"""Aiohttp test utils."""
import asyncio
from contextlib import contextmanager
import json as _json
import re
from unittest import mock
from urllib.parse import parse_qs

from aiohttp import ClientSession
from aiohttp.streams import StreamReader
from yarl import URL

from aiohttp.client_exceptions import ClientResponseError

retype = type(re.compile(''))


def mock_stream(data):
    """Mock a stream with data."""
    protocol = mock.Mock(_reading_paused=False)
    stream = StreamReader(protocol)
    stream.feed_data(data)
    stream.feed_eof()
    return stream


class AiohttpClientMocker:
    """Mock Aiohttp client requests."""

    def __init__(self):
        """Initialize the request mocker."""
        self._mocks = []
        self._cookies = {}
        self.mock_calls = []

    def request(self, method, url, *,
                auth=None,
                status=200,
                text=None,
                data=None,
                content=None,
                json=None,
                params=None,
                headers={},
                exc=None,
                cookies=None):
        """Mock a request."""
        if json is not None:
            text = _json.dumps(json)
        if text is not None:
            content = text.encode('utf-8')
        if content is None:
            content = b''

        if not isinstance(url, retype):
            url = URL(url)
        if params:
            url = url.with_query(params)

        self._mocks.append(AiohttpClientMockResponse(
            method, url, status, content, cookies, exc, headers))

    def get(self, *args, **kwargs):
        """Register a mock get request."""
        self.request('get', *args, **kwargs)

    def put(self, *args, **kwargs):
        """Register a mock put request."""
        self.request('put', *args, **kwargs)

    def post(self, *args, **kwargs):
        """Register a mock post request."""
        self.request('post', *args, **kwargs)

    def delete(self, *args, **kwargs):
        """Register a mock delete request."""
        self.request('delete', *args, **kwargs)

    def options(self, *args, **kwargs):
        """Register a mock options request."""
        self.request('options', *args, **kwargs)

    @property
    def call_count(self):
        """Return the number of requests made."""
        return len(self.mock_calls)

    def clear_requests(self):
        """Reset mock calls."""
        self._mocks.clear()
        self._cookies.clear()
        self.mock_calls.clear()

    def create_session(self, loop):
        """Create a ClientSession that is bound to this mocker."""
        session = ClientSession(loop=loop)
        # Setting directly on `session` will raise deprecation warning
        object.__setattr__(session, '_request', self.match_request)
        return session

    async def match_request(self, method, url, *, data=None, auth=None,
                            params=None, headers=None, allow_redirects=None,
                            timeout=None, json=None):
        """Match a request against pre-registered requests."""
        data = data or json
        url = URL(url)
        if params:
            url = url.with_query(params)

        for response in self._mocks:
            if response.match_request(method, url, params):
                self.mock_calls.append((method, url, data, headers))

                if response.exc:
                    raise response.exc
                return response

        assert False, "No mock registered for {} {} {}".format(method.upper(),
                                                               url, params)


class AiohttpClientMockResponse:
    """Mock Aiohttp client response."""

    def __init__(self, method, url, status, response, cookies=None, exc=None,
                 headers=None):
        """Initialize a fake response."""
        self.method = method
        self._url = url
        self.status = status
        self.response = response
        self.exc = exc

        self._headers = headers or {}
        self._cookies = {}

        if cookies:
            for name, data in cookies.items():
                cookie = mock.MagicMock()
                cookie.value = data
                self._cookies[name] = cookie

    def match_request(self, method, url, params=None):
        """Test if response answers request."""
        if method.lower() != self.method.lower():
            return False

        # regular expression matching
        if isinstance(self._url, retype):
            return self._url.search(str(url)) is not None

        if (self._url.scheme != url.scheme or self._url.host != url.host or
                self._url.path != url.path):
            return False

        # Ensure all query components in matcher are present in the request
        request_qs = parse_qs(url.query_string)
        matcher_qs = parse_qs(self._url.query_string)
        for key, vals in matcher_qs.items():
            for val in vals:
                try:
                    request_qs.get(key, []).remove(val)
                except ValueError:
                    return False

        return True

    @property
    def headers(self):
        """Return content_type."""
        return self._headers

    @property
    def cookies(self):
        """Return dict of cookies."""
        return self._cookies

    @property
    def content(self):
        """Return content."""
        return mock_stream(self.response)

    @asyncio.coroutine
    def read(self):
        """Return mock response."""
        return self.response

    @asyncio.coroutine
    def text(self, encoding='utf-8'):
        """Return mock response as a string."""
        return self.response.decode(encoding)

    @asyncio.coroutine
    def json(self, encoding='utf-8'):
        """Return mock response as a json."""
        return _json.loads(self.response.decode(encoding))

    @asyncio.coroutine
    def release(self):
        """Mock release."""
        pass

    def raise_for_status(self):
        """Raise error if status is 400 or higher."""
        if self.status >= 400:
            raise ClientResponseError(
                None, None, code=self.status, headers=self.headers)

    def close(self):
        """Mock close."""
        pass


@contextmanager
def mock_aiohttp_client():
    """Context manager to mock aiohttp client."""
    mocker = AiohttpClientMocker()

    with mock.patch(
        'homeassistant.helpers.aiohttp_client.async_create_clientsession',
            side_effect=lambda hass, *args: mocker.create_session(hass.loop)):
        yield mocker