# Generate the dense EUC-KR/UHC lookup arrays used by lib/ksc5601.c
#
# Usage:
#   hawk -f tools/gen-ksc5601-tabs.hawk -- tools/KSC5601.TXT
#   hawk -f tools/gen-ksc5601-tabs.hawk -- --forward tools/KSC5601.TXT
#   hawk -f tools/gen-ksc5601-tabs.hawk -- --reverse tools/KSC5601.TXT
#

BEGIN {
	MODE = "all";
	bad = 0;

	init_forward_pages();
	init_reverse_pages();
	parse_args();
}

/^[ \t]*0x[0-9A-Fa-f]+/ {
	@local ks, uc;

	ks = parse_hex($1);
	uc = parse_hex($2);

	if (ks < 0 || uc < 0) next;

	add_forward_mapping(ks, uc);
	add_reverse_mapping(ks, uc);
}

END {
	@local i, first;

	install_ctype_euc_kr_overrides();
	if (bad) exit 1;

	printf("/* generated by tools/gen-ksc5601-tabs.hawk from %s */\n\n", input_name());

	first = 1;

	if (MODE == "all" || MODE == "forward")
	{
		for (i = 1; i <= fwd_page_count; i++)
		{
			if (!first) printf("\n");
			dump_forward_page(i);
			first = 0;
		}
	}

	if (MODE == "all" || MODE == "reverse")
	{
		for (i = 1; i <= rev_page_count; i++)
		{
			if (!first) printf("\n");
			dump_reverse_page(i);
			first = 0;
		}
	}
}

function parse_args()
{
	@local i, a;

	for (i = 1; i < ARGC; i++)
	{
		a = ARGV[i];
		if (a == "" || substr(a, 1, 2) != "--") continue;

		if (a == "--all")
			MODE = "all";
		else if (a == "--forward")
			MODE = "forward";
		else if (a == "--reverse")
			MODE = "reverse";
		else
		{
			printf("unknown option %s\n", a) > "/dev/stderr";
			bad = 1;
		}

		ARGV[i] = "";
	}
}

function input_name()
{
	@local i, sep, out;

	sep = "";
	out = "";

	for (i = 1; i < ARGC; i++)
	{
		if (ARGV[i] == "") continue;
		out = out sep ARGV[i];
		sep = ", ";
	}

	return (out != "")? out: "<stdin>";
}

function hex_digit(ch)
{
	if (ch >= "0" && ch <= "9") return ch + 0;
	if (ch >= "A" && ch <= "F") return 10 + index("ABCDEF", ch) - 1;
	if (ch >= "a" && ch <= "f") return 10 + index("abcdef", ch) - 1;
	return -1;
}

function parse_hex(s)
{
	@local i, n, d;
	n = 0;

	if (substr(s, 1, 2) == "0x" || substr(s, 1, 2) == "0X")
		s = substr(s, 3);

	for (i = 1; i <= length(s); i++)
	{
		d = hex_digit(substr(s, i, 1));
		if (d < 0) return -1;
		n = n * 16 + d;
	}

	return n;
}

function init_forward_pages()
{
	fwd_page_count = 2;
	fwd_page_no = @[0, 1];
	fwd_name    = @["ksc_to_uc_0", "ksc_to_uc_1"];
	fwd_from    = @[0x8141, 0xcaa1];
	fwd_to      = @[0xc8fe, 0xfdfe];
	fwd_len     = @[fwd_to[1] - fwd_from[1] + 1, fwd_to[2] - fwd_from[2] + 1];
	fwd_data    = @[];
}

function init_reverse_pages()
{
	rev_page_count = 11;

	rev_page_no[1] = 0;
	rev_name[1] = "uc_to_ksc_0";
	rev_from[1] = 0x00A1;
	rev_to[1] = 0x0167;

	rev_page_no[2] = 1;
	rev_name[2] = "uc_to_ksc_1";
	rev_from[2] = 0x02C7;
	rev_to[2] = 0x0451;

	rev_page_no[3] = 2;
	rev_name[3] = "uc_to_ksc_2";
	rev_from[3] = 0x2015;
	rev_to[3] = 0x2312;

	rev_page_no[4] = 3;
	rev_name[4] = "uc_to_ksc_3";
	rev_from[4] = 0x2460;
	rev_to[4] = 0x266D;

