import sys
import weakref
from inspect import isawaitable
from urllib.parse import urlsplit

import sentry_sdk
from sentry_sdk import continue_trace
from sentry_sdk.consts import OP
from sentry_sdk.integrations import Integration, DidNotEnable
from sentry_sdk.integrations._wsgi_common import RequestExtractor, _filter_headers
from sentry_sdk.integrations.logging import ignore_logger
from sentry_sdk.tracing import TRANSACTION_SOURCE_COMPONENT, TRANSACTION_SOURCE_URL
from sentry_sdk.utils import (
    capture_internal_exceptions,
    ensure_integration_enabled,
    event_from_exception,
    HAS_REAL_CONTEXTVARS,
    CONTEXTVARS_ERROR_MESSAGE,
    parse_version,
    reraise,
)

from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from collections.abc import Container
    from typing import Any
    from typing import Callable
    from typing import Optional
    from typing import Union
    from typing import Dict

    from sanic.request import Request, RequestParameters
    from sanic.response import BaseHTTPResponse

    from sentry_sdk._types import Event, EventProcessor, ExcInfo, Hint
    from sanic.router import Route

try:
    from sanic import Sanic, __version__ as SANIC_VERSION
    from sanic.exceptions import SanicException
    from sanic.router import Router
    from sanic.handlers import ErrorHandler
except ImportError:
    raise DidNotEnable("Sanic not installed")

old_error_handler_lookup = ErrorHandler.lookup
old_handle_request = Sanic.handle_request
old_router_get = Router.get

try:
    # This method was introduced in Sanic v21.9
    old_startup = Sanic._startup
except AttributeError:
    pass


class SanicIntegration(Integration):
    identifier = "sanic"
    origin = f"auto.http.{identifier}"
    version = None

    def __init__(self, unsampled_statuses=frozenset({404})):
        # type: (Optional[Container[int]]) -> None
        """
        The unsampled_statuses parameter can be used to specify for which HTTP statuses the
        transactions should not be sent to Sentry. By default, transactions are sent for all
        HTTP statuses, except 404. Set unsampled_statuses to None to send transactions for all
        HTTP statuses, including 404.
        """
        self._unsampled_statuses = unsampled_statuses or set()

    @staticmethod
    def setup_once():
        # type: () -> None

        SanicIntegration.version = parse_version(SANIC_VERSION)

        if SanicIntegration.version is None:
            raise DidNotEnable("Unparsable Sanic version: {}".format(SANIC_VERSION))

        if SanicIntegration.version < (0, 8):
            raise DidNotEnable("Sanic 0.8 or newer required.")

        if not HAS_REAL_CONTEXTVARS:
            # We better have contextvars or we're going to leak state between
            # requests.
            raise DidNotEnable(
                "The sanic integration for Sentry requires Python 3.7+ "
                " or the aiocontextvars package." + CONTEXTVARS_ERROR_MESSAGE
            )

        if SANIC_VERSION.startswith("0.8."):
            # Sanic 0.8 and older creates a logger named "root" and puts a
            # stringified version of every exception in there (without exc_info),
            # which our error deduplication can't detect.
            #
            # We explicitly check the version here because it is a very
            # invasive step to ignore this logger and not necessary in newer
            # versions at all.
            #
            # https://github.com/huge-success/sanic/issues/1332
            ignore_logger("root")

        if SanicIntegration.version < (21, 9):
            _setup_legacy_sanic()
            return

