#!/usr/bin/env bash

# This script checks various names for the Python interpreter for their existance and version. 
# The latest valid version is used to run the SCons build tool, which requires python2.
# This is needed because some distributions ship Pyhton3 and others Python2 their 'python'. 

function is_supported_python
{
	local exe=$1
	$exe -c 'import sys; (major, minor, a, b, c) = sys.version_info; python_version = (major, minor); exit(not (((2, 7) <= python_version) or ((3, 5) <= python_version)))' 2>/dev/null
}

declare -a supported_python_versions=(python python2.7 python2.6 python2.5 python2.4)

for exe in ${supported_python_versions[*]}; do
	if is_supported_python "$exe"; then
		exec $exe `dirname $0`/3rdParty/SCons/scons-3.0.1/script/scons.py "$@"
		exit
	fi
done

echo "No suitable Python interpreter found! Swift build system supports Python 2.7.* and Python 3.5 or higher!" >&2
exit 1