from copy import copy
from collections import deque
from itertools import chain
import os
import uuid

from sentry_sdk.attachments import Attachment
from sentry_sdk._functools import wraps
from sentry_sdk.tracing_utils import (
    Baggage,
    extract_sentrytrace_data,
    has_tracing_enabled,
    normalize_incoming_data,
)
from sentry_sdk.tracing import (
    BAGGAGE_HEADER_NAME,
    SENTRY_TRACE_HEADER_NAME,
    Transaction,
)
from sentry_sdk._types import TYPE_CHECKING
from sentry_sdk.utils import logger, capture_internal_exceptions

from sentry_sdk.consts import FALSE_VALUES


if TYPE_CHECKING:
    from typing import Any
    from typing import Dict
    from typing import Iterator
    from typing import Optional
    from typing import Deque
    from typing import List
    from typing import Callable
    from typing import Tuple
    from typing import TypeVar

    from sentry_sdk._types import (
        Breadcrumb,
        Event,
        EventProcessor,
        ErrorProcessor,
        ExcInfo,
        Hint,
        Type,
    )

    from sentry_sdk.profiler import Profile
    from sentry_sdk.tracing import Span
    from sentry_sdk.session import Session

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


global_event_processors = []  # type: List[EventProcessor]


def add_global_event_processor(processor):
    # type: (EventProcessor) -> None
    global_event_processors.append(processor)


def _attr_setter(fn):
    # type: (Any) -> Any
    return property(fset=fn, doc=fn.__doc__)


def _disable_capture(fn):
    # type: (F) -> F
    @wraps(fn)
    def wrapper(self, *args, **kwargs):
        # type: (Any, *Dict[str, Any], **Any) -> Any
        if not self._should_capture:
            return
        try:
            self._should_capture = False
            return fn(self, *args, **kwargs)
        finally:
            self._should_capture = True

    return wrapper  # type: ignore


class Scope(object):
    """The scope holds extra information that should be sent with all
    events that belong to it.
    """

    # NOTE: Even though it should not happen, the scope needs to not crash when
    # accessed by multiple threads. It's fine if it's full of races, but those
    # races should never make the user application crash.
    #
    # The same needs to hold for any accesses of the scope the SDK makes.

    __slots__ = (
        "_level",
        "_name",
        "_fingerprint",
        # note that for legacy reasons, _transaction is the transaction *name*,
        # not a Transaction object (the object is stored in _span)
        "_transaction",
        "_transaction_info",
        "_user",
        "_tags",
        "_contexts",
        "_extras",
        "_breadcrumbs",
        "_event_processors",
        "_error_processors",
        "_should_capture",
        "_span",
        "_session",
        "_attachments",
        "_force_auto_session_tracking",
        "_profile",
        "_propagation_context",
    )

    def __init__(self):
        # type: () -> None
        self._event_processors = []  # type: List[EventProcessor]
        self._error_processors = []  # type: List[ErrorProcessor]

        self._name = None  # type: Optional[str]
        self._propagation_context = None  # type: Optional[Dict[str, Any]]

        self.clear()

        incoming_trace_information = self._load_trace_data_from_env()
        self.generate_propagation_context(incoming_data=incoming_trace_information)

    def _load_trace_data_from_env(self):
        # type: () -> Optional[Dict[str, str]]
        """
        Load Sentry trace id and baggage from environment variables.
        Can be disabled by setting SENTRY_USE_ENVIRONMENT to "false".
        """
        incoming_trace_information = None

        sentry_use_environment = (
            os.environ.get("SENTRY_USE_ENVIRONMENT") or ""
        ).lower()
        use_environment = sentry_use_environment not in FALSE_VALUES
        if use_environment:
            incoming_trace_information = {}

            if os.environ.get("SENTRY_TRACE"):
                incoming_trace_information[SENTRY_TRACE_HEADER_NAME] = (
                    os.environ.get("SENTRY_TRACE") or ""
                )

            if os.environ.get("SENTRY_BAGGAGE"):
                incoming_trace_information[BAGGAGE_HEADER_NAME] = (
                    os.environ.get("SENTRY_BAGGAGE") or ""
                )

        return incoming_trace_information or None

    def _extract_propagation_context(self, data):
        # type: (Dict[str, Any]) -> Optional[Dict[str, Any]]
        context = {}  # type: Dict[str, Any]
        normalized_data = normalize_incoming_data(data)

