# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.

import os
import sys
import json
import pytest
import shutil
import urllib.parse

from binascii import hexlify

import tornado
from tornado.escape import url_escape
import jupyter_core.paths
import nbformat
from traitlets.config import Config

from jupyter_server.extension import serverextension
from jupyter_server.serverapp import ServerApp
from jupyter_server.utils import url_path_join
from jupyter_server.services.contents.filemanager import FileContentsManager
from jupyter_server.services.contents.largefilemanager import LargeFileManager


# List of dependencies needed for this plugin.
pytest_plugins = [
    "pytest_tornasync",
    # Once the chunk below moves to Jupyter Core, we'll uncomment
    # This plugin and use the fixtures directly from Jupyter Core.
    # "jupyter_core.pytest_plugin"
]


import asyncio
if os.name == "nt" and sys.version_info >= (3, 7):
    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())


# ============ Move to Jupyter Core =============

def mkdir(tmp_path, *parts):
    path = tmp_path.joinpath(*parts)
    if not path.exists():
        path.mkdir(parents=True)
    return path


@pytest.fixture
def jp_home_dir(tmp_path):
    """Provides a temporary HOME directory value."""
    return mkdir(tmp_path, "home")


@pytest.fixture
def jp_data_dir(tmp_path):
    """Provides a temporary Jupyter data dir directory value."""
    return mkdir(tmp_path, "data")


@pytest.fixture
def jp_config_dir(tmp_path):
    """Provides a temporary Jupyter config dir directory value."""
    return mkdir(tmp_path, "config")


@pytest.fixture
def jp_runtime_dir(tmp_path):
    """Provides a temporary Jupyter runtime dir directory value."""
    return mkdir(tmp_path, "runtime")


@pytest.fixture
def jp_system_jupyter_path(tmp_path):
    """Provides a temporary Jupyter system path value."""
    return mkdir(tmp_path, "share", "jupyter")


@pytest.fixture
def jp_env_jupyter_path(tmp_path):
    """Provides a temporary Jupyter env system path value."""
    return mkdir(tmp_path, "env", "share", "jupyter")


@pytest.fixture
def jp_system_config_path(tmp_path):
    """Provides a temporary Jupyter config path value."""
    return mkdir(tmp_path, "etc", "jupyter")


@pytest.fixture
def jp_env_config_path(tmp_path):
    """Provides a temporary Jupyter env config path value."""
    return mkdir(tmp_path, "env", "etc", "jupyter")


@pytest.fixture
def jp_environ(
    monkeypatch,
    tmp_path,
    jp_home_dir,
    jp_data_dir,
    jp_config_dir,
    jp_runtime_dir,
    jp_system_jupyter_path,
    jp_system_config_path,
    jp_env_jupyter_path,
    jp_env_config_path,
):
    """Configures a temporary environment based on Jupyter-specific environment variables. """
    monkeypatch.setenv("HOME", str(jp_home_dir))
    monkeypatch.setenv("PYTHONPATH", os.pathsep.join(sys.path))
    # monkeypatch.setenv("JUPYTER_NO_CONFIG", "1")
    monkeypatch.setenv("JUPYTER_CONFIG_DIR", str(jp_config_dir))
    monkeypatch.setenv("JUPYTER_DATA_DIR", str(jp_data_dir))
    monkeypatch.setenv("JUPYTER_RUNTIME_DIR", str(jp_runtime_dir))
    monkeypatch.setattr(
        jupyter_core.paths, "SYSTEM_JUPYTER_PATH", [str(jp_system_jupyter_path)]
    )
    monkeypatch.setattr(jupyter_core.paths, "ENV_JUPYTER_PATH", [str(jp_env_jupyter_path)])
    monkeypatch.setattr(
        jupyter_core.paths, "SYSTEM_CONFIG_PATH", [str(jp_system_config_path)]
    )
    monkeypatch.setattr(jupyter_core.paths, "ENV_CONFIG_PATH", [str(jp_env_config_path)])


# ================= End: Move to Jupyter core ================

@pytest.fixture
def jp_server_config():
    """Allows tests to setup their specific configuration values. """
    return {}


@pytest.fixture
def jp_root_dir(tmp_path):
    """Provides a temporary Jupyter root directory value."""
    return mkdir(tmp_path, "root_dir")


@pytest.fixture
def jp_template_dir(tmp_path):
    """Provides a temporary Jupyter templates directory value."""
    return mkdir(tmp_path, "templates")


@pytest.fixture
def jp_argv():
    """Allows tests to setup specific argv values. """
    return []


@pytest.fixture
def jp_extension_environ(jp_env_config_path, monkeypatch):
    """Monkeypatch a Jupyter Extension's config path into each test's environment variable"""
    monkeypatch.setattr(serverextension, "ENV_CONFIG_PATH", [str(jp_env_config_path)])


@pytest.fixture
def jp_http_port(http_server_port):
    """Returns the port value from the http_server_port fixture. """
    return http_server_port[-1]


@pytest.fixture
def jp_nbconvert_templates(jp_data_dir):
    """Setups up a temporary directory consisting of the nbconvert templates."""

