from functools import partial
import io
import json
import platform

import mujson
import pytest
import ujson

import falcon
from falcon import ASGI_SUPPORTED, media, testing
from falcon.util.deprecation import DeprecatedWarning

from _util import create_app  # NOQA


orjson = None
rapidjson = None
try:
    import rapidjson  # type: ignore
except ImportError:
    pass

if platform.python_implementation() == 'CPython':
    try:
        import orjson  # type: ignore
    except ImportError:
        pass

YEN = b'\xc2\xa5'

SERIALIZATION_PARAM_LIST = [
    # Default json.dumps, with only ascii
    (None, {'test': 'value'}, b'{"test":"value"}'),
    (partial(mujson.dumps, ensure_ascii=True), {'test': 'value'}, b'{"test":"value"}'),
    (ujson.dumps, {'test': 'value'}, b'{"test":"value"}'),
    (
        partial(lambda media, **kwargs: json.dumps([media, kwargs]), ensure_ascii=True),
        {'test': 'value'},
        b'[{"test":"value"},{"ensure_ascii":true}]',
    ),
    # Default json.dumps, with non-ascii characters
    (None, {'yen': YEN.decode()}, b'{"yen":"' + YEN + b'"}'),
]

DESERIALIZATION_PARAM_LIST = [
    (None, b'[1, 2]', [1, 2]),
    (
        partial(
            json.loads, object_hook=lambda data: {k: v.upper() for k, v in data.items()}
        ),
        b'{"key": "value"}',
        {'key': 'VALUE'},
    ),
    (mujson.loads, b'{"test": "value"}', {'test': 'value'}),
    (ujson.loads, b'{"test": "value"}', {'test': 'value'}),
]


if orjson:
    SERIALIZATION_PARAM_LIST += [
        (orjson.dumps, {'test': 'value'}, b'{"test":"value"}'),
    ]

    DESERIALIZATION_PARAM_LIST += [
        (orjson.loads, b'{"test": "value"}', {'test': 'value'}),
    ]
if rapidjson:
    SERIALIZATION_PARAM_LIST += [
        (rapidjson.dumps, {'test': 'value'}, b'{"test":"value"}'),
    ]

    DESERIALIZATION_PARAM_LIST += [
        (rapidjson.loads, b'{"test": "value"}', {'test': 'value'}),
    ]


@pytest.mark.parametrize('func, body, expected', SERIALIZATION_PARAM_LIST)
def test_serialization(asgi, func, body, expected):
    handler = media.JSONHandler(dumps=func)

    args = (body, b'application/javacript')

    if asgi:
        result = falcon.async_to_sync(handler.serialize_async, *args)
    else:
        result = handler.serialize(*args)

    # NOTE(nZac) PyPy and CPython render the final string differently. One
    # includes spaces and the other doesn't. This replace will normalize that.
    assert result.replace(b' ', b'') == expected  # noqa


@pytest.mark.parametrize('func, body, expected', DESERIALIZATION_PARAM_LIST)
def test_deserialization(asgi, func, body, expected):
    handler = media.JSONHandler(loads=func)

    args = ['application/javacript', len(body)]

    if asgi:
        if not ASGI_SUPPORTED:
            pytest.skip('ASGI requires Python 3.6+')

        from falcon.asgi.stream import BoundedStream

        s = BoundedStream(testing.ASGIRequestEventEmitter(body))
        args.insert(0, s)

        result = falcon.async_to_sync(handler.deserialize_async, *args)
    else:
        args.insert(0, io.BytesIO(body))
        result = handler.deserialize(*args)

    assert result == expected


@pytest.mark.parametrize('monkeypatch_resolver', [True, False])
@pytest.mark.parametrize(
    'handler_mt',
    [
        'application/json',
        # NOTE(kgriffs): Include a bogus parameter to validate fuzzy matching logic
        'application/json; answer=42',
    ],
)
def test_deserialization_raises(asgi, handler_mt, monkeypatch_resolver):
    app = create_app(asgi)

    class SuchException(Exception):
        pass

    class FaultyHandler(media.BaseHandler):
        def deserialize(self, stream, content_type, content_length):
            raise SuchException('Wow such error.')

        def deserialize_async(self, stream, content_type, content_length):
            raise SuchException('Wow such error.')

        def serialize(self, media, content_type):
            raise SuchException('Wow such error.')

    handlers = media.Handlers({handler_mt: FaultyHandler()})

    # NOTE(kgriffs): Test the pre-3.0 method. Although undocumented, it was
    #   technically a public method, and so we make sure it still works here.
    if monkeypatch_resolver:

        def _resolve(media_type, default, raise_not_found=True):
            with pytest.warns(DeprecatedWarning, match='This undocumented method'):
                h = handlers.find_by_media_type(
                    media_type, default, raise_not_found=raise_not_found
                )
            return h, None, None

        handlers._resolve = _resolve

    app.req_options.media_handlers = handlers
    app.resp_options.media_handlers = handlers

    class Resource:
        def on_get(self, req, resp):
            resp.media = {}

        def on_post(self, req, resp):
            req.media

    class ResourceAsync:
        async def on_get(self, req, resp):
            resp.media = {}

        async def on_post(self, req, resp):
            # NOTE(kgriffs): In this one case we use the property
            #   instead of get_media(), in order to test that the
            #   alias works as expected.
            await req.media

    app.add_route('/', ResourceAsync() if asgi else Resource())

