#!/usr/bin/env bash

set -ueo pipefail

die () { echo "Usage: validate-python PYTHON_EXECUTABLE"; }

test $# -eq 1 || { usage 1>&2 ; exit 2; }
python="$1"

majver=$("$python" -c 'import sys; print(sys.version_info[0])')
minver=$("$python" -c 'import sys; print(sys.version_info[1])')

# May not be correct yet, i.e. actual requirement may be higher.
if test "$majver" -gt 2 -a "$minver" -lt 3; then
    # utime follow_symlinks >= 3.3
    bup_version_str=$("$python" --version 2>&1)
    echo "ERROR: found $bup_version_str (must be >= 3.3 if >= 3)" 1>&2
    exit 2
fi