        baggage_header = normalized_data.get(BAGGAGE_HEADER_NAME)
        if baggage_header:
            context["dynamic_sampling_context"] = Baggage.from_incoming_header(
                baggage_header
            ).dynamic_sampling_context()

        sentry_trace_header = normalized_data.get(SENTRY_TRACE_HEADER_NAME)
        if sentry_trace_header:
            sentrytrace_data = extract_sentrytrace_data(sentry_trace_header)
            if sentrytrace_data is not None:
                context.update(sentrytrace_data)

        only_baggage_no_sentry_trace = (
            "dynamic_sampling_context" in context and "trace_id" not in context
        )
        if only_baggage_no_sentry_trace:
            context.update(self._create_new_propagation_context())

        if context:
            if not context.get("span_id"):
                context["span_id"] = uuid.uuid4().hex[16:]

            return context

        return None

    def _create_new_propagation_context(self):
        # type: () -> Dict[str, Any]
        return {
            "trace_id": uuid.uuid4().hex,
            "span_id": uuid.uuid4().hex[16:],
            "parent_span_id": None,
            "dynamic_sampling_context": None,
        }

    def set_new_propagation_context(self):
        # type: () -> None
        """
        Creates a new propagation context and sets it as `_propagation_context`. Overwriting existing one.
        """
        self._propagation_context = self._create_new_propagation_context()
        logger.debug(
            "[Tracing] Create new propagation context: %s",
            self._propagation_context,
        )

    def generate_propagation_context(self, incoming_data=None):
        # type: (Optional[Dict[str, str]]) -> None
        """
        Makes sure `_propagation_context` is set.
        If there is `incoming_data` overwrite existing `_propagation_context`.
        if there is no `incoming_data` create new `_propagation_context`, but do NOT overwrite if already existing.
        """
        if incoming_data:
            context = self._extract_propagation_context(incoming_data)

            if context is not None:
                self._propagation_context = context
                logger.debug(
                    "[Tracing] Extracted propagation context from incoming data: %s",
                    self._propagation_context,
                )

        if self._propagation_context is None:
            self.set_new_propagation_context()

    def get_dynamic_sampling_context(self):
        # type: () -> Optional[Dict[str, str]]
        """
        Returns the Dynamic Sampling Context from the Propagation Context.
        If not existing, creates a new one.
        """
        if self._propagation_context is None:
            return None

        baggage = self.get_baggage()
        if baggage is not None:
            self._propagation_context[
                "dynamic_sampling_context"
            ] = baggage.dynamic_sampling_context()

        return self._propagation_context["dynamic_sampling_context"]

    def get_traceparent(self):
        # type: () -> Optional[str]
        """
        Returns the Sentry "sentry-trace" header (aka the traceparent) from the Propagation Context.
        """
        if self._propagation_context is None:
            return None

        traceparent = "%s-%s" % (
            self._propagation_context["trace_id"],
            self._propagation_context["span_id"],
        )
        return traceparent

    def get_baggage(self):
        # type: () -> Optional[Baggage]
        if self._propagation_context is None:
            return None

        dynamic_sampling_context = self._propagation_context.get(
            "dynamic_sampling_context"
        )
        if dynamic_sampling_context is None:
            return Baggage.from_options(self)
        else:
            return Baggage(dynamic_sampling_context)

    def get_trace_context(self):
        # type: () -> Any
        """
        Returns the Sentry "trace" context from the Propagation Context.
        """
        if self._propagation_context is None:
            return None

        trace_context = {
            "trace_id": self._propagation_context["trace_id"],
            "span_id": self._propagation_context["span_id"],
            "parent_span_id": self._propagation_context["parent_span_id"],
            "dynamic_sampling_context": self.get_dynamic_sampling_context(),
        }  # type: Dict[str, Any]

        return trace_context

    def iter_headers(self):
        # type: () -> Iterator[Tuple[str, str]]
        """
        Creates a generator which returns the `sentry-trace` and `baggage` headers from the Propagation Context.
        """
        if self._propagation_context is not None:
            traceparent = self.get_traceparent()
            if traceparent is not None:
                yield SENTRY_TRACE_HEADER_NAME, traceparent