    # Get path to nbconvert template directory *before*
    # monkeypatching the paths env variable via the jp_environ fixture.
    possible_paths = jupyter_core.paths.jupyter_path('nbconvert', 'templates')
    nbconvert_path = None
    for path in possible_paths:
        if os.path.exists(path):
            nbconvert_path = path
            break

    nbconvert_target = jp_data_dir / 'nbconvert' / 'templates'

    # copy nbconvert templates to new tmp data_dir.
    if nbconvert_path:
        shutil.copytree(nbconvert_path, str(nbconvert_target))


@pytest.fixture(scope='function')
def jp_configurable_serverapp(
    jp_nbconvert_templates,  # this fixture must preceed jp_environ
    jp_environ,
    jp_server_config,
    jp_argv,
    jp_http_port,
    jp_base_url,
    tmp_path,
    jp_root_dir,
    io_loop,
):
    """Starts a Jupyter Server instance based on
    the provided configuration values.

    The fixture is a factory; it can be called like
    a function inside a unit test. Here's a basic
    example of how use this fixture:

    .. code-block:: python

        def my_test(jp_configurable_serverapp):

            app = jp_configurable_serverapp(...)
            ...
    """
    ServerApp.clear_instance()

    def _configurable_serverapp(
        config=jp_server_config,
        base_url=jp_base_url,
        argv=jp_argv,
        environ=jp_environ,
        http_port=jp_http_port,
        tmp_path=tmp_path,
        root_dir=jp_root_dir,
        **kwargs
    ):
        c = Config(config)
        c.NotebookNotary.db_file = ":memory:"
        token = hexlify(os.urandom(4)).decode("ascii")
        app = ServerApp.instance(
            # Set the log level to debug for testing purposes
            log_level='DEBUG',
            port=http_port,
            port_retries=0,
            open_browser=False,
            root_dir=str(root_dir),
            base_url=base_url,
            config=c,
            allow_root=True,
            token=token,
            **kwargs
        )

        app.init_signal = lambda: None
        app.log.propagate = True
        app.log.handlers = []
        # Initialize app without httpserver
        app.initialize(argv=argv, new_httpserver=False)
        app.log.propagate = True
        app.log.handlers = []
        # Start app without ioloop
        app.start_app()
        return app

    return _configurable_serverapp


@pytest.fixture
def jp_ensure_app_fixture(request):
    """Ensures that the 'app' fixture used by pytest-tornasync
    is set to `jp_web_app`, the Tornado Web Application returned
    by the ServerApp in Jupyter Server, provided by the jp_web_app
    fixture in this module.

    Note, this hardcodes the `app_fixture` option from
    pytest-tornasync to `jp_web_app`. If this value is configured
    to something other than the default, it will raise an exception.
    """
    app_option = request.config.getoption("app_fixture")
    if app_option not in ["app", "jp_web_app"]:
        raise Exception("jp_serverapp requires the `app-fixture` option "
                        "to be set to 'jp_web_app`. Try rerunning the "
                        "current tests with the option `--app-fixture "
                        "jp_web_app`.")
    elif app_option == "app":
        # Manually set the app_fixture to `jp_web_app` if it's
        # not set already.
        request.config.option.app_fixture = "jp_web_app"


@pytest.fixture(scope="function")
def jp_serverapp(
    jp_ensure_app_fixture,
    jp_server_config,
    jp_argv,
    jp_configurable_serverapp
):
    """Starts a Jupyter Server instance based on the established configuration values."""
    app = jp_configurable_serverapp(config=jp_server_config, argv=jp_argv)
    yield app
    app._cleanup()


@pytest.fixture
def jp_web_app(jp_serverapp):
    """app fixture is needed by pytest_tornasync plugin"""
    return jp_serverapp.web_app


@pytest.fixture
def jp_auth_header(jp_serverapp):
    """Configures an authorization header using the token from the serverapp fixture."""
    return {"Authorization": "token {token}".format(token=jp_serverapp.token)}


@pytest.fixture
def jp_base_url():
    """Returns the base url to use for the test."""
    return "/a%40b/"


@pytest.fixture
def jp_fetch(jp_serverapp, http_server_client, jp_auth_header, jp_base_url):
    """Sends an (asynchronous) HTTP request to a test server.

