# Copyright The OpenTelemetry Authors
# SPDX-License-Identifier: Apache-2.0

"""OTLP Exporter

This module provides a mixin class for OTLP exporters that send telemetry data
to an OTLP-compatible receiver via gRPC. It includes a configurable reconnection
logic to handle transient collector outages.

"""

import os
import random
import threading
from abc import ABC, abstractmethod
from collections.abc import (
    Callable,
    Iterable,
    Sequence,  # noqa: F401
)
from collections.abc import Sequence as TypingSequence
from logging import getLogger
from os import environ
from time import time
from typing import (  # noqa: F401
    Any,
    Generic,
    Literal,
    NewType,
    Optional,
    TypeVar,
)
from urllib.parse import urlparse

from google.rpc.error_details_pb2 import RetryInfo
from typing_extensions import deprecated

from grpc import (
    ChannelCredentials,
    Compression,
    RpcError,
    StatusCode,
    insecure_channel,
    secure_channel,
    ssl_channel_credentials,
)
from opentelemetry.exporter.otlp.proto.common._exporter_metrics import (
    create_exporter_metrics,
)
from opentelemetry.exporter.otlp.proto.common._internal import (
    _get_resource_data,
)
from opentelemetry.exporter.otlp.proto.grpc import (
    _OTLP_GRPC_CHANNEL_OPTIONS,
)
from opentelemetry.metrics import MeterProvider
from opentelemetry.proto.collector.logs.v1.logs_service_pb2 import (
    ExportLogsServiceRequest,
)
from opentelemetry.proto.collector.logs.v1.logs_service_pb2_grpc import (
    LogsServiceStub,
)
from opentelemetry.proto.collector.metrics.v1.metrics_service_pb2 import (
    ExportMetricsServiceRequest,
)
from opentelemetry.proto.collector.metrics.v1.metrics_service_pb2_grpc import (
    MetricsServiceStub,
)
from opentelemetry.proto.collector.trace.v1.trace_service_pb2 import (
    ExportTraceServiceRequest,
)
from opentelemetry.proto.collector.trace.v1.trace_service_pb2_grpc import (
    TraceServiceStub,
)
from opentelemetry.proto.common.v1.common_pb2 import (  # noqa: F401
    AnyValue,
    ArrayValue,
    KeyValue,
)
from opentelemetry.proto.resource.v1.resource_pb2 import Resource  # noqa: F401
from opentelemetry.sdk._logs import ReadableLogRecord
from opentelemetry.sdk._logs.export import LogRecordExportResult
from opentelemetry.sdk._shared_internal import DuplicateFilter
from opentelemetry.sdk.environment_variables import (
    _OTEL_PYTHON_EXPORTER_OTLP_GRPC_CREDENTIAL_PROVIDER,
    _OTEL_PYTHON_EXPORTER_OTLP_GRPC_RETRYABLE_ERROR_CODES,
    OTEL_EXPORTER_OTLP_CERTIFICATE,
    OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE,
    OTEL_EXPORTER_OTLP_CLIENT_KEY,
    OTEL_EXPORTER_OTLP_COMPRESSION,
    OTEL_EXPORTER_OTLP_ENDPOINT,
    OTEL_EXPORTER_OTLP_HEADERS,
    OTEL_EXPORTER_OTLP_INSECURE,
    OTEL_EXPORTER_OTLP_TIMEOUT,
    OTEL_PYTHON_SDK_INTERNAL_METRICS_ENABLED,
)
from opentelemetry.sdk.metrics.export import MetricExportResult, MetricsData
from opentelemetry.sdk.resources import Resource as SDKResource
from opentelemetry.sdk.trace import ReadableSpan
from opentelemetry.sdk.trace.export import SpanExportResult
from opentelemetry.semconv._incubating.attributes.otel_attributes import (
    OtelComponentTypeValues,
)
from opentelemetry.semconv._incubating.attributes.rpc_attributes import (
    RPC_RESPONSE_STATUS_CODE,
)
from opentelemetry.util._importlib_metadata import entry_points
from opentelemetry.util.re import parse_env_headers