            dsc = self.get_dynamic_sampling_context()
            if dsc is not None:
                baggage = Baggage(dsc).serialize()
                yield BAGGAGE_HEADER_NAME, baggage

    def clear(self):
        # type: () -> None
        """Clears the entire scope."""
        self._level = None  # type: Optional[str]
        self._fingerprint = None  # type: Optional[List[str]]
        self._transaction = None  # type: Optional[str]
        self._transaction_info = {}  # type: Dict[str, str]
        self._user = None  # type: Optional[Dict[str, Any]]

        self._tags = {}  # type: Dict[str, Any]
        self._contexts = {}  # type: Dict[str, Dict[str, Any]]
        self._extras = {}  # type: Dict[str, Any]
        self._attachments = []  # type: List[Attachment]

        self.clear_breadcrumbs()
        self._should_capture = True

        self._span = None  # type: Optional[Span]
        self._session = None  # type: Optional[Session]
        self._force_auto_session_tracking = None  # type: Optional[bool]

        self._profile = None  # type: Optional[Profile]

        self._propagation_context = None

    @_attr_setter
    def level(self, value):
        # type: (Optional[str]) -> None
        """When set this overrides the level. Deprecated in favor of set_level."""
        self._level = value

    def set_level(self, value):
        # type: (Optional[str]) -> None
        """Sets the level for the scope."""
        self._level = value

    @_attr_setter
    def fingerprint(self, value):
        # type: (Optional[List[str]]) -> None
        """When set this overrides the default fingerprint."""
        self._fingerprint = value

    @property
    def transaction(self):
        # type: () -> Any
        # would be type: () -> Optional[Transaction], see https://github.com/python/mypy/issues/3004
        """Return the transaction (root span) in the scope, if any."""

        # there is no span/transaction on the scope
        if self._span is None:
            return None

        # there is an orphan span on the scope
        if self._span.containing_transaction is None:
            return None

        # there is either a transaction (which is its own containing
        # transaction) or a non-orphan span on the scope
        return self._span.containing_transaction

    @transaction.setter
    def transaction(self, value):
        # type: (Any) -> None
        # would be type: (Optional[str]) -> None, see https://github.com/python/mypy/issues/3004
        """When set this forces a specific transaction name to be set.

        Deprecated: use set_transaction_name instead."""

        # XXX: the docstring above is misleading. The implementation of
        # apply_to_event prefers an existing value of event.transaction over
        # anything set in the scope.
        # XXX: note that with the introduction of the Scope.transaction getter,
        # there is a semantic and type mismatch between getter and setter. The
        # getter returns a Transaction, the setter sets a transaction name.
        # Without breaking version compatibility, we could make the setter set a
        # transaction name or transaction (self._span) depending on the type of
        # the value argument.

        logger.warning(
            "Assigning to scope.transaction directly is deprecated: use scope.set_transaction_name() instead."
        )
        self._transaction = value
        if self._span and self._span.containing_transaction:
            self._span.containing_transaction.name = value

    def set_transaction_name(self, name, source=None):
        # type: (str, Optional[str]) -> None
        """Set the transaction name and optionally the transaction source."""
        self._transaction = name

        if self._span and self._span.containing_transaction:
            self._span.containing_transaction.name = name
            if source:
                self._span.containing_transaction.source = source

        if source:
            self._transaction_info["source"] = source

    @_attr_setter
    def user(self, value):
        # type: (Optional[Dict[str, Any]]) -> None
        """When set a specific user is bound to the scope. Deprecated in favor of set_user."""
        self.set_user(value)

    def set_user(self, value):
        # type: (Optional[Dict[str, Any]]) -> None
        """Sets a user for the scope."""
        self._user = value
        if self._session is not None:
            self._session.update(user=value)

    @property
    def span(self):
        # type: () -> Optional[Span]
        """Get/set current tracing span or transaction."""
        return self._span

    @span.setter
    def span(self, span):
        # type: (Optional[Span]) -> None
        self._span = span
        # XXX: this differs from the implementation in JS, there Scope.setSpan
        # does not set Scope._transactionName.
        if isinstance(span, Transaction):
            transaction = span
            if transaction.name:
                self._transaction = transaction.name

    @property
    def profile(self):
        # type: () -> Optional[Profile]
        return self._profile