        _setup_sanic()


class SanicRequestExtractor(RequestExtractor):
    def content_length(self):
        # type: () -> int
        if self.request.body is None:
            return 0
        return len(self.request.body)

    def cookies(self):
        # type: () -> Dict[str, str]
        return dict(self.request.cookies)

    def raw_data(self):
        # type: () -> bytes
        return self.request.body

    def form(self):
        # type: () -> RequestParameters
        return self.request.form

    def is_json(self):
        # type: () -> bool
        raise NotImplementedError()

    def json(self):
        # type: () -> Optional[Any]
        return self.request.json

    def files(self):
        # type: () -> RequestParameters
        return self.request.files

    def size_of_file(self, file):
        # type: (Any) -> int
        return len(file.body or ())


def _setup_sanic():
    # type: () -> None
    Sanic._startup = _startup
    ErrorHandler.lookup = _sentry_error_handler_lookup


def _setup_legacy_sanic():
    # type: () -> None
    Sanic.handle_request = _legacy_handle_request
    Router.get = _legacy_router_get
    ErrorHandler.lookup = _sentry_error_handler_lookup


async def _startup(self):
    # type: (Sanic) -> None
    # This happens about as early in the lifecycle as possible, just after the
    # Request object is created. The body has not yet been consumed.
    self.signal("http.lifecycle.request")(_context_enter)

    # This happens after the handler is complete. In v21.9 this signal is not
    # dispatched when there is an exception. Therefore we need to close out
    # and call _context_exit from the custom exception handler as well.
    # See https://github.com/sanic-org/sanic/issues/2297
    self.signal("http.lifecycle.response")(_context_exit)

    # This happens inside of request handling immediately after the route
    # has been identified by the router.
    self.signal("http.routing.after")(_set_transaction)

    # The above signals need to be declared before this can be called.
    await old_startup(self)


async def _context_enter(request):
    # type: (Request) -> None
    request.ctx._sentry_do_integration = (
        sentry_sdk.get_client().get_integration(SanicIntegration) is not None
    )

    if not request.ctx._sentry_do_integration:
        return

    weak_request = weakref.ref(request)
    request.ctx._sentry_scope = sentry_sdk.isolation_scope()
    scope = request.ctx._sentry_scope.__enter__()
    scope.clear_breadcrumbs()
    scope.add_event_processor(_make_request_processor(weak_request))

    transaction = continue_trace(
        dict(request.headers),
        op=OP.HTTP_SERVER,
        # Unless the request results in a 404 error, the name and source will get overwritten in _set_transaction
        name=request.path,
        source=TRANSACTION_SOURCE_URL,
        origin=SanicIntegration.origin,
    )
    request.ctx._sentry_transaction = sentry_sdk.start_transaction(
        transaction
    ).__enter__()


async def _context_exit(request, response=None):
    # type: (Request, Optional[BaseHTTPResponse]) -> None
    with capture_internal_exceptions():
        if not request.ctx._sentry_do_integration:
            return

        integration = sentry_sdk.get_client().get_integration(SanicIntegration)

        response_status = None if response is None else response.status

        # This capture_internal_exceptions block has been intentionally nested here, so that in case an exception
        # happens while trying to end the transaction, we still attempt to exit the hub.
        with capture_internal_exceptions():
            request.ctx._sentry_transaction.set_http_status(response_status)
            request.ctx._sentry_transaction.sampled &= (
                isinstance(integration, SanicIntegration)
                and response_status not in integration._unsampled_statuses
            )
            request.ctx._sentry_transaction.__exit__(None, None, None)

        request.ctx._sentry_scope.__exit__(None, None, None)


async def _set_transaction(request, route, **_):
    # type: (Request, Route, **Any) -> None
    if request.ctx._sentry_do_integration:
        with capture_internal_exceptions():
            scope = sentry_sdk.get_current_scope()
            route_name = route.name.replace(request.app.name, "").strip(".")
            scope.set_transaction_name(route_name, source=TRANSACTION_SOURCE_COMPONENT)


def _sentry_error_handler_lookup(self, exception, *args, **kwargs):
    # type: (Any, Exception, *Any, **Any) -> Optional[object]
    _capture_exception(exception)
    old_error_handler = old_error_handler_lookup(self, exception, *args, **kwargs)

    if old_error_handler is None:
        return None

    if sentry_sdk.get_client().get_integration(SanicIntegration) is None:
        return old_error_handler

