# Copyright Spack Project Developers. See COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

import contextlib
import os
import pathlib
import sys

import pytest

import spack.cmd
import spack.config
import spack.extensions
import spack.main


class Extension:
    """Helper class to simplify the creation of simple command extension
    directory structures with a conventional format for testing.
    """

    def __init__(self, name, root: pathlib.Path):
        """Create a command extension.

        Args:
            name (str): The name of the command extension.
            root (path object): The temporary root for the command extension
                (e.g. from tmp_path.mkdir()).
        """
        self.name = name
        self.pname = spack.cmd.python_name(name)
        self.root = root
        self.main = self.root / self.pname
        self.main.mkdir(parents=True, exist_ok=True)
        self.cmd = self.main / "cmd"
        self.cmd.mkdir(parents=True, exist_ok=True)

    def add_command(self, command_name, contents):
        """Add a command to this command extension.

        Args:
            command_name (str): The name of the command.
            contents (str): the desired contents of the new command module
                file."""
        spack.cmd.require_cmd_name(command_name)
        python_name = spack.cmd.python_name(command_name)
        cmd = self.cmd / (python_name + ".py")
        cmd.write_text(contents)


@pytest.fixture(scope="function")
def extension_creator(tmp_path: pathlib.Path, config):
    """Create a basic extension command directory structure"""

    @contextlib.contextmanager
    def _ce(extension_name="testcommand"):
        root = tmp_path / ("spack-" + extension_name)
        root.mkdir()
        extension = Extension(extension_name, root)
        with spack.config.override("config:extensions", [str(extension.root)]):
            yield extension

    list_of_modules = list(sys.modules.keys())
    try:
        yield _ce
    finally:
        to_be_deleted = [x for x in sys.modules if x not in list_of_modules]
        for module_name in to_be_deleted:
            del sys.modules[module_name]


@pytest.fixture(scope="function")
def hello_world_extension(extension_creator):
    """Create an extension with a hello-world command."""
    with extension_creator() as extension:
        extension.add_command(
            "hello-world",
            """
description = "hello world extension command"
section = "test command"
level = "long"

def setup_parser(subparser):
    pass


def hello_world(parser, args):
    print('Hello world!')
""",
        )
        yield extension


@pytest.fixture(scope="function")
def hello_world_cmd(hello_world_extension):
    """Create and return an invokable "hello-world" extension command."""
    yield spack.main.SpackCommand("hello-world")


@pytest.fixture(scope="function")
def hello_world_with_module_in_root(extension_creator):
    """Create a "hello-world" extension command with additional code in the
    root folder.
    """

    @contextlib.contextmanager
    def _hwwmir(extension_name=None):
        with (
            extension_creator(extension_name) if extension_name else extension_creator()
        ) as extension:
            # Note that the namespace of the extension is derived from the
            # fixture.
            extension.add_command(
                "hello",
                """
# Test an absolute import
from spack.extensions.{ext_pname}.implementation import hello_world

# Test a relative import
from ..implementation import hello_folks

description = "hello world extension command"
section = "test command"
level = "long"

# Test setting a global variable in setup_parser and retrieving
# it in the command
global_message = 'foo'

def setup_parser(subparser):
    sp = subparser.add_subparsers(metavar='SUBCOMMAND', dest='subcommand')
    global global_message
    sp.add_parser('world', help='Print Hello world!')
    sp.add_parser('folks', help='Print Hello folks!')
    sp.add_parser('global', help='Print Hello folks!')
    global_message = 'bar'

def hello(parser, args):
    if args.subcommand == 'world':
        hello_world()
    elif args.subcommand == 'folks':
        hello_folks()
    elif args.subcommand == 'global':
        print(global_message)
""".format(
                    ext_pname=extension.pname
                ),
            )

            init_file = extension.main / "__init__.py"
            init_file.touch()
            implementation = extension.main / "implementation.py"
            implementation.write_text(
                """
def hello_world():
    print('Hello world!')

def hello_folks():
    print('Hello folks!')
"""
            )
            yield spack.main.SpackCommand("hello")

    yield _hwwmir


def test_simple_command_extension(hello_world_cmd):
    """Basic test of a functioning command."""
    output = hello_world_cmd()
    assert "Hello world!" in output


def test_multi_extension_search(hello_world_extension, extension_creator):
    """Ensure we can find an extension command even if it's not in the first
    place we look.
    """

    with extension_creator("testcommand2"):
        assert ("Hello world") in spack.main.SpackCommand("hello-world")()


def test_duplicate_module_load(hello_world_cmd, capsys):
    """Ensure duplicate module load attempts are successful.

