#!/usr/bin/env python

"""
Rebuilds the .travis.yml file based on the output of ``tox --listenvs``
"""

import subprocess as sp

template = """\
# !!! WARNING !!!
# This file is automatically generated by ./rebuild-travis-yaml
# !!! WARNING !!!
language: python
sudo: false
matrix:
  include:
{env_list}
install: pip install tox==3.7.0
script: tox
# !!! WARNING !!!
# This file is automatically generated by ./rebuild-travis-yaml
# !!! WARNING !!!
"""

# Maps tox python versions (ex, "py27") to Travis Python versions (ex, "2.7")
py_version_map = {
    "py26": "2.6",
    "py27": "2.7",
    "py35": "3.5",
    "py36": "3.6",
    "py37": "3.7",
    "pypy": "pypy",
}

def main():
    tox_envs = sp.check_output("tox --listenvs", shell=True).splitlines()
    env_list = []
    for env in tox_envs:
        if not env.strip():
            continue
        py_ver, _, _ = env.partition("-")
        env_list.append("""\
    - env: "TOXENV=%s"
      python: "%s"
""" %(env, py_version_map[py_ver]))

    with open(".travis.yml", "w") as f:
        f.write(template.format(env_list="".join(env_list)))


if __name__ == "__main__":
    main()