import os

from pipenv import environments, exceptions
from pipenv.patched.pip._vendor import rich
from pipenv.utils.requirements import import_requirements
from pipenv.vendor import click

console = rich.console.Console()
err = rich.console.Console(stderr=True)


def walk_up(bottom):
    """mimic os.walk, but walk 'up' instead of down the directory tree.
    From: https://gist.github.com/zdavkeos/1098474
    """

    bottom = os.path.realpath(bottom)

    # get files in current dir
    try:
        names = os.listdir(bottom)
    except Exception:
        return

    dirs, nondirs = [], []
    for name in names:
        if os.path.isdir(os.path.join(bottom, name)):
            dirs.append(name)
        else:
            nondirs.append(name)

    yield bottom, dirs, nondirs

    new_path = os.path.realpath(os.path.join(bottom, ".."))

    # see if we are at the top
    if new_path == bottom:
        return

    for x in walk_up(new_path):
        yield x


def find_pipfile(max_depth=3):
    """Returns the path of a Pipfile in parent directories."""
    i = 0
    for c, _, _ in walk_up(os.getcwd()):
        i += 1

        if i < max_depth:
            if "Pipfile":
                p = os.path.join(c, "Pipfile")
                if os.path.isfile(p):
                    return p
    raise RuntimeError("No Pipfile found!")


def ensure_pipfile(project, validate=True, skip_requirements=False, system=False):
    """Creates a Pipfile for the project, if it doesn't exist."""

    # Assert Pipfile exists.
    python = (
        project._which("python")
        if not (project.s.USING_DEFAULT_PYTHON or system)
        else None
    )
    if project.pipfile_is_empty:
        # Show an error message and exit if system is passed and no pipfile exists
        if system and not project.s.PIPENV_VIRTUALENV:
            raise exceptions.PipenvOptionsError(
                "--system",
                "--system is intended to be used for pre-existing Pipfile "
                "installation, not installation of specific packages. Aborting.",
            )
        # If there's a requirements file, but no Pipfile...
        if project.requirements_exists and not skip_requirements:
            requirements_dir_path = os.path.dirname(project.requirements_location)
            click.echo(
                "{0} found in {1} instead of {2}! Converting...".format(
                    click.style("requirements.txt", bold=True),
                    click.style(requirements_dir_path, fg="yellow", bold=True),
                    click.style("Pipfile", bold=True),
                )
            )
            # Create a Pipfile...
            project.create_pipfile(python=python)
            with console.status(
                "Importing requirements...", spinner=project.s.PIPENV_SPINNER
            ) as st:
                # Import requirements.txt.
                try:
                    import_requirements(project)
                except Exception:
                    err.print(environments.PIPENV_SPINNER_FAIL_TEXT.format("Failed..."))
                else:
                    st.console.print(
                        environments.PIPENV_SPINNER_OK_TEXT.format("Success!")
                    )
            # Warn the user of side-effects.
            click.echo(
                "{0}: Your {1} now contains pinned versions, if your {2} did. \n"
                "We recommend updating your {1} to specify the {3} version, instead."
                "".format(
                    click.style("Warning", fg="red", bold=True),
                    click.style("Pipfile", bold=True),
                    click.style("requirements.txt", bold=True),
                    click.style('"*"', bold=True),
                )
            )
        else:
            click.secho("Creating a Pipfile for this project...", bold=True, err=True)
            # Create the pipfile if it doesn't exist.
            project.create_pipfile(python=python)
    # Validate the Pipfile's contents.
    if validate and project.virtualenv_exists and not project.s.PIPENV_SKIP_VALIDATION:
        # Ensure that Pipfile is using proper casing.
        p = project.parsed_pipfile
        changed = project.ensure_proper_casing()
        # Write changes out to disk.
        if changed:
            click.echo(
                click.style("Fixing package names in Pipfile...", bold=True), err=True
            )
            project.write_toml(p)