    async def sentry_wrapped_error_handler(request, exception):
        # type: (Request, Exception) -> Any
        try:
            response = old_error_handler(request, exception)
            if isawaitable(response):
                response = await response
            return response
        except Exception:
            # Report errors that occur in Sanic error handler. These
            # exceptions will not even show up in Sanic's
            # `sanic.exceptions` logger.
            exc_info = sys.exc_info()
            _capture_exception(exc_info)
            reraise(*exc_info)
        finally:
            # As mentioned in previous comment in _startup, this can be removed
            # after https://github.com/sanic-org/sanic/issues/2297 is resolved
            if SanicIntegration.version and SanicIntegration.version == (21, 9):
                await _context_exit(request)

    return sentry_wrapped_error_handler


async def _legacy_handle_request(self, request, *args, **kwargs):
    # type: (Any, Request, *Any, **Any) -> Any
    if sentry_sdk.get_client().get_integration(SanicIntegration) is None:
        return await old_handle_request(self, request, *args, **kwargs)

    weak_request = weakref.ref(request)

    with sentry_sdk.isolation_scope() as scope:
        scope.clear_breadcrumbs()
        scope.add_event_processor(_make_request_processor(weak_request))

        response = old_handle_request(self, request, *args, **kwargs)
        if isawaitable(response):
            response = await response

        return response


def _legacy_router_get(self, *args):
    # type: (Any, Union[Any, Request]) -> Any
    rv = old_router_get(self, *args)
    if sentry_sdk.get_client().get_integration(SanicIntegration) is not None:
        with capture_internal_exceptions():
            scope = sentry_sdk.get_isolation_scope()
            if SanicIntegration.version and SanicIntegration.version >= (21, 3):
                # Sanic versions above and including 21.3 append the app name to the
                # route name, and so we need to remove it from Route name so the
                # transaction name is consistent across all versions
                sanic_app_name = self.ctx.app.name
                sanic_route = rv[0].name

                if sanic_route.startswith("%s." % sanic_app_name):
                    # We add a 1 to the len of the sanic_app_name because there is a dot
                    # that joins app name and the route name
                    # Format: app_name.route_name
                    sanic_route = sanic_route[len(sanic_app_name) + 1 :]

                scope.set_transaction_name(
                    sanic_route, source=TRANSACTION_SOURCE_COMPONENT
                )
            else:
                scope.set_transaction_name(
                    rv[0].__name__, source=TRANSACTION_SOURCE_COMPONENT
                )

    return rv


@ensure_integration_enabled(SanicIntegration)
def _capture_exception(exception):
    # type: (Union[ExcInfo, BaseException]) -> None
    with capture_internal_exceptions():
        event, hint = event_from_exception(
            exception,
            client_options=sentry_sdk.get_client().options,
            mechanism={"type": "sanic", "handled": False},
        )

        if hint and hasattr(hint["exc_info"][0], "quiet") and hint["exc_info"][0].quiet:
            return

        sentry_sdk.capture_event(event, hint=hint)


def _make_request_processor(weak_request):
    # type: (Callable[[], Request]) -> EventProcessor
    def sanic_processor(event, hint):
        # type: (Event, Optional[Hint]) -> Optional[Event]

        try:
            if hint and issubclass(hint["exc_info"][0], SanicException):
                return None
        except KeyError:
            pass

        request = weak_request()
        if request is None:
            return event

        with capture_internal_exceptions():
            extractor = SanicRequestExtractor(request)
            extractor.extract_into_event(event)

            request_info = event["request"]
            urlparts = urlsplit(request.url)

            request_info["url"] = "%s://%s%s" % (
                urlparts.scheme,
                urlparts.netloc,
                urlparts.path,
            )

            request_info["query_string"] = urlparts.query
            request_info["method"] = request.method
            request_info["env"] = {"REMOTE_ADDR": request.remote_addr}
            request_info["headers"] = _filter_headers(dict(request.headers))

        return event

    return sanic_processor