    @profile.setter
    def profile(self, profile):
        # type: (Optional[Profile]) -> None

        self._profile = profile

    def set_tag(
        self,
        key,  # type: str
        value,  # type: Any
    ):
        # type: (...) -> None
        """Sets a tag for a key to a specific value."""
        self._tags[key] = value

    def remove_tag(
        self, key  # type: str
    ):
        # type: (...) -> None
        """Removes a specific tag."""
        self._tags.pop(key, None)

    def set_context(
        self,
        key,  # type: str
        value,  # type: Dict[str, Any]
    ):
        # type: (...) -> None
        """Binds a context at a certain key to a specific value."""
        self._contexts[key] = value

    def remove_context(
        self, key  # type: str
    ):
        # type: (...) -> None
        """Removes a context."""
        self._contexts.pop(key, None)

    def set_extra(
        self,
        key,  # type: str
        value,  # type: Any
    ):
        # type: (...) -> None
        """Sets an extra key to a specific value."""
        self._extras[key] = value

    def remove_extra(
        self, key  # type: str
    ):
        # type: (...) -> None
        """Removes a specific extra key."""
        self._extras.pop(key, None)

    def clear_breadcrumbs(self):
        # type: () -> None
        """Clears breadcrumb buffer."""
        self._breadcrumbs = deque()  # type: Deque[Breadcrumb]

    def add_attachment(
        self,
        bytes=None,  # type: Optional[bytes]
        filename=None,  # type: Optional[str]
        path=None,  # type: Optional[str]
        content_type=None,  # type: Optional[str]
        add_to_transactions=False,  # type: bool
    ):
        # type: (...) -> None
        """Adds an attachment to future events sent."""
        self._attachments.append(
            Attachment(
                bytes=bytes,
                path=path,
                filename=filename,
                content_type=content_type,
                add_to_transactions=add_to_transactions,
            )
        )

    def add_event_processor(
        self, func  # type: EventProcessor
    ):
        # type: (...) -> None
        """Register a scope local event processor on the scope.

        :param func: This function behaves like `before_send.`
        """
        if len(self._event_processors) > 20:
            logger.warning(
                "Too many event processors on scope! Clearing list to free up some memory: %r",
                self._event_processors,
            )
            del self._event_processors[:]

        self._event_processors.append(func)

    def add_error_processor(
        self,
        func,  # type: ErrorProcessor
        cls=None,  # type: Optional[Type[BaseException]]
    ):
        # type: (...) -> None
        """Register a scope local error processor on the scope.

        :param func: A callback that works similar to an event processor but is invoked with the original exception info triple as second argument.

        :param cls: Optionally, only process exceptions of this type.
        """
        if cls is not None:
            cls_ = cls  # For mypy.
            real_func = func

            def func(event, exc_info):
                # type: (Event, ExcInfo) -> Optional[Event]
                try:
                    is_inst = isinstance(exc_info[1], cls_)
                except Exception:
                    is_inst = False
                if is_inst:
                    return real_func(event, exc_info)
                return event

        self._error_processors.append(func)

    @_disable_capture
    def apply_to_event(
        self,
        event,  # type: Event
        hint,  # type: Hint
        options=None,  # type: Optional[Dict[str, Any]]
    ):
        # type: (...) -> Optional[Event]
        """Applies the information contained on the scope to the given event."""

        def _drop(cause, ty):
            # type: (Any, str) -> Optional[Any]
            logger.info("%s (%s) dropped event", ty, cause)
            return None

        is_transaction = event.get("type") == "transaction"

        # put all attachments into the hint. This lets callbacks play around
        # with attachments. We also later pull this out of the hint when we
        # create the envelope.
        attachments_to_send = hint.get("attachments") or []
        for attachment in self._attachments:
            if not is_transaction or attachment.add_to_transactions:
                attachments_to_send.append(attachment)
        hint["attachments"] = attachments_to_send

        if self._level is not None:
            event["level"] = self._level

        if not is_transaction:
            event.setdefault("breadcrumbs", {}).setdefault("values", []).extend(
                self._breadcrumbs
            )

        if event.get("user") is None and self._user is not None:
            event["user"] = self._user

        if event.get("transaction") is None and self._transaction is not None:
            event["transaction"] = self._transaction