    The fixture is a factory; it can be called like
    a function inside a unit test. Here's a basic
    example of how use this fixture:

    .. code-block:: python

        async def my_test(jp_fetch):

            response = await jp_fetch("api", "spec.yaml")
            ...
    """
    def client_fetch(*parts, headers={}, params={}, **kwargs):
        # Handle URL strings
        path_url = url_escape(url_path_join(*parts), plus=False)
        base_path_url = url_path_join(jp_base_url, path_url)
        params_url = urllib.parse.urlencode(params)
        url = base_path_url + "?" + params_url
        # Add auth keys to header
        headers.update(jp_auth_header)
        # Make request.
        return http_server_client.fetch(
            url, headers=headers, request_timeout=20, **kwargs
        )
    return client_fetch


@pytest.fixture
def jp_ws_fetch(jp_serverapp, http_server_client, jp_auth_header, jp_http_port, jp_base_url):
    """Sends a websocket request to a test server.

    The fixture is a factory; it can be called like
    a function inside a unit test. Here's a basic
    example of how use this fixture:

    .. code-block:: python

        async def my_test(jp_fetch, jp_ws_fetch):
            # Start a kernel
            r = await jp_fetch(
                'api', 'kernels',
                method='POST',
                body=json.dumps({
                    'name': "python3"
                })
            )
            kid = json.loads(r.body.decode())['id']

            # Open a websocket connection.
            ws = await jp_ws_fetch(
                'api', 'kernels', kid, 'channels'
            )
            ...
    """
    def client_fetch(*parts, headers={}, params={}, **kwargs):
        # Handle URL strings
        path_url = url_escape(url_path_join(*parts), plus=False)
        base_path_url = url_path_join(jp_base_url, path_url)
        urlparts = urllib.parse.urlparse('ws://localhost:{}'.format(jp_http_port))
        urlparts = urlparts._replace(
            path=base_path_url,
            query=urllib.parse.urlencode(params)
        )
        url = urlparts.geturl()
        # Add auth keys to header
        headers.update(jp_auth_header)
        # Make request.
        req = tornado.httpclient.HTTPRequest(
            url,
            headers=jp_auth_header,
            connect_timeout=120
        )
        return tornado.websocket.websocket_connect(req)
    return client_fetch


some_resource = u"The very model of a modern major general"
sample_kernel_json = {
    'argv':['cat', '{connection_file}'],
    'display_name': 'Test kernel',
}
@pytest.fixture
def jp_kernelspecs(jp_data_dir):
    """Configures some sample kernelspecs in the Jupyter data directory."""
    spec_names = ['sample', 'sample 2']
    for name in spec_names:
        sample_kernel_dir = jp_data_dir.joinpath('kernels', name)
        sample_kernel_dir.mkdir(parents=True)
        # Create kernel json file
        sample_kernel_file = sample_kernel_dir.joinpath('kernel.json')
        sample_kernel_file.write_text(json.dumps(sample_kernel_json))
        # Create resources text
        sample_kernel_resources = sample_kernel_dir.joinpath('resource.txt')
        sample_kernel_resources.write_text(some_resource)


@pytest.fixture(params=[True, False])
def jp_contents_manager(request, tmp_path):
    """Returns a FileContentsManager instance based on the use_atomic_writing parameter value."""
    return FileContentsManager(root_dir=str(tmp_path), use_atomic_writing=request.param)


@pytest.fixture
def jp_large_contents_manager(tmp_path):
    """Returns a LargeFileManager instance."""
    return LargeFileManager(root_dir=str(tmp_path))


@pytest.fixture
def jp_create_notebook(jp_root_dir):
    """Creates a notebook in the test's home directory."""
    def inner(nbpath):
        nbpath = jp_root_dir.joinpath(nbpath)
        # Check that the notebook has the correct file extension.
        if nbpath.suffix != '.ipynb':
            raise Exception("File extension for notebook must be .ipynb")
        # If the notebook path has a parent directory, make sure it's created.
        parent = nbpath.parent
        parent.mkdir(parents=True, exist_ok=True)
        # Create a notebook string and write to file.
        nb = nbformat.v4.new_notebook()
        nbtext = nbformat.writes(nb, version=4)
        nbpath.write_text(nbtext)
    return inner


@pytest.fixture(autouse=True)
def jp_server_cleanup():
    yield
    ServerApp.clear_instance()
