import sys
import warnings
from functools import wraps
from threading import Thread, current_thread
from concurrent.futures import ThreadPoolExecutor, Future

import sentry_sdk
from sentry_sdk.integrations import Integration
from sentry_sdk.scope import use_isolation_scope, use_scope
from sentry_sdk.utils import (
    event_from_exception,
    capture_internal_exceptions,
    logger,
    reraise,
)

from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from typing import Any
    from typing import TypeVar
    from typing import Callable
    from typing import Optional

    from sentry_sdk._types import ExcInfo

    F = TypeVar("F", bound=Callable[..., Any])
    T = TypeVar("T", bound=Any)


class ThreadingIntegration(Integration):
    identifier = "threading"

    def __init__(
        self, propagate_hub: "Optional[bool]" = None, propagate_scope: bool = True
    ) -> None:
        if propagate_hub is not None:
            logger.warning(
                "Deprecated: propagate_hub is deprecated. This will be removed in the future."
            )

        # Note: propagate_hub did not have any effect on propagation of scope data
        # scope data was always propagated no matter what the value of propagate_hub was
        # This is why the default for propagate_scope is True

        self.propagate_scope = propagate_scope

        if propagate_hub is not None:
            self.propagate_scope = propagate_hub

    @staticmethod
    def setup_once() -> None:
        old_start = Thread.start

        try:
            from django import VERSION as django_version  # noqa: N811
            import channels  # type: ignore[import-untyped]

            channels_version = channels.__version__
        except ImportError:
            django_version = None
            channels_version = None

        is_async_emulated_with_threads = (
            sys.version_info < (3, 9)
            and channels_version is not None
            and channels_version < "4.0.0"
            and django_version is not None
            and django_version >= (3, 0)
            and django_version < (4, 0)
        )

        @wraps(old_start)
        def sentry_start(self: "Thread", *a: "Any", **kw: "Any") -> "Any":
            integration = sentry_sdk.get_client().get_integration(ThreadingIntegration)
            if integration is None:
                return old_start(self, *a, **kw)

            if integration.propagate_scope:
                if is_async_emulated_with_threads:
                    warnings.warn(
                        "There is a known issue with Django channels 2.x and 3.x when using Python 3.8 or older. "
                        "(Async support is emulated using threads and some Sentry data may be leaked between those threads.) "
                        "Please either upgrade to Django channels 4.0+, use Django's async features "
                        "available in Django 3.1+ instead of Django channels, or upgrade to Python 3.9+.",
                        stacklevel=2,
                    )
                    isolation_scope = sentry_sdk.get_isolation_scope()
                    current_scope = sentry_sdk.get_current_scope()

                else:
                    isolation_scope = sentry_sdk.get_isolation_scope().fork()
                    current_scope = sentry_sdk.get_current_scope().fork()
            else:
                isolation_scope = None
                current_scope = None

            # Patching instance methods in `start()` creates a reference cycle if
            # done in a naive way. See
            # https://github.com/getsentry/sentry-python/pull/434
            #
            # In threading module, using current_thread API will access current thread instance
            # without holding it to avoid a reference cycle in an easier way.
            with capture_internal_exceptions():
                new_run = _wrap_run(
                    isolation_scope,
                    current_scope,
                    getattr(self.run, "__func__", self.run),
                )
                self.run = new_run  # type: ignore

            return old_start(self, *a, **kw)

        Thread.start = sentry_start  # type: ignore
        ThreadPoolExecutor.submit = _wrap_threadpool_executor_submit(  # type: ignore
            ThreadPoolExecutor.submit, is_async_emulated_with_threads
        )


def _wrap_run(
    isolation_scope_to_use: "Optional[sentry_sdk.Scope]",
    current_scope_to_use: "Optional[sentry_sdk.Scope]",
    old_run_func: "F",
) -> "F":
    @wraps(old_run_func)
    def run(*a: "Any", **kw: "Any") -> "Any":
        def _run_old_run_func() -> "Any":
            try:
                self = current_thread()
                return old_run_func(self, *a[1:], **kw)
            except Exception:
                reraise(*_capture_exception())

        if isolation_scope_to_use is not None and current_scope_to_use is not None:
            with use_isolation_scope(isolation_scope_to_use):
                with use_scope(current_scope_to_use):
                    return _run_old_run_func()
        else:
            return _run_old_run_func()

    return run  # type: ignore


def _wrap_threadpool_executor_submit(
    func: "Callable[..., Future[T]]", is_async_emulated_with_threads: bool
) -> "Callable[..., Future[T]]":
    """
    Wrap submit call to propagate scopes on task submission.
    """

    @wraps(func)
    def sentry_submit(
        self: "ThreadPoolExecutor",
        fn: "Callable[..., T]",
        *args: "Any",
        **kwargs: "Any",
    ) -> "Future[T]":
        integration = sentry_sdk.get_client().get_integration(ThreadingIntegration)
        if integration is None:
            return func(self, fn, *args, **kwargs)

        if integration.propagate_scope and is_async_emulated_with_threads:
            isolation_scope = sentry_sdk.get_isolation_scope()
            current_scope = sentry_sdk.get_current_scope()
        elif integration.propagate_scope:
            isolation_scope = sentry_sdk.get_isolation_scope().fork()
            current_scope = sentry_sdk.get_current_scope().fork()
        else:
            isolation_scope = None
            current_scope = None

        def wrapped_fn(*args: "Any", **kwargs: "Any") -> "Any":
            if isolation_scope is not None and current_scope is not None:
                with use_isolation_scope(isolation_scope):
                    with use_scope(current_scope):
                        return fn(*args, **kwargs)

            return fn(*args, **kwargs)

        return func(self, wrapped_fn, *args, **kwargs)

    return sentry_submit


def _capture_exception() -> "ExcInfo":
    exc_info = sys.exc_info()

    client = sentry_sdk.get_client()
    if client.get_integration(ThreadingIntegration) is not None:
        event, hint = event_from_exception(
            exc_info,
            client_options=client.options,
            mechanism={"type": "threading", "handled": False},
        )
        sentry_sdk.capture_event(event, hint=hint)

    return exc_info
