from contextlib import contextmanager
import os
import subprocess
from tempfile import TemporaryDirectory
from repo2docker.contentproviders import Git


@contextmanager
def git_repo():
    """
    Makes a dummy git repo in which user can perform git operations

    Should be used as a contextmanager, it will delete directory when done
    """

    with TemporaryDirectory() as gitdir:
        subprocess.check_call(['git', 'init'], cwd=gitdir)
        yield gitdir


def test_clone():
    """Test simple git clone to a target dir"""
    with git_repo() as upstream:
        with open(os.path.join(upstream, 'test'), 'w') as f:
            f.write("Hello")

        subprocess.check_call(['git', 'add', 'test'], cwd=upstream)
        subprocess.check_call(['git', 'commit', '-m', 'Test commit'],
                              cwd=upstream)

        with TemporaryDirectory() as clone_dir:
            spec = {'repo': upstream}
            for _ in Git().fetch(spec, clone_dir):
                pass
            assert os.path.exists(os.path.join(clone_dir, 'test'))


def test_always_accept():
    # The git content provider should always accept a spec
    assert Git().detect('/tmp/doesnt-exist', ref='1234')
    assert Git().detect('/tmp/doesnt-exist')
    # a path that exists
    assert Git().detect('/etc', ref='1234')
    # a remote URL
    assert Git().detect('https://example.com/path/here')