# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.
import io
import json
import logging
import os
import shutil
import sys
import urllib.parse
from binascii import hexlify

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

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


# 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
def jp_logging_stream():
    """StringIO stream intended to be used by the core
    Jupyter ServerApp logger's default StreamHandler. This
    helps avoid collision with stdout which is hijacked
    by Pytest.
    """
    logging_stream = io.StringIO()
    yield logging_stream
    output = logging_stream.getvalue()
    # If output exists, print it.
    if output:
        print(output)
    return output


@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,
    jp_logging_stream,
):
    """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)
        # Reroute all logging StreamHandlers away from stdin/stdout since pytest hijacks
        # these streams and closes them at unfortunate times.
        stream_handlers = [h for h in app.log.handlers if isinstance(h, logging.StreamHandler)]
        for handler in stream_handlers:
            handler.setStream(jp_logging_stream)
        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.remove_server_info_file()
    app.remove_browser_open_files()


@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=None, params=None, **kwargs):
        if not headers:
            headers = {}
        if not params:
            params = {}
        # 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=None, params=None, **kwargs):
        if not headers:
            headers = {}
        if not params:
            params = {}
        # 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=headers, 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", "bad"]
    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")
        kernel_json = sample_kernel_json.copy()
        if name == "bad":
            kernel_json["argv"] = ["non_existent_path"]
        sample_kernel_file.write_text(json.dumps(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()


@pytest.fixture
def jp_cleanup_subprocesses(jp_serverapp):
    """Clean up subprocesses started by a Jupyter Server, i.e. kernels and terminal."""

    async def _():
        terminal_cleanup = jp_serverapp.web_app.settings["terminal_manager"].terminate_all
        kernel_cleanup = jp_serverapp.kernel_manager.shutdown_all

        async def kernel_cleanup_steps():
            # Try a graceful shutdown with a timeout
            try:
                await asyncio.wait_for(kernel_cleanup(), timeout=15.0)
            except asyncio.TimeoutError:
                # Now force a shutdown
                try:
                    await asyncio.wait_for(kernel_cleanup(now=True), timeout=15.0)
                except asyncio.TimeoutError:
                    print(Exception("Kernel never shutdown!"))
            except Exception as e:
                print(e)

        if asyncio.iscoroutinefunction(terminal_cleanup):
            try:
                await terminal_cleanup()
            except Exception as e:
                print(e)
        else:
            try:
                await terminal_cleanup()
            except Exception as e:
                print(e)
        if asyncio.iscoroutinefunction(kernel_cleanup):
            await kernel_cleanup_steps()
        else:
            try:
                kernel_cleanup()
            except Exception as e:
                print(e)

    return _