"""Interface definitions"""
import abc
import uuid
from abc import ABC, abstractmethod
from enum import IntEnum, IntFlag, auto
from types import TracebackType
from typing import Any, Dict, Generator, TypeVar, Generic, Callable, TypeAlias
from collections.abc import Iterator
from anthropic import BaseModel

from common.data_source.models import (
    Document,
    KeyRecord,
    SlimDocument,
    ConnectorCheckpoint,
    ConnectorFailure,
    SecondsSinceUnixEpoch, GenerateSlimDocumentOutput
)


class IncrementalCapability(IntEnum):
    """How a connector handles incremental sync.

    FULL_RESYNC  -- every sync re-pulls; no per-key state.
    CURSOR       -- "give me everything since cursor X"; opaque cursor persisted across syncs.
    FINGERPRINT  -- list_keys() returns (key, fingerprint) cheaply; bodies fetched lazily.
    """
    FULL_RESYNC = 0
    CURSOR = 1
    FINGERPRINT = 2


GenerateDocumentsOutput = Iterator[list[Document]]

class LoadConnector(ABC):
    """Load connector interface"""

    @abstractmethod
    def load_credentials(self, credentials: Dict[str, Any]) -> Dict[str, Any] | None:
        """Load credentials"""
        pass

    @abstractmethod
    def load_from_state(self) -> Generator[list[Document], None, None]:
        """Load documents from state"""
        pass

    def validate_connector_settings(self) -> None:
        """Validate connector settings"""
        pass


class PollConnector(ABC):
    """Poll connector interface"""

    @abstractmethod
    def poll_source(self, start: SecondsSinceUnixEpoch, end: SecondsSinceUnixEpoch) -> Generator[list[Document], None, None]:
        """Poll source to get documents"""
        pass


class CredentialsConnector(ABC):
    """Credentials connector interface"""

    @abstractmethod
    def load_credentials(self, credentials: Dict[str, Any]) -> Dict[str, Any] | None:
        """Load credentials"""
        pass


class SlimConnectorWithPermSync(ABC):
    """Simplified connector interface (with permission sync)"""

    @abstractmethod
    def retrieve_all_slim_docs_perm_sync(
        self,
        callback: Any = None,
    ) -> Generator[list[SlimDocument], None, None]:
        """Retrieve all simplified documents (with permission sync)"""
        pass


class CheckpointedConnectorWithPermSync(ABC):
    """Checkpoint connector interface (with permission sync)"""

    @abstractmethod
    def load_from_checkpoint(
        self,
        start: SecondsSinceUnixEpoch,
        end: SecondsSinceUnixEpoch,
        checkpoint: ConnectorCheckpoint,
    ) -> Generator[Document | ConnectorFailure, None, ConnectorCheckpoint]:
        """Load documents from checkpoint"""
        pass

    @abstractmethod
    def load_from_checkpoint_with_perm_sync(
        self,
        start: SecondsSinceUnixEpoch,
        end: SecondsSinceUnixEpoch,
        checkpoint: ConnectorCheckpoint,
    ) -> Generator[Document | ConnectorFailure, None, ConnectorCheckpoint]:
        """Load documents from checkpoint (with permission sync)"""
        pass

    @abstractmethod
    def build_dummy_checkpoint(self) -> ConnectorCheckpoint:
        """Build dummy checkpoint"""
        pass

    @abstractmethod
    def validate_checkpoint_json(self, checkpoint_json: str) -> ConnectorCheckpoint:
        """Validate checkpoint JSON"""
        pass


T = TypeVar("T", bound="CredentialsProviderInterface")


class CredentialsProviderInterface(abc.ABC, Generic[T]):
    @abc.abstractmethod
    def __enter__(self) -> T:
        raise NotImplementedError

    @abc.abstractmethod
    def __exit__(
        self,
        exc_type: type[BaseException] | None,
        exc_value: BaseException | None,
        traceback: TracebackType | None,
    ) -> None:
        raise NotImplementedError

    @abc.abstractmethod
    def get_tenant_id(self) -> str | None:
        raise NotImplementedError

    @abc.abstractmethod
    def get_provider_key(self) -> str:
        """a unique key that the connector can use to lock around a credential
        that might be used simultaneously.

        Will typically be the credential id, but can also just be something random
        in cases when there is nothing to lock (aka static credentials)
        """
        raise NotImplementedError

    @abc.abstractmethod
    def get_credentials(self) -> dict[str, Any]:
        raise NotImplementedError

    @abc.abstractmethod
    def set_credentials(self, credential_json: dict[str, Any]) -> None:
        raise NotImplementedError

    @abc.abstractmethod
    def is_dynamic(self) -> bool:
        """If dynamic, the credentials may change during usage ... meaning the client
        needs to use the locking features of the credentials provider to operate
        correctly.

        If static, the client can simply reference the credentials once and use them
        through the entire indexing run.
        """
        raise NotImplementedError


class StaticCredentialsProvider(
    CredentialsProviderInterface["StaticCredentialsProvider"]
):
    """Implementation (a very simple one!) to handle static credentials."""

