import json
import logging
import os
from io import BytesIO
from typing import Dict
from unittest.mock import MagicMock

import attr
import twisted.logger
from OpenSSL import crypto
from twisted.internet import address
from twisted.internet._resolver import SimpleResolverComplexifier
from twisted.internet.defer import fail, succeed
from twisted.internet.error import DNSLookupError
from twisted.internet.interfaces import (
    IHostnameResolver,
    IReactorPluggableNameResolver,
    IResolverSimple,
)
from twisted.test.proto_helpers import MemoryReactorClock
from twisted.web.http import unquote
from twisted.web.http_headers import Headers
from twisted.web.server import Request, Site
from zope.interface import implementer

from sydent.config import SydentConfig
from sydent.sydent import Sydent

# Expires on Jan 11 2030 at 17:53:40 GMT
FAKE_SERVER_CERT_PEM = """
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
"""


def make_sydent(test_config={}):
    """Create a new sydent

    Args:
        test_config (dict): any configuration variables for overriding the default sydent
            config
    """
    # Use an in-memory SQLite database. Note that the database isn't cleaned up between
    # tests, so by default the same database will be used for each test if changed to be
    # a file on disk.
    if "db" not in test_config:
        test_config["db"] = {"db.file": ":memory:"}
    else:
        test_config["db"].setdefault("db.file", ":memory:")

    reactor = ResolvingMemoryReactorClock()

    sydent_config = SydentConfig()
    sydent_config.parse_config_dict(test_config)

    return Sydent(
        reactor=reactor,
        sydent_config=sydent_config,
        use_tls_for_federation=False,
    )


@attr.s
class FakeChannel:
    """
    A fake Twisted Web Channel (the part that interfaces with the
    wire). Mostly copied from Synapse's tests framework.
    """

    site = attr.ib(type=Site)
    _reactor = attr.ib()
    result = attr.ib(default=attr.Factory(dict))
    _producer = None

    @property
    def json_body(self):
        if not self.result:
            raise Exception("No result yet.")
        return json.loads(self.result["body"].decode("utf8"))

    @property
    def code(self):
        if not self.result:
            raise Exception("No result yet.")
        return int(self.result["code"])

    @property
    def headers(self):
        if not self.result:
            raise Exception("No result yet.")
        h = Headers()
        for i in self.result["headers"]:
            h.addRawHeader(*i)
        return h

    def writeHeaders(self, version, code, reason, headers):
        self.result["version"] = version
        self.result["code"] = code
        self.result["reason"] = reason
        self.result["headers"] = headers

    def write(self, content):
        assert isinstance(content, bytes), "Should be bytes! " + repr(content)

        if "body" not in self.result:
            self.result["body"] = b""

        self.result["body"] += content

    def registerProducer(self, producer, streaming):
        self._producer = producer
        self.producerStreaming = streaming

        def _produce():
            if self._producer:
                self._producer.resumeProducing()
                self._reactor.callLater(0.1, _produce)

        if not streaming:
            self._reactor.callLater(0.0, _produce)

    def unregisterProducer(self):
        if self._producer is None:
            return

        self._producer = None

    def requestDone(self, _self):
        self.result["done"] = True

    def getPeer(self):
        # We give an address so that getClientAddress().host returns a non null entry,
        # causing us to record the MAU
        return address.IPv4Address("TCP", "127.0.0.1", 3423)

    def getHost(self):
        return None

    @property
    def transport(self):
        return self

    def getPeerCertificate(self):
        """Returns the hardcoded TLS certificate for fake.server."""
        return crypto.load_certificate(crypto.FILETYPE_PEM, FAKE_SERVER_CERT_PEM)


class FakeSite:
    """A fake Twisted Web Site."""

    pass


def make_request(
    reactor,
    method,
    path,
    content=b"",
    access_token=None,
    request=Request,
    shorthand=True,
    federation_auth_origin=None,
):
    """
    Make a web request using the given method and path, feed it the
    content, and return the Request and the Channel underneath. Mostly

