import importlib

import _pytest.unittest
import pytest

from irctest.basecontrollers import BaseClientController, BaseServerController
from irctest.cases import BaseClientTestCase, BaseServerTestCase, _IrcTestCase


def pytest_addoption(parser):
    """Called by pytest, registers CLI options passed to the pytest command."""
    parser.addoption(
        "--controller", help="Which module to use to run the tested software."
    )
    parser.addoption(
        "--openssl-bin", type=str, default="openssl", help="The openssl binary to use"
    )


def pytest_configure(config):
    """Called by pytest, after it parsed the command-line."""
    module_name = config.getoption("controller")

    if module_name is None:
        print("Missing --controller option, errors may occur.")
        _IrcTestCase.controllerClass = None
        _IrcTestCase.show_io = True  # TODO
        return

    try:
        module = importlib.import_module(module_name)
    except ImportError:
        pytest.exit("Cannot import module {}".format(module_name), 1)

    controller_class = module.get_irctest_controller_class()
    if issubclass(controller_class, BaseClientController):
        from irctest import client_tests as module
    elif issubclass(controller_class, BaseServerController):
        from irctest import server_tests as module
    else:
        pytest.exit(
            r"{}.Controller should be a subclass of "
            r"irctest.basecontroller.Base{{Client,Server}}Controller".format(
                module_name
            ),
            1,
        )
    _IrcTestCase.controllerClass = controller_class
    _IrcTestCase.controllerClass.openssl_bin = config.getoption("openssl_bin")
    _IrcTestCase.show_io = True  # TODO


def pytest_collection_modifyitems(session, config, items):
    """Called by pytest after finishing the test collection,
    and before actually running the tests.

    This function filters out client tests if running with a server controller,
    and vice versa.
    """

    # First, check if we should run server tests or client tests
    server_tests = client_tests = False
    if _IrcTestCase.controllerClass is None:
        pass
    elif issubclass(_IrcTestCase.controllerClass, BaseServerController):
        server_tests = True
    elif issubclass(_IrcTestCase.controllerClass, BaseClientController):
        client_tests = True
    else:
        assert False, (
            f"{_IrcTestCase.controllerClass} inherits neither "
            f"BaseClientController or BaseServerController"
        )

    filtered_items = []

    # Iterate over each of the test functions (they are pytest "Nodes")
    for item in items:
        assert isinstance(item, _pytest.python.Function)

        # unittest-style test functions have the node of UnitTest class as parent
        assert isinstance(item.parent, _pytest.python.Instance)

        # and that node references the UnitTest class
        assert issubclass(item.parent.cls, _IrcTestCase)

        # and in this project, TestCase classes all inherit either from
        # BaseClientController or BaseServerController.
        if issubclass(item.parent.cls, BaseServerTestCase):
            if server_tests:
                filtered_items.append(item)
        elif issubclass(item.parent.cls, BaseClientTestCase):
            if client_tests:
                filtered_items.append(item)
        else:
            filtered_items.append(item)

    # Finally, rewrite in-place the list of tests pytest will run
    items[:] = filtered_items