_RETRYABLE_ERROR_CODES = frozenset(
    [
        StatusCode.CANCELLED,
        StatusCode.DEADLINE_EXCEEDED,
        StatusCode.RESOURCE_EXHAUSTED,
        StatusCode.ABORTED,
        StatusCode.OUT_OF_RANGE,
        StatusCode.UNAVAILABLE,
        StatusCode.DATA_LOSS,
    ]
)
_MAX_RETRYS = 6
logger = getLogger(__name__)
# This prevents logs generated when a log fails to be written to generate another log which fails to be written etc. etc.
logger.addFilter(DuplicateFilter())
SDKDataT = TypeVar(
    "SDKDataT",
    TypingSequence[ReadableLogRecord],
    MetricsData,
    TypingSequence[ReadableSpan],
)
ResourceDataT = TypeVar("ResourceDataT")
TypingResourceT = TypeVar("TypingResourceT")
ExportServiceRequestT = TypeVar(
    "ExportServiceRequestT",
    ExportTraceServiceRequest,
    ExportMetricsServiceRequest,
    ExportLogsServiceRequest,
)
ExportResultT = TypeVar(
    "ExportResultT",
    LogRecordExportResult,
    MetricExportResult,
    SpanExportResult,
)
ExportStubT = TypeVar("ExportStubT", TraceServiceStub, MetricsServiceStub, LogsServiceStub)

_ENVIRON_TO_COMPRESSION = {
    None: None,
    "gzip": Compression.Gzip,
}


class InvalidCompressionValueException(Exception):
    def __init__(self, environ_key: str, environ_value: str):
        super().__init__(f'Invalid value "{environ_value}" for compression envvar {environ_key}')


def environ_to_compression(environ_key: str) -> Compression | None:
    environ_value = environ[environ_key].lower().strip() if environ_key in environ else None
    if environ_value not in _ENVIRON_TO_COMPRESSION and environ_value is not None:
        raise InvalidCompressionValueException(environ_key, environ_value)
    return _ENVIRON_TO_COMPRESSION[environ_value]


@deprecated(
    "Use one of the encoders from opentelemetry-exporter-otlp-proto-common instead. Deprecated since version 1.18.0.",
)
def get_resource_data(
    sdk_resource_scope_data: dict[SDKResource, ResourceDataT],
    resource_class: Callable[..., TypingResourceT],
    name: str,
) -> list[TypingResourceT]:
    return _get_resource_data(sdk_resource_scope_data, resource_class, name)


def _read_file(file_path: str) -> bytes | None:
    try:
        with open(file_path, "rb") as file:
            return file.read()
    except FileNotFoundError as e:
        logger.exception(
            "Failed to read file: %s. Please check if the file exists and is accessible.",
            e.filename,
        )
        return None


def _load_credentials(
    certificate_file: str | None,
    client_key_file: str | None,
    client_certificate_file: str | None,
) -> ChannelCredentials:
    root_certificates = _read_file(certificate_file) if certificate_file else None
    private_key = _read_file(client_key_file) if client_key_file else None
    certificate_chain = _read_file(client_certificate_file) if client_certificate_file else None

    return ssl_channel_credentials(
        root_certificates=root_certificates,
        private_key=private_key,
        certificate_chain=certificate_chain,
    )


def _get_credentials(
    creds: ChannelCredentials | None,
    credential_entry_point_env_key: str,
    certificate_file_env_key: str,
    client_key_file_env_key: str,
    client_certificate_file_env_key: str,
) -> ChannelCredentials:
    if creds is not None:
        return creds
    _credential_env = environ.get(credential_entry_point_env_key)
    if _credential_env:
        try:
            maybe_channel_creds = next(
                iter(
                    entry_points(
                        group="opentelemetry_otlp_credential_provider",
                        name=_credential_env,
                    )
                )
            ).load()()
        except StopIteration:
            raise RuntimeError(
                f"Requested component '{_credential_env}' not found in "
                f"entry point 'opentelemetry_otlp_credential_provider'"
            )
        if isinstance(maybe_channel_creds, ChannelCredentials):
            return maybe_channel_creds
        else:
            raise RuntimeError(
                f"Requested component '{_credential_env}' is of type {type(maybe_channel_creds)}"
                f" must be of type `grpc.ChannelCredentials`."
            )

    certificate_file = environ.get(certificate_file_env_key)
    if certificate_file:
        client_key_file = environ.get(client_key_file_env_key)
        client_certificate_file = environ.get(client_certificate_file_env_key)
        credentials = _load_credentials(certificate_file, client_key_file, client_certificate_file)
        if credentials is not None:
            return credentials
    return ssl_channel_credentials()


# pylint: disable=no-member
class OTLPExporterMixin(ABC, Generic[SDKDataT, ExportServiceRequestT, ExportResultT, ExportStubT]):
    """OTLP gRPC exporter mixin.

    This class provides the base functionality for OTLP exporters that send
    telemetry data (spans or metrics) to an OTLP-compatible receiver via gRPC.
    It includes a configurable reconnection mechanism to handle transient
    receiver outages.