    The command module will already have been loaded once by the
    hello_world_cmd fixture.
    """
    parser = spack.main.make_argument_parser()
    args = []
    hw_cmd = spack.cmd.get_command(hello_world_cmd.command_name)
    hw_cmd(parser, args)
    captured = capsys.readouterr()
    assert captured == ("Hello world!\n", "")


@pytest.mark.parametrize(
    "extension_name", [None, "hyphenated-extension"], ids=["simple", "hyphenated_extension_name"]
)
def test_command_with_import(extension_name, hello_world_with_module_in_root):
    """Ensure we can write a functioning command with multiple imported
    subcommands, including where the extension name contains a hyphen.
    """
    with hello_world_with_module_in_root(extension_name) as hello_world:
        output = hello_world("world")
        assert "Hello world!" in output
        output = hello_world("folks")
        assert "Hello folks!" in output
        output = hello_world("global")
        assert "bar" in output


def test_missing_command():
    """Ensure that we raise the expected exception if the desired command is
    not present.
    """
    with pytest.raises(spack.cmd.CommandNotFoundError):
        spack.cmd.get_module("no-such-command")


@pytest.mark.parametrize(
    "extension_path,expected_exception",
    [
        ("/my/bad/extension", spack.extensions.ExtensionNamingError),
        ("", spack.extensions.ExtensionNamingError),
        ("/my/bad/spack--extra-hyphen", spack.extensions.ExtensionNamingError),
        ("/my/good/spack-extension", spack.cmd.CommandNotFoundError),
        ("/my/still/good/spack-extension/", spack.cmd.CommandNotFoundError),
        ("/my/spack-hyphenated-extension", spack.cmd.CommandNotFoundError),
    ],
    ids=["no_stem", "vacuous", "leading_hyphen", "basic_good", "trailing_slash", "hyphenated"],
)
def test_extension_naming(tmp_path: pathlib.Path, extension_path, expected_exception, config):
    """Ensure that we are correctly validating configured extension paths
    for conformity with the rules: the basename should match
    ``spack-<name>``; <name> may have embedded hyphens but not begin with one.
    """
    # NOTE: if the directory is a valid extension directory name the "vacuous" test will
    # fail because it resolves to current working directory
    import spack.llnl.util.filesystem as fs

    with fs.working_dir(str(tmp_path)):
        with spack.config.override("config:extensions", [extension_path]):
            with pytest.raises(expected_exception):
                spack.cmd.get_module("no-such-command")


def test_missing_command_function(extension_creator, capsys):
    """Ensure we die as expected if a command module does not have the
    expected command function defined.
    """
    with extension_creator() as extension:
        extension.add_command("bad-cmd", """\ndescription = "Empty command implementation"\n""")
        with pytest.raises(SystemExit):
            spack.cmd.get_module("bad-cmd")
        capture = capsys.readouterr()
        assert "must define function 'bad_cmd'." in capture[1]


def test_get_command_paths(config):
    """Exercise the construction of extension command search paths."""
    extensions = ("extension-1", "extension-2")
    ext_paths = []
    expected_cmd_paths = []
    for ext in extensions:
        ext_path = os.path.join("my", "path", "to", "spack-" + ext)
        ext_paths.append(ext_path)
        path = os.path.join(ext_path, spack.cmd.python_name(ext), "cmd")
        path = os.path.abspath(path)
        expected_cmd_paths.append(path)

    with spack.config.override("config:extensions", ext_paths):
        assert spack.extensions.get_command_paths() == expected_cmd_paths


def test_variable_in_extension_path(config, working_env):
    """Test variables in extension paths."""
    os.environ["_MY_VAR"] = os.path.join("my", "var")
    ext_paths = [os.path.join("~", "${_MY_VAR}", "spack-extension-1")]
    # Home env variable is USERPROFILE on Windows
    home_env = "USERPROFILE" if sys.platform == "win32" else "HOME"
    expected_ext_paths = [
        os.path.join(os.environ[home_env], os.environ["_MY_VAR"], "spack-extension-1")
    ]
    with spack.config.override("config:extensions", ext_paths):
        assert spack.extensions.get_extension_paths() == expected_ext_paths


@pytest.mark.parametrize(
    "command_name,contents,exception",
    [
        ("bad-cmd", "from oopsie.daisy import bad\n", ImportError),
        ("bad-cmd", """var = bad_function_call('blech')\n""", NameError),
        ("bad-cmd", ")\n", SyntaxError),
    ],
    ids=["ImportError", "NameError", "SyntaxError"],
)
def test_failing_command(command_name, contents, exception, extension_creator):
    """Ensure that the configured command fails to import with the specified
    error.
    """
    with extension_creator() as extension:
        extension.add_command(command_name, contents)
        with pytest.raises(exception):
            spack.extensions.get_module(command_name)
