matrix[-1].append(cv)
					self.code_points[char_cp] = FontTool.pack(cp_matrix)
					startchar = False
					bitmap = False
					char_dw = False
					char_cp = False
					char_bbx = False
				elif bitmap != False:
					if len(items) != 1:
						raise ReadBDFError(line_number, "missing bitmap data")
					bits = []
					for ch in items[0]:
						cv = int(ch, 16)
						bits += [ cv & 8 and 1 or 0, cv & 4 and 1 or 0, cv & 2 and 1 or 0, cv & 1 and 1 or 0 ]
					bitmap.append(bits[ : char_bbx[0]])
				elif items[0] == 'SIZE':
					if len(items) != 4:
						raise ReadBDFError(line_number, "invalid directive")
				elif items[0] == 'FONTBOUNDINGBOX':
					if len(items) != 5:
						raise ReadBDFError(line_number, "invalid directive")
				elif not startchar and items[0] == 'STARTCHAR':
					startchar = True
					char_dw = global_dw
				elif items[0] == 'STARTPROPERTIES':
					if len(items) != 2:
						raise ReadBDFError(line_number, "invalid directive")
					skip = int(items[1]) + 1
				elif startchar and items[0] == 'BITMAP':
					bitmap = []
				elif startchar and items[0] == 'BBX':
					if len(items) != 5:
						raise ReadBDFError(line_number, "invalid directive")
					char_bbx = [ int(items[1]), int(items[2]), int(items[3]), int(items[4]) ]
				elif startchar and items[0] == 'ENCODING':
					if len(items) != 2:
						raise ReadBDFError(line_number, "invalid directive")
					char_cp = int(items[1])
				elif items[0] == 'METRICSSET':
					if len(items) != 2:
						raise ReadBDFError(line_number, "invalid directive")
					if int(items[1]) == 1:
						raise ReadBDFError(line_number, "font does not support writing direction 0")
				elif items[0] == 'DWIDTH':
					if len(items) != 3:
						raise ReadBDFError(line_number, "invalid directive")
					if int(items[2]) != 0:
						raise ReadBDFError(line_number, "vertical component of dwidth vector is non-zero")
					char_dw = int(items[1])
					if not startchar:
						global_dw = char_dw

if __name__ == "__main__":
	def print_usage_and_exit():
		print("""Usage:
  * fonttool.py addbdf FIRST LAST BDFFILE [XOFFS YOFFS]
  * fonttool.py addraw FIRST LAST RAWFILE
  * fonttool.py remove FIRST [LAST]
  * fonttool.py inspect FIRST [LAST]

LAST defaults to FIRST, XOFFS and YOFFS default to 0. BDF is an
archaic bitmap font format; look it up.

"Raw" files are simply ASCII-encoded white-space delimited lists
of decimal integer constants. These lists of integers encode
characters as any number of consecutive character description
structures laid out as follows:
  * the code point corresponding to the character being described;
  * the width in pixels of the character being described;
  * width times %i brightness levels between 0 and 3, a row-major matrix.

This script is also an importable module.""" % FONT_HEIGHT)
		exit(1)

	if len(sys.argv) < 3:
		print_usage_and_exit()

	cp_first = int(sys.argv[2])
	if len(sys.argv) < 4:
		cp_last = cp_first
	else:
		cp_last = int(sys.argv[3])
	if cp_first < 0 or cp_last > CP_MAX or cp_first > cp_last:
		print('invalid range')
		exit(1)

	ft = FontTool()

	if sys.argv[1] == 'addbdf':
		if len(sys.argv) < 5:
			print_usage_and_exit()
		xoffs = 0
		yoffs = 0
		if len(sys.argv) >= 6:
			xoffs = int(sys.argv[5])
		if len(sys.argv) >= 7:
			yoffs = int(sys.argv[6])
		bdfr = BDFReader(sys.argv[4], xoffs, yoffs)
		for i in range(cp_first, cp_last + 1):
			if bdfr.code_points[i] and not ft.code_points[i]:
				ft.code_points[i] = bdfr.code_points[i]
		ft.commit()
	elif sys.argv[1] == 'addraw':
		if len(sys.argv) < 5:
			print_usage_and_exit()
		rr = RawReader(sys.argv[4])
		for i in range(cp_first, cp_last + 1):
			if rr.code_points[i] and not ft.code_points[i]:
				ft.code_points[i] = rr.code_points[i]
		ft.commit()
	elif sys.argv[1] == 'remove':
		for i in range(cp_first, cp_last + 1):
			ft.code_points[i] = False
		ft.commit()
	elif sys.argv[1] == 'inspect':
		lut = [ '  ', '░░', '▒▒', '▓▓' ]
		for i in range(cp_first, cp_last + 1):
			if ft.code_points[i]:
				print('code point %i (%c)' % ( i, i ))
				print('')
				print('\n'.join([ ''.join([ lut[ch] for ch in row ]) for row in FontTool.unpack(ft.code_points[i]) ]))
				print('')
			else:
				print('code point %i (%c) is not available' % ( i, i ))
	else:
		print_usage_and_exit()