    Args:
        endpoint: OTLP-compatible receiver endpoint
        insecure: Connection type
        credentials: ChannelCredentials object for server authentication
        headers: Headers to send when exporting
        timeout: Backend request timeout in seconds
        compression: gRPC compression method to use
        channel_options: gRPC channel options
    """

    def __init__(
        self,
        stub: ExportStubT,
        result: ExportResultT,
        endpoint: str | None = None,
        insecure: bool | None = None,
        credentials: ChannelCredentials | None = None,
        headers: TypingSequence[tuple[str, str]] | dict[str, str] | str | None = None,
        timeout: float | None = None,
        compression: Compression | None = None,
        channel_options: tuple[tuple[str, str]] | None = None,
        retryable_error_codes: Iterable[StatusCode] | None = None,
        *,
        component_type: OtelComponentTypeValues | None = None,
        signal: Literal["traces", "metrics", "logs"] = "traces",
        meter_provider: MeterProvider | None = None,
    ):
        super().__init__()
        self._result = result
        self._stub = stub
        self._endpoint = endpoint or environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, "http://localhost:4317")

        parsed_url = urlparse(self._endpoint)

        if parsed_url.scheme == "https":
            insecure = False
        insecure_exporter = environ.get(OTEL_EXPORTER_OTLP_INSECURE)
        if insecure is None:
            if insecure_exporter is not None:
                insecure = insecure_exporter.lower() == "true"
            else:
                insecure = parsed_url.scheme == "http"

        if parsed_url.netloc:
            self._endpoint = parsed_url.netloc

        self._insecure = insecure
        self._credentials = credentials
        self._headers = headers or environ.get(OTEL_EXPORTER_OTLP_HEADERS)
        if isinstance(self._headers, str):
            temp_headers = parse_env_headers(self._headers, liberal=True)
            self._headers = tuple(temp_headers.items())
        elif isinstance(self._headers, dict):
            self._headers = tuple(self._headers.items())
        if self._headers is None:
            self._headers = tuple()

        if channel_options:
            # merge the default channel options with the one passed as parameter
            overridden_options = {opt_name for (opt_name, _) in channel_options}
            default_options = tuple(
                (opt_name, opt_value)
                for opt_name, opt_value in _OTLP_GRPC_CHANNEL_OPTIONS
                if opt_name not in overridden_options
            )
            self._channel_options = default_options + channel_options
        else:
            self._channel_options = tuple(_OTLP_GRPC_CHANNEL_OPTIONS)

        self._timeout = timeout or float(environ.get(OTEL_EXPORTER_OTLP_TIMEOUT, 10))
        self._collector_kwargs = None

        self._compression = (
            environ_to_compression(OTEL_EXPORTER_OTLP_COMPRESSION) if compression is None else compression
        ) or Compression.NoCompression

        self._retryable_error_codes = retryable_error_codes or os.environ.get(
            _OTEL_PYTHON_EXPORTER_OTLP_GRPC_RETRYABLE_ERROR_CODES
        )
        if isinstance(self._retryable_error_codes, str):
            self._retryable_error_codes = frozenset(
                StatusCode[code.strip().upper()] for code in self._retryable_error_codes.split(",") if code.strip()
            )
        elif self._retryable_error_codes is not None:
            self._retryable_error_codes = frozenset(self._retryable_error_codes)
        else:
            self._retryable_error_codes = _RETRYABLE_ERROR_CODES

        self._channel = None
        self._client = None

        self._shutdown_in_progress = threading.Event()
        self._shutdown = False

        if not self._insecure:
            self._credentials = _get_credentials(
                self._credentials,
                _OTEL_PYTHON_EXPORTER_OTLP_GRPC_CREDENTIAL_PROVIDER,
                OTEL_EXPORTER_OTLP_CERTIFICATE,
                OTEL_EXPORTER_OTLP_CLIENT_KEY,
                OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE,
            )

        self._component_type = component_type
        self._signal: Literal["traces", "metrics", "logs"] = signal
        self._parsed_url = parsed_url
        self._metrics = create_exporter_metrics(
            self._component_type,
            signal,
            parsed_url,
            meter_provider,
            os.environ.get(OTEL_PYTHON_SDK_INTERNAL_METRICS_ENABLED, "").strip().lower() == "true",
        )

        self._initialize_channel_and_stub()

    def _initialize_channel_and_stub(self):
        """
        Create a new gRPC channel and stub.