    # NOTE(kgriffs): Now that we install a default handler for
    #   Exception, we have to clear them to test the path we want
    #   to trigger.
    # TODO(kgriffs): Since we always add a default error handler
    #   for Exception, should we take out the checks in the WSGI/ASGI
    #   callable and just always assume it will be handled? If so,
    #   it makes testing that the right exception is propagated harder;
    #   I suppose we'll have to look at what is logged.
    app._error_handlers.clear()

    with pytest.raises(SuchException):
        testing.simulate_get(app, '/')

    with pytest.raises(SuchException):
        testing.simulate_post(app, '/', json={})


def test_sync_methods_not_overridden(asgi):
    app = create_app(asgi)

    class FaultyHandler(media.BaseHandler):
        pass

    handlers = media.Handlers({'application/json': FaultyHandler()})
    app.req_options.media_handlers = handlers
    app.resp_options.media_handlers = handlers

    class Resource:
        def on_get(self, req, resp):
            resp.media = {}

        def on_post(self, req, resp):
            req.media

    class ResourceAsync:
        async def on_get(self, req, resp):
            resp.media = {}

        async def on_post(self, req, resp):
            await req.get_media()

    app.add_route('/', ResourceAsync() if asgi else Resource())

    # NOTE(caselit): force serialization in xml,
    # since error.to_json uses the faulty handler
    result = testing.simulate_get(app, '/', headers={'Accept': 'text/xml'})
    assert result.status_code == 500

    result = testing.simulate_post(app, '/', json={}, headers={'Accept': 'text/xml'})
    assert result.status_code == 500


def test_async_methods_not_overridden():
    app = create_app(asgi=True)

    class SimpleHandler(media.BaseHandler):
        def serialize(self, media, content_type):
            return json.dumps(media).encode()

        def deserialize(self, stream, content_type, content_length):
            return json.load(stream)

    handlers = media.Handlers({'application/json': SimpleHandler()})
    app.req_options.media_handlers = handlers
    app.resp_options.media_handlers = handlers

    class ResourceAsync:
        async def on_post(self, req, resp):
            resp.media = await req.get_media()

    app.add_route('/', ResourceAsync())

    doc = {'event': 'serialized'}
    result = testing.simulate_post(app, '/', json=doc)
    assert result.status_code == 200
    assert result.json == doc


def test_async_handler_returning_none():
    app = create_app(asgi=True)

    class SimpleHandler(media.BaseHandler):
        def serialize(self, media, content_type):
            return json.dumps(media).encode()

        def deserialize(self, stream, content_type, content_length):
            return None

    handlers = media.Handlers({'application/json': SimpleHandler()})
    app.req_options.media_handlers = handlers
    app.resp_options.media_handlers = handlers

    class ResourceAsync:
        async def on_post(self, req, resp):
            resp.media = [await req.get_media()]

    app.add_route('/', ResourceAsync())

    doc = {'event': 'serialized'}
    result = testing.simulate_post(app, '/', json=doc)
    assert result.status_code == 200
    assert result.json == [None]


@pytest.mark.parametrize('monkeypatch_resolver', [True, False])
def test_json_err_no_handler(asgi, monkeypatch_resolver):
    app = create_app(asgi)

    handlers = media.Handlers({falcon.MEDIA_URLENCODED: media.URLEncodedFormHandler()})

    # NOTE(kgriffs): Test the pre-3.0 method. Although undocumented, it was
    #   technically a public method, and so we make sure it still works here.
    if monkeypatch_resolver:

        def _resolve(media_type, default, raise_not_found=True):
            with pytest.warns(DeprecatedWarning, match='This undocumented method'):
                h = handlers.find_by_media_type(
                    media_type, default, raise_not_found=raise_not_found
                )
            return h, None, None

        handlers._resolve = _resolve

    app.req_options.media_handlers = handlers
    app.resp_options.media_handlers = handlers

    class Resource:
        def on_get(self, req, resp):
            raise falcon.HTTPForbidden()

    app.add_route('/', Resource())

    result = testing.simulate_get(app, '/')
    assert result.status_code == 403
    assert result.json == falcon.HTTPForbidden().to_dict()


class TestBaseHandler:
    def test_defaultError(self):
        h = media.BaseHandler()

        def test(call):
            with pytest.raises(NotImplementedError) as e:
                call()

            assert e.value.args == ()

        test(lambda: h.serialize({}, 'my-type'))
        test(lambda: h.deserialize('', 'my-type', 0))

    def test_json(self):
        h = media.BaseHandler()

        with pytest.raises(
            NotImplementedError, match='The JSON media handler requires'
        ):
            h.serialize({}, falcon.MEDIA_JSON)
        with pytest.raises(
            NotImplementedError, match='The JSON media handler requires'
        ):
            h.deserialize('', falcon.MEDIA_JSON, 0)

        with pytest.raises(
            NotImplementedError, match='The JSON media handler requires'
        ):
            h.serialize({}, falcon.MEDIA_JSON + '; charset=UTF-8')
        with pytest.raises(
            NotImplementedError, match='The JSON media handler requires'
        ):
            h.deserialize('', falcon.MEDIA_JSON + '; charset=UTF-8', 0)
