#!/usr/bin/python

import sys

import os.path

if len (sys.argv) != 4:

	print >>sys.stderr, "usage: ./gen-arabic-table.py ArabicShaping.txt UnicodeData.txt Blocks.txt"

	sys.exit (1)

files = [file (x) for x in sys.argv[1:]]

headers = [[files[0].readline (), files[0].readline ()], [files[2].readline (), files[2].readline ()]]

headers.append (["UnicodeData.txt does not have a header."])

while files[0].readline ().find ('##################') < 0:

	pass

blocks = {}

def read_blocks(f):

	global blocks

	for line in f:

		j = line.find ('#')

		if j >= 0:

			line = line[:j]

		fields = [x.strip () for x in line.split (';')]

		if len (fields) == 1:

			continue

		uu = fields[0].split ('..')

		start = int (uu[0], 16)

		if len (uu) == 1:

			end = start

		else:

			end = int (uu[1], 16)

		t = fields[1]

		for u in range (start, end + 1):

			blocks[u] = t

def print_joining_table(f):

	values = {}

	for line in f:

		if line[0] == '#':

			continue

		fields = [x.strip () for x in line.split (';')]

		if len (fields) == 1:

			continue

		u = int (fields[0], 16)

		if fields[3] in ["ALAPH", "DALATH RISH"]:

			value = "JOINING_GROUP_" + fields[3].replace(' ', '_')

		else:

			value = "JOINING_TYPE_" + fields[2]

		values[u] = value

	short_value = {}

	for value in set([v for v in values.values()] + ['JOINING_TYPE_X']):

		short = ''.join(x[0] for x in value.split('_')[2:])

		assert short not in short_value.values()

		short_value[value] = short

	print

	for value,short in short_value.items():

		print "#define %s	%s" % (short, value)

	uu = sorted(values.keys())

	num = len(values)

	all_blocks = set([blocks[u] for u in uu])

	last = -100000

	ranges = []

	for u in uu:

		if u - last <= 1+16*5:

			ranges[-1][-1] = u

		else:

			ranges.append([u,u])

		last = u

	print

	print "static const uint8_t joining_table[] ="

	print "{"

	last_block = None

	offset = 0

	for start,end in ranges:

		print

		print "#define joining_offset_0x%04xu %d" % (start, offset)

		for u in range(start, end+1):

			block = blocks.get(u, last_block)

			value = values.get(u, "JOINING_TYPE_X")

			if block != last_block or u == start:

				if u != start:

					print

				if block in all_blocks:

					print "\n  /* %s */" % block

				else:

					print "\n  /* FILLER */"

				last_block = block

				if u % 32 != 0:

					print

					print "  /* %04X */" % (u//32*32), "  " * (u % 32),

			if u % 32 == 0:

				print

				print "  /* %04X */ " % u,

			sys.stdout.write("%s," % short_value[value])

		print

		offset += end - start + 1

	print

	occupancy = num * 100. / offset

	print "}; /* Table items: %d; occupancy: %d%% */" % (offset, occupancy)

	print

	page_bits = 12;

	print

	print "static unsigned int"

	print "joining_type (hb_codepoint_t u)"

	print "{"

	print "  switch (u >> %d)" % page_bits

	print "  {"

	pages = set([u>>page_bits for u in [s for s,e in ranges]+[e for s,e in ranges]])

	for p in sorted(pages):

		print "    case 0x%0Xu:" % p

		for (start,end) in ranges:

			if p not in [start>>page_bits, end>>page_bits]: continue

			offset = "joining_offset_0x%04xu" % start

			print "      if (hb_in_range<hb_codepoint_t> (u, 0x%04Xu, 0x%04Xu)) return joining_table[u - 0x%04Xu + %s];" % (start, end, start, offset)

		print "      break;"

		print ""

	print "    default:"

	print "      break;"

	print "  }"

	print "  return X;"

	print "}"

	print

	for value,short in short_value.items():

		print "#undef %s" % (short)

	print

def print_shaping_table(f):

	shapes = {}

	ligatures = {}

	names = {}

	for line in f:

		fields = [x.strip () for x in line.split (';')]

		if fields[5][0:1] != '<':

			continue

		items = fields[5].split (' ')

		shape, items = items[0][1:-1], tuple (int (x, 16) for x in items[1:])

		if not shape in ['initial', 'medial', 'isolated', 'final']:

			continue

		c = int (fields[0], 16)

		if len (items) != 1:

			# We only care about lam-alef ligatures

			if len (items) != 2 or items[0] != 0x0644 or items[1] not in [0x0622, 0x0623, 0x0625, 0x0627]:

				continue

			# Save ligature

			names[c] = fields[1]

			if items not in ligatures:

				ligatures[items] = {}

			ligatures[items][shape] = c

			pass

		else:

			# Save shape

			if items[0] not in names:

				names[items[0]] = fields[1]

			else:

				names[items[0]] = os.path.commonprefix ([names[items[0]], fields[1]]).strip ()

			if items[0] not in shapes:

				shapes[items[0]] = {}

			shapes[items[0]][shape] = c

	print

	print "static const uint16_t shaping_table[][4] ="

	print "{"

	keys = shapes.keys ()

	min_u, max_u = min (keys), max (keys)

	for u in range (min_u, max_u + 1):

		s = [shapes[u][shape] if u in shapes and shape in shapes[u] else 0

		     for shape in  ['initial', 'medial', 'final', 'isolated']]

		value = ', '.join ("0x%04Xu" % c for c in s)

		print "  {%s}, /* U+%04X %s */" % (value, u, names[u] if u in names else "")

	print "};"

	print

	print "#define SHAPING_TABLE_FIRST	0x%04Xu" % min_u

	print "#define SHAPING_TABLE_LAST	0x%04Xu" % max_u

	print

	ligas = {}

	for pair in ligatures.keys ():

		for shape in ligatures[pair]:

			c = ligatures[pair][shape]

			if shape == 'isolated':

				liga = (shapes[pair[0]]['initial'], shapes[pair[1]]['final'])

			elif shape == 'final':

				liga = (shapes[pair[0]]['medial'], shapes[pair[1]]['final'])

			else:

				raise Exception ("Unexpected shape", shape)

			if liga[0] not in ligas:

				ligas[liga[0]] = []

			ligas[liga[0]].append ((liga[1], c))

	max_i = max (len (ligas[l]) for l in ligas)

	print

	print "static const struct ligature_set_t {"

	print " uint16_t first;"

	print " struct ligature_pairs_t {"

	print "   uint16_t second;"

	print "   uint16_t ligature;"

	print " } ligatures[%d];" % max_i

	print "} ligature_table[] ="

	print "{"

	keys = ligas.keys ()

	keys.sort ()

	for first in keys:

		print "  { 0x%04Xu, {" % (first)

		for liga in ligas[first]:

			print "    { 0x%04Xu, 0x%04Xu }, /* %s */" % (liga[0], liga[1], names[liga[1]])

		print "  }},"

	print "};"

	print

print "/* == Start of generated table == */"

print "/*"

print " * The following table is generated by running:"

print " *"

print " *   ./gen-arabic-table.py ArabicShaping.txt UnicodeData.txt Blocks.txt"

print " *"

print " * on files with these headers:"

print " *"

for h in headers:

	for l in h:

		print " * %s" % (l.strip())

print " */"

print

print "#ifndef HB_OT_SHAPE_COMPLEX_ARABIC_TABLE_HH"

print "#define HB_OT_SHAPE_COMPLEX_ARABIC_TABLE_HH"

print

read_blocks (files[2])

print_joining_table (files[0])

print_shaping_table (files[1])

print

print "#endif /* HB_OT_SHAPE_COMPLEX_ARABIC_TABLE_HH */"

print

print "/* == End of generated table == */"