        This method is used during initialization and by the reconnection
        mechanism to reinitialize the channel on transient errors.
        """
        if self._insecure:
            self._channel = insecure_channel(
                self._endpoint,
                compression=self._compression,
                options=self._channel_options,
            )
        else:
            assert self._credentials is not None
            self._channel = secure_channel(
                self._endpoint,
                self._credentials,
                compression=self._compression,
                options=self._channel_options,
            )
        self._client = self._stub(self._channel)  # type: ignore [reportCallIssue]

    @abstractmethod
    def _translate_data(
        self,
        data: SDKDataT,
    ) -> ExportServiceRequestT:
        pass

    @abstractmethod
    def _count_data(
        self,
        data: SDKDataT,
    ) -> int:
        pass

    def _export(
        self,
        data: SDKDataT,
    ) -> ExportResultT:
        if self._shutdown:
            logger.warning("Exporter already shutdown, ignoring batch")
            return self._result.FAILURE  # type: ignore [reportReturnType]

        with self._metrics.export_operation(self._count_data(data)) as result:
            # FIXME remove this check if the export type for traces
            # gets updated to a class that represents the proto
            # TracesData and use the code below instead.
            deadline_sec = time() + self._timeout
            for retry_num in range(_MAX_RETRYS):
                try:
                    if self._client is None:
                        return self._result.FAILURE
                    self._client.Export(
                        request=self._translate_data(data),
                        metadata=self._headers,
                        timeout=deadline_sec - time(),
                    )
                    return self._result.SUCCESS  # type: ignore [reportReturnType]
                except RpcError as error:
                    retry_info_bin = dict(error.trailing_metadata()).get(  # type: ignore [reportAttributeAccessIssue]
                        "google.rpc.retryinfo-bin"  # type: ignore [reportArgumentType]
                    )
                    # multiplying by a random number between .8 and 1.2 introduces a +/20% jitter to each backoff.
                    backoff_seconds = 2**retry_num * random.uniform(0.8, 1.2)
                    if retry_info_bin is not None:
                        retry_info = RetryInfo()
                        retry_info.ParseFromString(retry_info_bin)
                        backoff_seconds = retry_info.retry_delay.seconds + retry_info.retry_delay.nanos / 1.0e9

                    # For UNAVAILABLE errors, reinitialize the channel to force reconnection
                    if error.code() == StatusCode.UNAVAILABLE and retry_num == 0:  # type: ignore
                        logger.debug(
                            "Reinitializing gRPC channel for %s exporter due to UNAVAILABLE error",
                            self._exporting,
                        )
                        try:
                            if self._channel:
                                self._channel.close()
                        except Exception as e:
                            logger.debug(
                                "Error closing channel for %s exporter to %s: %s",
                                self._exporting,
                                self._endpoint,
                                str(e),
                            )
                        # Enable channel reconnection for subsequent calls
                        self._initialize_channel_and_stub()

                    if (
                        error.code() not in self._retryable_error_codes  # type: ignore [reportAttributeAccessIssue]
                        or retry_num + 1 == _MAX_RETRYS
                        or backoff_seconds > (deadline_sec - time())
                        or self._shutdown
                    ):
                        logger.error(
                            "Failed to export %s to %s, error code: %s, error details: %s",
                            self._exporting,
                            self._endpoint,
                            error.code(),  # type: ignore [reportAttributeAccessIssue]
                            error.details(),
                            exc_info=error.code() == StatusCode.UNKNOWN,  # type: ignore [reportAttributeAccessIssue]
                        )
                        result.error = error
                        result.error_attrs = {RPC_RESPONSE_STATUS_CODE: error.code().name}
                        return self._result.FAILURE  # type: ignore [reportReturnType]
                    logger.warning(
                        "Transient error %s encountered while exporting %s to %s, retrying in %.2fs. Error details: %s",
                        error.code(),  # type: ignore [reportAttributeAccessIssue]
                        self._exporting,
                        self._endpoint,
                        backoff_seconds,
                        error.details(),
                    )
                shutdown = self._shutdown_in_progress.wait(backoff_seconds)
                if shutdown:
                    logger.warning("Shutdown in progress, aborting retry.")
                    break
            # Not possible to reach here but the linter is complaining.
            return self._result.FAILURE  # type: ignore [reportReturnType]

    def shutdown(self, timeout_millis: float = 30_000, **kwargs) -> None:
        """
        Shut down the exporter.

        Args:
            timeout_millis: Timeout in milliseconds for shutting down the exporter.
        """
        if self._shutdown:
            logger.warning("Exporter already shutdown, ignoring call")
            return
        self._shutdown = True
        self._shutdown_in_progress.set()
        if self._channel:
            self._channel.close()

    @property
    @abstractmethod
    def _exporting(self) -> str:
        """
        Returns a string that describes the overall exporter, to be used in
        warning messages.
        """
        pass

    def _set_meter_provider(self, meter_provider: MeterProvider) -> None:
        self._metrics = create_exporter_metrics(
            self._component_type,
            self._signal,
            self._parsed_url,
            meter_provider,
            os.environ.get(OTEL_PYTHON_SDK_INTERNAL_METRICS_ENABLED, "").strip().lower() == "true",
        )
