import os

from tests.lib import assert_all_changes


def check_installed_version(script, package, expected):
    result = script.pip('show', package)
    lines = result.stdout.splitlines()
    version = None
    for line in lines:
        if line.startswith('Version: '):
            version = line.split()[-1]
            break
    assert version == expected, 'version {} != {}'.format(version, expected)


def check_force_reinstall(script, specifier, expected):
    """
    Args:
      specifier: the requirement specifier to force-reinstall.
      expected: the expected version after force-reinstalling.
    """
    result = script.pip_install_local('simplewheel==1.0')
    check_installed_version(script, 'simplewheel', '1.0')

    # Remove an installed file to test whether --force-reinstall fixes it.
    to_fix = script.site_packages_path.joinpath("simplewheel", "__init__.py")
    to_fix.unlink()

    result2 = script.pip_install_local('--force-reinstall', specifier)
    check_installed_version(script, 'simplewheel', expected)

    # site_packages_path is absolute, but files_created mapping uses
    # relative paths as key.
    fixed_key = os.path.relpath(to_fix, script.base_path)
    result2.did_create(fixed_key, message='force-reinstall failed')

    result3 = script.pip('uninstall', 'simplewheel', '-y')
    assert_all_changes(result, result3, [script.venv / 'build', 'cache'])


def test_force_reinstall_with_no_version_specifier(script):
    """
    Check --force-reinstall when there is no version specifier and the
    installed version is not the newest version.
    """
    check_force_reinstall(script, 'simplewheel', '2.0')


def test_force_reinstall_with_same_version_specifier(script):
    """
    Check --force-reinstall when the version specifier equals the installed
    version and the installed version is not the newest version.
    """
    check_force_reinstall(script, 'simplewheel==1.0', '1.0')