    Args:
        reactor (IReactor): The Twisted reactor to use when performing the request.
        method (bytes or unicode): The HTTP request method ("verb").
        path (bytes or unicode): The HTTP path, suitably URL encoded (e.g.
        escaped UTF-8 & spaces and such).
        content (bytes or dict): The body of the request. JSON-encoded, if
        a dict.
        access_token (unicode): An access token to use to authenticate the request,
            None if no access token needs to be included.
        request (IRequest): The class to use when instantiating the request object.
        shorthand: Whether to try and be helpful and prefix the given URL
        with the usual REST API path, if it doesn't contain it.
        federation_auth_origin (bytes|None): if set to not-None, we will add a fake
            Authorization header pretenting to be the given server name.

    Returns:
        Tuple[synapse.http.site.SynapseRequest, channel]
    """
    if not isinstance(method, bytes):
        method = method.encode("ascii")

    if not isinstance(path, bytes):
        path = path.encode("ascii")

    # Decorate it to be the full path, if we're using shorthand
    if shorthand and not path.startswith(b"/_matrix"):
        path = b"/_matrix/identity/v2/" + path
        path = path.replace(b"//", b"/")

    if not path.startswith(b"/"):
        path = b"/" + path

    if isinstance(content, dict):
        content = json.dumps(content)
    if isinstance(content, str):
        content = content.encode("utf8")

    site = FakeSite()
    channel = FakeChannel(site, reactor)

    req = request(channel)
    req.process = lambda: b""
    req.content = BytesIO(content)
    req.postpath = list(map(unquote, path[1:].split(b"/")))

    if access_token:
        req.requestHeaders.addRawHeader(
            b"Authorization", b"Bearer " + access_token.encode("ascii")
        )

    if federation_auth_origin is not None:
        req.requestHeaders.addRawHeader(
            b"Authorization",
            b"X-Matrix origin=%s,key=,sig=" % (federation_auth_origin,),
        )

    if content:
        req.requestHeaders.addRawHeader(b"Content-Type", b"application/json")

    req.requestReceived(method, path, b"1.1")

    return req, channel


class ToTwistedHandler(logging.Handler):
    """logging handler which sends the logs to the twisted log"""

    tx_log = twisted.logger.Logger()

    def emit(self, record):
        log_entry = self.format(record)
        log_level = record.levelname.lower().replace("warning", "warn")
        self.tx_log.emit(
            twisted.logger.LogLevel.levelWithName(log_level), "{entry}", entry=log_entry
        )


def setup_logging():
    """Configure the python logging appropriately for the tests.

    (Logs will end up in _trial_temp.)
    """
    root_logger = logging.getLogger()

    log_format = "%(asctime)s - %(name)s - %(lineno)d - %(levelname)s" " - %(message)s"

    handler = ToTwistedHandler()
    formatter = logging.Formatter(log_format)
    handler.setFormatter(formatter)
    root_logger.addHandler(handler)

    log_level = os.environ.get("SYDENT_TEST_LOG_LEVEL", "ERROR")
    root_logger.setLevel(log_level)


setup_logging()


@implementer(IReactorPluggableNameResolver)
class ResolvingMemoryReactorClock(MemoryReactorClock):
    """
    A MemoryReactorClock that supports name resolution.
    """

    def __init__(self):
        lookups = self.lookups = {}  # type: Dict[str, str]

        @implementer(IResolverSimple)
        class FakeResolver:
            def getHostByName(self, name, timeout=None):
                if name not in lookups:
                    return fail(DNSLookupError("OH NO: unknown %s" % (name,)))
                return succeed(lookups[name])

        self.nameResolver = SimpleResolverComplexifier(FakeResolver())
        super().__init__()

    def installNameResolver(self, resolver: IHostnameResolver) -> IHostnameResolver:
        raise NotImplementedError()


class AsyncMock(MagicMock):
    async def __call__(self, *args, **kwargs):
        return super().__call__(*args, **kwargs)