#!/bin/sh

case "$1" in
	--help)
		echo "usage: $0 [--config file] [other_git_tree...] [--] [test_scripts]"
		exit 0
		;;
	--config)
		shift
		GIT_PERF_CONFIG_FILE=$(cd "$(dirname "$1")"; pwd)/$(basename "$1")
		export GIT_PERF_CONFIG_FILE
		shift ;;
esac

die () {
	echo >&2 "error: $*"
	exit 1
}

run_one_dir () {
	if test $# -eq 0; then
		set -- p????-*.sh
	fi
	echo "=== Running $# tests in ${GIT_TEST_INSTALLED:-this tree} ==="
	for t in "$@"; do
		./$t $GIT_TEST_OPTS
	done
}

unpack_git_rev () {
	rev=$1
	echo "=== Unpacking $rev in build/$rev ==="
	mkdir -p build/$rev
	(cd "$(git rev-parse --show-cdup)" && git archive --format=tar $rev) |
	(cd build/$rev && tar x)
}

build_git_rev () {
	rev=$1
	for config in config.mak config.mak.autogen config.status
	do
		if test -e "../../$config"
		then
			cp "../../$config" "build/$rev/"
		fi
	done
	echo "=== Building $rev ==="
	(
		cd build/$rev &&
		if test -n "$GIT_PERF_MAKE_COMMAND"
		then
			sh -c "$GIT_PERF_MAKE_COMMAND"
		else
			make $GIT_PERF_MAKE_OPTS
		fi
	) || die "failed to build revision '$mydir'"
}

run_dirs_helper () {
	mydir=${1%/}
	shift
	while test $# -gt 0 -a "$1" != -- -a ! -f "$1"; do
		shift
	done
	if test $# -gt 0 -a "$1" = --; then
		shift
	fi
	if [ ! -d "$mydir" ]; then
		rev=$(git rev-parse --verify "$mydir" 2>/dev/null) ||
		die "'$mydir' is neither a directory nor a valid revision"
		if [ ! -d build/$rev ]; then
			unpack_git_rev $rev
		fi
		build_git_rev $rev
		mydir=build/$rev
	fi
	if test "$mydir" = .; then
		unset GIT_TEST_INSTALLED
	else
		GIT_TEST_INSTALLED="$mydir/bin-wrappers"
		# Older versions of git lacked bin-wrappers; fallback to the
		# files in the root.
		test -d "$GIT_TEST_INSTALLED" || GIT_TEST_INSTALLED=$mydir
		export GIT_TEST_INSTALLED
	fi
	run_one_dir "$@"
}

run_dirs () {
	while test $# -gt 0 -a "$1" != -- -a ! -f "$1"; do
		run_dirs_helper "$@"
		shift
	done
}

get_subsections () {
	section="$1"
	test -z "$GIT_PERF_CONFIG_FILE" && return
	git config -f "$GIT_PERF_CONFIG_FILE" --name-only --get-regex "$section\..*\.[^.]+" |
	sed -e "s/$section\.\(.*\)\..*/\1/" | sort | uniq
}

get_var_from_env_or_config () {
	env_var="$1"
	conf_sec="$2"
	conf_var="$3"
	# $4 can be set to a default value

	# Do nothing if the env variable is already set
	eval "test -z \"\${$env_var+x}\"" || return

	test -z "$GIT_PERF_CONFIG_FILE" && return

	# Check if the variable is in the config file
	if test -n "$GIT_PERF_SUBSECTION"
	then
		var="$conf_sec.$GIT_PERF_SUBSECTION.$conf_var"
		conf_value=$(git config -f "$GIT_PERF_CONFIG_FILE" "$var") &&
		eval "$env_var=\"$conf_value\"" && return
	fi
	var="$conf_sec.$conf_var"
	conf_value=$(git config -f "$GIT_PERF_CONFIG_FILE" "$var") &&
	eval "$env_var=\"$conf_value\"" && return

	test -n "${4+x}" && eval "$env_var=\"$4\""
}

run_subsection () {
	get_var_from_env_or_config "GIT_PERF_REPEAT_COUNT" "perf" "repeatCount" 3
	export GIT_PERF_REPEAT_COUNT

	get_var_from_env_or_config "GIT_PERF_DIRS_OR_REVS" "perf" "dirsOrRevs"
	set -- $GIT_PERF_DIRS_OR_REVS "$@"

	get_var_from_env_or_config "GIT_PERF_MAKE_COMMAND" "perf" "makeCommand"
	get_var_from_env_or_config "GIT_PERF_MAKE_OPTS" "perf" "makeOpts"

	GIT_PERF_AGGREGATING_LATER=t
	export GIT_PERF_AGGREGATING_LATER

	if test $# = 0 -o "$1" = -- -o -f "$1"; then
		set -- . "$@"
	fi

	run_dirs "$@"
	./aggregate.perl "$@"
}

cd "$(dirname $0)"
. ../../GIT-BUILD-OPTIONS

mkdir -p test-results
get_subsections "perf" >test-results/run_subsections.names

if test $(wc -l <test-results/run_subsections.names) -eq 0
then
	(
		run_subsection "$@"
	)
else
	while read -r subsec
	do
		(
			GIT_PERF_SUBSECTION="$subsec"
			export GIT_PERF_SUBSECTION
			echo "======== Run for subsection '$GIT_PERF_SUBSECTION' ========"
			run_subsection "$@"
		)
	done <test-results/run_subsections.names
fi