#!/bin/sh

echo
echo Generating code page translation tables.

codepages=`cat index.txt`

if [ -n "$codepages" ]; then

(

n=0

echo '/* Automatically generated by gen-cp */'
echo '/* DO NOT EDIT THIS FILE! EDIT Unicode/<whatever> INSTEAD! */'
echo '/* See the input files for copyrights and licences. */'
echo

for i in $codepages; do
	echo -n $i' ' 1>&2
	echo

	echo
	echo "/*** $i ***/"
	echo

	sed '	# Delete the name and aliases lines.
		1,2d
		# Delete comment-only and blank lines.
		/^[	 ]*\(#.*\)\{,1\}$/d
		# Copy to the hold space.
		h
		# Delete everything except the comment.
		s/^[^#]*//
		# If there is a comment, change it to use /* */ delimiters.
		s!#[	 ]*\(.*\)!/* \1 */!
		# Exchange spaces; now hold space = comment and pattern space = all.
		x
		# Delete the comment. 
		s/#.*//
		# Canonicalize case so the strings can be used as lookup keys.
		y/Xabcdef/xABCDEF/
		# Delete mappings of bytes 0x00...0x7F.  ELinks assumes those match ASCII. 
		/^0x[01234567]/d
		# Delete lines that do not map the byte to exactly one character.
		/^[ 	]*0x[0123456789ABCDEF]\{2\}[ 	]\{1,\}0x[0123456789ABCDEF]\{1,\}[ 	]*$/!d
		# Append a newline and the comment from the hold space.
		G
		# Delete the newline added by the previous command.
		s/\n//' "$i.cp" | {
		for left in 8 9 A B C D E F; do
			for right in 0 1 2 3 4 5 6 7 8 9 A B C D E F; do
				eval "high0x$left$right="
			done
		done
		table=
		highuse=
	    	while read byte unicode comment; do
			if eval "[ \"\$high$byte\" ]"; then
				table="$table	{$byte, $unicode},${comment+ }$comment
"
			else
				eval "high$byte=\"\$unicode,\${comment+ }\$comment\""
				highuse=1
			fi
		done
		if [ "$highuse" ]; then
			printf "const uint16_t highhalf_%s [] = {\n" "$i"
			for left in 8 9 A B C D E F; do
				for right in 0 1 2 3 4 5 6 7 8 9 A B C D E F; do
					eval "printf \"\\t/* %s */ %s\\n\" \"0x$left$right\" \"\${high0x$left$right:-0xFFFF,}\""
				done
			done
			printf "};\n\n"
		else
			printf "#define highhalf_%s highhalf_NULL\n\n" "$i"
		fi
		if [ "$table" ]; then
			printf "const struct table_entry table_%s [] = {\n%s\t{0, 0}\n};\n" "$i" "$table"
		else
			printf "#define table_%s table_NULL\n" "$i"
		fi
		printf "\n"
	}

	echo 'unsigned char *const aliases_'$i' [] = {'
	head -n 2 $i.cp | tail -n +2 | sed 's/ \+/ /g; s/ $//; s/\", /\",£/g; s/$/,/' | tr "£" "\n" \
	| sed 's/^/£/g' | tr "£" "\t" 
	echo '	NULL
};'
	n=`expr $n + 1`
done

printf "\n/*** NULL ***/\n\n"
printf "const uint16_t highhalf_NULL [] = {\n"
for r in `seq 16`; do
	printf "\t0xFFFF,0xFFFF,0xFFFF,0xFFFF, 0xFFFF,0xFFFF,0xFFFF,0xFFFF,\n"
done
printf "};\n\n"
printf "const struct table_entry table_NULL [] = {\n"
printf "\t{0, 0}\n"
printf "};\n"

echo
echo 'const struct codepage_desc codepages [] = {'

for i in $codepages; do
	echo '	{"'`head -n 1 $i.cp`'", aliases_'$i', highhalf_'$i', table_'$i'},'
done

echo '	{NULL, NULL, NULL}'
echo '};'

echo
echo '#define N_CODEPAGES '$n | sed 's/
//g'

) | sed 's/
//g' > ../src/intl/codepage.inc

echo
echo Done.

fi

echo
