import sys
import time
from collections.abc import Generator
from datetime import datetime

from onyx.connectors.interfaces import BaseConnector
from onyx.connectors.interfaces import CheckpointConnector
from onyx.connectors.interfaces import CheckpointOutput
from onyx.connectors.interfaces import LoadConnector
from onyx.connectors.interfaces import PollConnector
from onyx.connectors.models import ConnectorCheckpoint
from onyx.connectors.models import ConnectorFailure
from onyx.connectors.models import Document
from onyx.utils.logger import setup_logger


logger = setup_logger()


TimeRange = tuple[datetime, datetime]


class CheckpointOutputWrapper:
    """
    Wraps a CheckpointOutput generator to give things back in a more digestible format.
    The connector format is easier for the connector implementor (e.g. it enforces exactly
    one new checkpoint is returned AND that the checkpoint is at the end), thus the different
    formats.
    """

    def __init__(self) -> None:
        self.next_checkpoint: ConnectorCheckpoint | None = None

    def __call__(
        self,
        checkpoint_connector_generator: CheckpointOutput,
    ) -> Generator[
        tuple[Document | None, ConnectorFailure | None, ConnectorCheckpoint | None],
        None,
        None,
    ]:
        # grabs the final return value and stores it in the `next_checkpoint` variable
        def _inner_wrapper(
            checkpoint_connector_generator: CheckpointOutput,
        ) -> CheckpointOutput:
            self.next_checkpoint = yield from checkpoint_connector_generator
            return self.next_checkpoint  # not used

        for document_or_failure in _inner_wrapper(checkpoint_connector_generator):
            if isinstance(document_or_failure, Document):
                yield document_or_failure, None, None
            elif isinstance(document_or_failure, ConnectorFailure):
                yield None, document_or_failure, None
            else:
                raise ValueError(
                    f"Invalid document_or_failure type: {type(document_or_failure)}"
                )

        if self.next_checkpoint is None:
            raise RuntimeError(
                "Checkpoint is None. This should never happen - the connector should always return a checkpoint."
            )

        yield None, None, self.next_checkpoint


class ConnectorRunner:
    """
    Handles:
        - Batching
        - Additional exception logging
        - Combining different connector types to a single interface
    """

    def __init__(
        self,
        connector: BaseConnector,
        batch_size: int,
        time_range: TimeRange | None = None,
    ):
        self.connector = connector
        self.time_range = time_range
        self.batch_size = batch_size

        self.doc_batch: list[Document] = []

    def run(
        self, checkpoint: ConnectorCheckpoint
    ) -> Generator[
        tuple[
            list[Document] | None, ConnectorFailure | None, ConnectorCheckpoint | None
        ],
        None,
        None,
    ]:
        """Adds additional exception logging to the connector."""
        try:
            if isinstance(self.connector, CheckpointConnector):
                if self.time_range is None:
                    raise ValueError("time_range is required for CheckpointConnector")

                start = time.monotonic()
                checkpoint_connector_generator = self.connector.load_from_checkpoint(
                    start=self.time_range[0].timestamp(),
                    end=self.time_range[1].timestamp(),
                    checkpoint=checkpoint,
                )
                next_checkpoint: ConnectorCheckpoint | None = None
                # this is guaranteed to always run at least once with next_checkpoint being non-None
                for document, failure, next_checkpoint in CheckpointOutputWrapper()(
                    checkpoint_connector_generator
                ):
                    if document is not None:
                        self.doc_batch.append(document)

                    if failure is not None:
                        yield None, failure, None

                    if len(self.doc_batch) >= self.batch_size:
                        yield self.doc_batch, None, None
                        self.doc_batch = []

                # yield remaining documents
                if len(self.doc_batch) > 0:
                    yield self.doc_batch, None, None
                    self.doc_batch = []

                yield None, None, next_checkpoint

                logger.debug(
                    f"Connector took {time.monotonic() - start} seconds to get to the next checkpoint."
                )

            else:
                finished_checkpoint = ConnectorCheckpoint.build_dummy_checkpoint()
                finished_checkpoint.has_more = False

                if isinstance(self.connector, PollConnector):
                    if self.time_range is None:
                        raise ValueError("time_range is required for PollConnector")

                    for document_batch in self.connector.poll_source(
                        start=self.time_range[0].timestamp(),
                        end=self.time_range[1].timestamp(),
                    ):
                        yield document_batch, None, None

                    yield None, None, finished_checkpoint
                elif isinstance(self.connector, LoadConnector):
                    for document_batch in self.connector.load_from_state():
                        yield document_batch, None, None

                    yield None, None, finished_checkpoint
                else:
                    raise ValueError(f"Invalid connector. type: {type(self.connector)}")
        except Exception:
            exc_type, _, exc_traceback = sys.exc_info()

            # Traverse the traceback to find the last frame where the exception was raised
            tb = exc_traceback
            if tb is None:
                logger.error("No traceback found for exception")
                raise

            while tb.tb_next:
                tb = tb.tb_next  # Move to the next frame in the traceback

            # Get the local variables from the frame where the exception occurred
            local_vars = tb.tb_frame.f_locals
            local_vars_str = "\n".join(
                f"{key}: {value}" for key, value in local_vars.items()
            )
            logger.error(
                f"Error in connector. type: {exc_type};\n"
                f"local_vars below -> \n{local_vars_str[:1024]}"
            )
            raise