import os
import shutil
import subprocess
import sys

import pytest


def which(name):
    """Find an executable.

    Python 2.7 doesn't have shutil.which().
    shutil.which() is used, if possible, to handle Windows' case-insensitivity.
    """

    if hasattr(shutil, "which"):
        return shutil.which(name)

    for path in os.environ["PATH"].split(os.pathsep):
        if os.path.isfile(os.path.join(path, name)):
            return os.path.join(path, name)


def test_shim(root, home, dotfiles, run_dotbot):
    """Verify install shim works."""

    # Skip the test if git is unavailable.
    git = which("git")
    if git is None:
        pytest.skip("git is unavailable")

    if sys.platform[:5] == "win32":
        install = os.path.join(
            dotfiles.directory, "dotbot", "tools", "git-submodule", "install.ps1"
        )
        shim = os.path.join(dotfiles.directory, "install.ps1")
    else:
        install = os.path.join(dotfiles.directory, "dotbot", "tools", "git-submodule", "install")
        shim = os.path.join(dotfiles.directory, "install")

    # Set up the test environment.
    git_directory = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
    os.chdir(dotfiles.directory)
    subprocess.check_call([git, "init"])
    subprocess.check_call([git, "submodule", "add", git_directory, "dotbot"])
    shutil.copy(install, shim)
    dotfiles.write("foo", "pear")
    dotfiles.write_config([{"link": {"~/.foo": "foo"}}])

    # Run the shim script.
    env = dict(os.environ)
    if sys.platform[:5] == "win32":
        args = [which("powershell"), "-ExecutionPolicy", "RemoteSigned", shim]
        env["USERPROFILE"] = home
    else:
        args = [shim]
        env["HOME"] = home
    subprocess.check_call(args, env=env, cwd=dotfiles.directory)

    assert os.path.islink(os.path.join(home, ".foo"))
    with open(os.path.join(home, ".foo"), "r") as file:
        assert file.read() == "pear"