#!/bin/bash

source $(dirname "$0")/activate

PYTHON_VERSION=${PYTHON_VERSION:-}


function python() {
    # call get_python_exe only the first time it is required
    export PYTHON_EXECUTABLE=${PYTHON_EXECUTABLE:-$(python_executable)}
    "${PYTHON_EXECUTABLE}" "$@"
}


function python_executable() {
    local version=${PYTHON_VERSION}

    select_python_executables "${version}" \
        $(list_python_executables "${version}") | head -1
}


function list_python_executables() {
    PATH=${CI_TOOLS_ORIGINAL_PATH} which $(list_python_names "${version}")
}


function list_python_names() {
    local version=${1:-}
    if [ "${version}" != "" ]; then
        echo "python${version}"
    fi
    echo python3
    echo python
}


function select_python_executables() {
    local version=${1:-}
    local executable
    shift
    for executable in "$@"; do
        "${executable}" -c "${SELECT_PYTHON_EXECUTABLE_SCRIPT}" "${version}"
    done
}


read -r -d '' SELECT_PYTHON_EXECUTABLE_SCRIPT << END_OF_SCRIPT
import sys
version = ".".join(str(i) for i in sys.version_info[:3])
if version.startswith(sys.argv[1]):
    print(sys.executable)
END_OF_SCRIPT


python "$@"