#!/bin/sh

set -eu

brute_find() {
	local op="$1" cue="$2" dir="$3"

	while true; do

		if [ $op "$dir/$cue" ]; then
			echo "$dir"
		elif [ / != "${dir:-/}" ]; then
			dir="${dir%/*}"
			continue
		fi

		return
	done
}

find_run_sh() {
	local dir="${1:-$PWD}"
	local try_repo=true
	local ws=

	while true; do

		[ "$PWD" = "$dir" ] || cd "$dir"

		# find root of repo workspace
		if $try_repo; then
			ws="$(brute_find -d .repo "$PWD")"
			[ -d "$ws" ] || try_repo=false
		fi

		# or find root of .git repository
		if [ ! -d "$ws" ]; then
			ws="$(git rev-parse --show-superproject-working-tree 2> /dev/null || true)"
			[ -d "$ws" ] || ws="$(git rev-parse --show-toplevel 2> /dev/null || true)"
		fi

		if [ ! -d "$ws" ]; then
			# no repo? find anything then
			dir="$(brute_find -x run.sh "$PWD")"
			[ -z "$dir" ] || echo "$dir/run.sh"
		elif [ -x "$ws/run.sh" ]; then
			# found at repo's root
			echo "$ws/run.sh"
		elif [ / != "${ws:-/}" ]; then
			# check on the parent's then
			dir="${ws%/*}"
			ws=
			continue
		fi

		return
	done
}

run_sh="$(find_run_sh)"

if test "x--root" = "x${1:-}"; then

	if [ -x "$run_sh" ]; then
		# found
		echo "$(dirname "$run_sh")"
		exit 0
	fi

	# failed to find workspace
	exit 1
elif [ -x "$run_sh" ]; then
	exec "$run_sh" "$@"
elif [ "$#" -gt 0 ]; then
	exec "$@"
fi