	rev_page_no[5] = 4;
	rev_name[5] = "uc_to_ksc_4";
	rev_from[5] = 0x3000;
	rev_to[5] = 0x327F;

	rev_page_no[6] = 5;
	rev_name[6] = "uc_to_ksc_5";
	rev_from[6] = 0x3380;
	rev_to[6] = 0x33DD;

	rev_page_no[7] = 6;
	rev_name[7] = "uc_to_ksc_6";
	rev_from[7] = 0x4E00;
	rev_to[7] = 0x947F;

	rev_page_no[8] = 7;
	rev_name[8] = "uc_to_ksc_7";
	rev_from[8] = 0x9577;
	rev_to[8] = 0x9F9C;

	rev_page_no[9] = 8;
	rev_name[9] = "uc_to_ksc_8";
	rev_from[9] = 0xAC00;
	rev_to[9] = 0xD7A3;

	rev_page_no[10] = 9;
	rev_name[10] = "uc_to_ksc_9";
	rev_from[10] = 0xF900;
	rev_to[10] = 0xFA0B;

	rev_page_no[11] = 10;
	rev_name[11] = "uc_to_ksc_10";
	rev_from[11] = 0xFF01;
	rev_to[11] = 0xFFE6;

	for (i = 1; i <= rev_page_count; i++)
		rev_len[i] = rev_to[i] - rev_from[i] + 1;
}

function add_forward_mapping(ks, uc)
{
	@local i, idx, old;

	for (i = 1; i <= fwd_page_count; i++)
	{
		if (ks < fwd_from[i] || ks > fwd_to[i]) continue;

		idx = ks - fwd_from[i];
		old = fwd_data[i][idx] + 0;
		if (old != 0 && old != uc)
		{
			printf("duplicate forward mapping for 0x%04x: 0x%04x vs 0x%04x\n", ks, old, uc) > "/dev/stderr";
			bad = 1;
			return;
		}

		fwd_data[i][idx] = uc;
		return;
	}
}

function add_reverse_mapping(ks, uc)
{
	@local i, idx, old;
	for (i = 1; i <= rev_page_count; i++)
	{
		if (uc < rev_from[i] || uc > rev_to[i]) continue;

		idx = uc - rev_from[i];
		old = rev_data[i][idx] + 0;
		if (old != 0 && old != ks)
		{
			printf("duplicate reverse mapping for U+%04x: 0x%04x vs 0x%04x\n", uc, old, ks) > "/dev/stderr";
			bad = 1;
			return;
		}

		rev_data[i][idx] = ks;
		return;
	}
}

function install_ctype_euc_kr_overrides()
{
	## some characters not found in the obsolete KSC5601.TXT file

	## euro sign
	add_forward_mapping(0xA2E6, 0x20AC);
	add_reverse_mapping(0xA2E6, 0x20AC);

	## registered trademark sign
	add_forward_mapping(0xA2E7, 0x00AE);
	add_reverse_mapping(0xA2E7, 0x00AE);

	# circled korean postal code sign
	add_forward_mapping(0xA2E8, 0x327E);
	add_reverse_mapping(0xA2E8, 0x327E);
}

function dump_dense_array(kind, page, total)
{
	@local i, v;
	for (i = 0; i < total; i++)
	{
		if ((i % 9) == 0) printf("\t");

		if (kind == "forward")
			v = fwd_data[page][i] + 0;
		else
			v = rev_data[page][i] + 0;

		printf("0x%04x", v);
		if (i + 1 < total) printf(", ");

		if ((i % 9) == 8 || i + 1 >= total)
			printf("\n");
	}
}

function dump_forward_page(i)
{
	printf("/* page %d 0x%04x-0x%04x */\n", fwd_page_no[i], fwd_from[i], fwd_to[i]);
	printf("static const hawk_uint16_t %s[] = {\n", fwd_name[i]);
	dump_dense_array("forward", i, fwd_len[i]);
	printf("};\n");
}

function dump_reverse_page(i)
{
	printf("/* page %d 0x%04x-0x%04x */\n", rev_page_no[i], rev_from[i], rev_to[i]);
	printf("static const hawk_uint16_t %s[] = {\n", rev_name[i]);
	dump_dense_array("reverse", i, rev_len[i]);
	printf("};\n");
}