#!/usr/bin/env bash

# somewhat portable way to detect CPU count
detect_cpu_count () {
    if [ "$CPUS" = "" ]; then
        # Windows standard environment variable
        CPUS="$NUMBER_OF_PROCESSORS"
    fi
    if [ "$CPUS" = "" ]; then
        # Linux
        CPUS=`getconf _NPROCESSORS_ONLN 2>/dev/null`
    fi
    if [ "$CPUS" = "" ]; then
        # FreeBSD
        CPUS=`getconf NPROCESSORS_ONLN 2>/dev/null`
    fi
    if [ "$CPUS" = "" ]; then
        # nothing helped
        CPUS="1"
    fi
}

lc_run() {
    LANG=C LC_ALL=C "$@"
}

valgrind=""
skeleton=0
keep_tmp_files=0
wine=""
re2c="./re2c"
threads=`detect_cpu_count; echo $CPUS`
tests=()
for arg in $*
do
	case $arg in
		"--valgrind" ) valgrind=`which valgrind` ;;
		"--skeleton" ) skeleton=1 ;;
		"--keep-tmp-files" ) keep_tmp_files=1 ;;
		"--wine" )
			wine=`which wine`
			re2c="${re2c}.exe"
			;;
		"-j"* )
			number=${arg#-j}
			number_pattern='^[0-9]+$'
			if [[ $number =~ $number_pattern ]]
			then
				threads=$number
			fi
			;;
		* ) tests+=("$arg") ;;
	esac
done
echo "Running in ${threads} thread(s)"

test_srcdir=""
if [ ${#tests[@]} -eq 0 ]
then
    test_srcdir="@top_srcdir@/test"
    tests=(`find $test_srcdir -name '*.re' | sort`)
fi
test_blddir="test_"`date +%y%m%d%H%M%S`
rm -rf $test_blddir && mkdir $test_blddir

tests_per_thread=$((${#tests[@]} / threads + 1))
packs=()
for ((i = 0; i < threads; i++))
do
	j=$((i * tests_per_thread))
	packs[$i]=${tests[@]:j:tests_per_thread}
done

if test ! -x "${re2c}"
then
	echo "Cannot find re2c executable (${re2c})."
	exit 1
fi

if test -n "${valgrind}"
then
	valgrind_options=(
		"-q"
		"--track-origins=yes"
		"--num-callers=50"
		"--leak-check=full"
		"--show-reachable=yes"
		"--malloc-fill=0xa1"
		"--free-fill=0xa1"
		)
	valgrind="${valgrind} ${valgrind_options[@]}"
	echo $valgrind
fi

diff_prog="diff"
if test -n "${wine}"
then
	# ignore whitespace at the end of line
	diff_prog="${diff_prog} -b"
fi

run_pack() {
	local log="$1"
	shift 1

	local errcnt=0
	for x in $*
	do
		cd $test_blddir

		# preserve directory structure unless given explicit args
		if [ -z "$test_srcdir" ]
		then
			local outx=`basename $x`
		else
			# remove prefix
			local outx=${x:$((${#test_srcdir} + 1))}
			mkdir -p `dirname $outx`
		fi
		local outc="${outx%.re}.c"

		# filename (dot short* (long arg?)*)? ext
		# must keep to POSIX standard: no syntactic sugar like +,?, etc.
		# if you change this regexp, try it with 'sed --posix'
		local switches=`basename "$x" | lc_run sed \
			-e 's/^[^.]*\.re$//g' \
			-e 's/^[^.]*\.\(.*\)\.re$/\1/g' \
			-e 's/^\([^-]\)/-\1/' \
			-e 's/--\([^ (-]*\)/ --\1/g' \
			-e 's/(\([^)]*\))/ \1/g'`
		# check that flags do not contain uppercase letters:
		# file extensions are case-insensitive on some platforms
		printf "%s" "$switches" | lc_run grep -q "[A-Z]" \
			&& { echo "bad file extension: '$outx' (uppercase letters are not allowed)"; exit 1; }
		local switches="$switches -o $outc --no-version --no-generation-date"
		# enable warnings globally
		local switches="$switches -W"

		if [ $skeleton -eq 1 ]
		then
			local switches="$switches --skeleton -Werror-undefined-control-flow"

			local status=0
			${valgrind} ${wine} ../${re2c} $switches "../$x" 2>"$outc.stderr" || status=1
			[ $status -eq 0 ] && { @CC@ -Wall -Wextra -o "$outc.out" "$outc" 2>>"$outc.stderr" || status=2; }
			[ $status -eq 0 ] && { ./"$outc.out" 2>>"$outc.stderr" || status=3; }

			case $status in
				0 ) local msg="OK" ;;
				1 ) local msg="OK (expected re2c error)" ;;
				2 ) local msg="FAIL (compilation error)" ;;
				3 ) local msg="FAIL (runtime error)" ;;
			esac
			printf "%-25s $outx\n" "$msg"

			if [ $status -le 1 ]; then
				[ $keep_tmp_files -eq 0 ] && rm -f "$outc"{,.line*.{input,keys},.stderr,.out}
			else
				cp -f "../$x" "$outx"
				local errcnt=$(($errcnt + 1))
			fi
		else
			# create sandbox
			tmpdir="tmp_$log" \
				&& mkdir "$tmpdir" \
				&& cd "$tmpdir" \
				&& mkdir -p `dirname "$outx"` \
				&& cp "../../$x" "$outx"
			# run re2c
			$valgrind $wine ../../$re2c $switches "$outx" 2>"$outc.stderr" 1>&2
			# paste all files dropped by re2c into output file
			rm "$outx" && find . -type f \
				| lc_run sort \
				| xargs cat \
				>> "../$outc"
			# cleanup sandbox
			cd .. \
				&& rm -rf "$tmpdir"

			# compare results
			local c="${x%.re}.c"
			local status=""
			[ -z $status ] && status=`[ -f "../$c" ] || echo "MISSING"`
			[ -z $status ] && status=`$diff_prog "../$c" "$outc" > "$outc.diff" || echo "FAIL"`
			[ -z $status ] && status="OK"
			if [ $status = "OK" ]
			then
				rm "$outc" "$outc.diff"
			else
				cp -f "../$x" "$outx"
				cp -f "../$c" "$outc.orig"
				local errcnt=$(($errcnt + 1))
			fi

			printf "%-10s $outx\n" "$status"
		fi
		cd ..
	done
	echo $errcnt > $log
}

cleanup() {
	rm -f ${logs[@]}
	kill ${wait_pids[@]}
	wait ${wait_pids[@]}
	printf "\nEh...\n"
	exit 1
}

logs=()
wait_pids=()
trap cleanup INT
for ((i = 0; i < ${#packs[@]}; i++))
do
	logs[$i]=`date +%y%m%d%H%M%S`_$i
	run_pack ${logs[i]} ${packs[i]} &
	wait_pids+=( $! )
done
wait ${wait_pids[@]}

errors=0
for ((i = 0; i < ${#logs[@]}; i++))
do
	error=`cat ${logs[i]}`
	errors=$((errors + error))
	rm -f ${logs[i]}
done

# remove empty directories
for d in `find $test_blddir -depth -type d`
do
	entries=`ls -A "$d"`
	if [ -z "$entries" ]
	then
		rmdir "$d"
	fi
done

if [ $errors -eq 0 ]
then
	echo "All ${#tests[@]} tests passed successfully."
	exit 0
else
	echo "Error: $errors out ${#tests[@]} tests failed."
	exit 1
fi