        if event.get("transaction_info") is None and self._transaction_info is not None:
            event["transaction_info"] = self._transaction_info

        if event.get("fingerprint") is None and self._fingerprint is not None:
            event["fingerprint"] = self._fingerprint

        if self._extras:
            event.setdefault("extra", {}).update(self._extras)

        if self._tags:
            event.setdefault("tags", {}).update(self._tags)

        if self._contexts:
            event.setdefault("contexts", {}).update(self._contexts)

        contexts = event.setdefault("contexts", {})

        if contexts.get("trace") is None:
            if has_tracing_enabled(options) and self._span is not None:
                contexts["trace"] = self._span.get_trace_context()
            else:
                contexts["trace"] = self.get_trace_context()

        try:
            replay_id = contexts["trace"]["dynamic_sampling_context"]["replay_id"]
        except (KeyError, TypeError):
            replay_id = None

        if replay_id is not None:
            contexts["replay"] = {
                "replay_id": replay_id,
            }

        exc_info = hint.get("exc_info")
        if exc_info is not None:
            for error_processor in self._error_processors:
                new_event = error_processor(event, exc_info)
                if new_event is None:
                    return _drop(error_processor, "error processor")
                event = new_event

        for event_processor in chain(global_event_processors, self._event_processors):
            new_event = event
            with capture_internal_exceptions():
                new_event = event_processor(event, hint)
            if new_event is None:
                return _drop(event_processor, "event processor")
            event = new_event

        return event

    def update_from_scope(self, scope):
        # type: (Scope) -> None
        """Update the scope with another scope's data."""
        if scope._level is not None:
            self._level = scope._level
        if scope._fingerprint is not None:
            self._fingerprint = scope._fingerprint
        if scope._transaction is not None:
            self._transaction = scope._transaction
        if scope._transaction_info is not None:
            self._transaction_info.update(scope._transaction_info)
        if scope._user is not None:
            self._user = scope._user
        if scope._tags:
            self._tags.update(scope._tags)
        if scope._contexts:
            self._contexts.update(scope._contexts)
        if scope._extras:
            self._extras.update(scope._extras)
        if scope._breadcrumbs:
            self._breadcrumbs.extend(scope._breadcrumbs)
        if scope._span:
            self._span = scope._span
        if scope._attachments:
            self._attachments.extend(scope._attachments)
        if scope._profile:
            self._profile = scope._profile
        if scope._propagation_context:
            self._propagation_context = scope._propagation_context

    def update_from_kwargs(
        self,
        user=None,  # type: Optional[Any]
        level=None,  # type: Optional[str]
        extras=None,  # type: Optional[Dict[str, Any]]
        contexts=None,  # type: Optional[Dict[str, Any]]
        tags=None,  # type: Optional[Dict[str, str]]
        fingerprint=None,  # type: Optional[List[str]]
    ):
        # type: (...) -> None
        """Update the scope's attributes."""
        if level is not None:
            self._level = level
        if user is not None:
            self._user = user
        if extras is not None:
            self._extras.update(extras)
        if contexts is not None:
            self._contexts.update(contexts)
        if tags is not None:
            self._tags.update(tags)
        if fingerprint is not None:
            self._fingerprint = fingerprint

    def __copy__(self):
        # type: () -> Scope
        rv = object.__new__(self.__class__)  # type: Scope

        rv._level = self._level
        rv._name = self._name
        rv._fingerprint = self._fingerprint
        rv._transaction = self._transaction
        rv._transaction_info = dict(self._transaction_info)
        rv._user = self._user

        rv._tags = dict(self._tags)
        rv._contexts = dict(self._contexts)
        rv._extras = dict(self._extras)

        rv._breadcrumbs = copy(self._breadcrumbs)
        rv._event_processors = list(self._event_processors)
        rv._error_processors = list(self._error_processors)
        rv._propagation_context = self._propagation_context

        rv._should_capture = self._should_capture
        rv._span = self._span
        rv._session = self._session
        rv._force_auto_session_tracking = self._force_auto_session_tracking
        rv._attachments = list(self._attachments)

        rv._profile = self._profile

        return rv

    def __repr__(self):
        # type: () -> str
        return "<%s id=%s name=%s>" % (
            self.__class__.__name__,
            hex(id(self)),
            self._name,
        )