    def __init__(
        self,
        tenant_id: str | None,
        connector_name: str,
        credential_json: dict[str, Any],
    ):
        self._tenant_id = tenant_id
        self._connector_name = connector_name
        self._credential_json = credential_json

        self._provider_key = str(uuid.uuid4())

    def __enter__(self) -> "StaticCredentialsProvider":
        return self

    def __exit__(
        self,
        exc_type: type[BaseException] | None,
        exc_value: BaseException | None,
        traceback: TracebackType | None,
    ) -> None:
        pass

    def get_tenant_id(self) -> str | None:
        return self._tenant_id

    def get_provider_key(self) -> str:
        return self._provider_key

    def get_credentials(self) -> dict[str, Any]:
        return self._credential_json

    def set_credentials(self, credential_json: dict[str, Any]) -> None:
        self._credential_json = credential_json

    def is_dynamic(self) -> bool:
        return False


CT = TypeVar("CT", bound=ConnectorCheckpoint)


class BaseConnector(abc.ABC, Generic[CT]):
    REDIS_KEY_PREFIX = "da_connector_data:"
    # Common image file extensions supported across connectors
    IMAGE_EXTENSIONS = {".jpg", ".jpeg", ".png", ".webp", ".gif"}

    @abc.abstractmethod
    def load_credentials(self, credentials: dict[str, Any]) -> dict[str, Any] | None:
        raise NotImplementedError

    @staticmethod
    def parse_metadata(metadata: dict[str, Any]) -> list[str]:
        """Parse the metadata for a document/chunk into a string to pass to Generative AI as additional context"""
        custom_parser_req_msg = (
            "Specific metadata parsing required, connector has not implemented it."
        )
        metadata_lines = []
        for metadata_key, metadata_value in metadata.items():
            if isinstance(metadata_value, str):
                metadata_lines.append(f"{metadata_key}: {metadata_value}")
            elif isinstance(metadata_value, list):
                if not all([isinstance(val, str) for val in metadata_value]):
                    raise RuntimeError(custom_parser_req_msg)
                metadata_lines.append(f'{metadata_key}: {", ".join(metadata_value)}')
            else:
                raise RuntimeError(custom_parser_req_msg)
        return metadata_lines

    def validate_connector_settings(self) -> None:
        """
        Override this if your connector needs to validate credentials or settings.
        Raise an exception if invalid, otherwise do nothing.

        Default is a no-op (always successful).
        """

    def validate_perm_sync(self) -> None:
        """
        Permission-sync validation hook.

        RAGFlow doesn't ship the Onyx EE permission-sync validation package.
        Connectors that support permission sync should override
        `validate_connector_settings()` as needed.
        """
        return None

    def set_allow_images(self, value: bool) -> None:
        """Implement if the underlying connector wants to skip/allow image downloading
        based on the application level image analysis setting."""

    def build_dummy_checkpoint(self) -> CT:
        # TODO: find a way to make this work without type: ignore
        return ConnectorCheckpoint(has_more=True)  # type: ignore


CheckpointOutput: TypeAlias = Generator[Document | ConnectorFailure, None, CT]
LoadFunction = Callable[[CT], CheckpointOutput[CT]]


class CheckpointedConnector(BaseConnector[CT]):
    @abc.abstractmethod
    def load_from_checkpoint(
        self,
        start: SecondsSinceUnixEpoch,
        end: SecondsSinceUnixEpoch,
        checkpoint: CT,
    ) -> CheckpointOutput[CT]:
        """Yields back documents or failures. Final return is the new checkpoint.

        Final return can be access via either:

        ```
        try:
            for document_or_failure in connector.load_from_checkpoint(start, end, checkpoint):
                print(document_or_failure)
        except StopIteration as e:
            checkpoint = e.value  # Extracting the return value
            print(checkpoint)
        ```

        OR

        ```
        checkpoint = yield from connector.load_from_checkpoint(start, end, checkpoint)
        ```
        """
        raise NotImplementedError

    @abc.abstractmethod
    def build_dummy_checkpoint(self) -> CT:
        raise NotImplementedError

    @abc.abstractmethod
    def validate_checkpoint_json(self, checkpoint_json: str) -> CT:
        """Validate the checkpoint json and return the checkpoint object"""
        raise NotImplementedError


class CheckpointOutputWrapper(Generic[CT]):
    """
    Wraps a CheckpointOutput generator to give things back in a more digestible format,
    specifically for Document outputs.
    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: CT | None = None

    def __call__(
        self,
        checkpoint_connector_generator: CheckpointOutput[CT],
    ) -> Generator[
        tuple[Document | None, ConnectorFailure | None, CT | None],
        None,
        None,
    ]:
        # grabs the final return value and stores it in the `next_checkpoint` variable
        def _inner_wrapper(
            checkpoint_connector_generator: CheckpointOutput[CT],
        ) -> CheckpointOutput[CT]:
            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 CheckpointedConnectorWithPermSyncGH(CheckpointedConnector[CT]):
    @abc.abstractmethod
    def load_from_checkpoint_with_perm_sync(
        self,
        start: SecondsSinceUnixEpoch,
        end: SecondsSinceUnixEpoch,
        checkpoint: CT,
    ) -> CheckpointOutput[CT]:
        raise NotImplementedError


# Slim connectors retrieve just the ids of documents
class SlimConnector(BaseConnector):
    @abc.abstractmethod
    def retrieve_all_slim_docs(
        self,
    ) -> GenerateSlimDocumentOutput:
        raise NotImplementedError


class ConfluenceUser(BaseModel):
    user_id: str  # accountId in Cloud, userKey in Server
    username: str | None  # Confluence Cloud doesn't give usernames
    display_name: str
    # Confluence Data Center doesn't give email back by default,
    # have to fetch it with a different endpoint
    email: str | None
    type: str


class TokenResponse(BaseModel):
    access_token: str
    expires_in: int
    token_type: str
    refresh_token: str
    scope: str


class OnyxExtensionType(IntFlag):
    Plain = auto()
    Document = auto()
    Multimedia = auto()
    All = Plain | Document | Multimedia


class AttachmentProcessingResult(BaseModel):
    """
    A container for results after processing a Confluence attachment.
    'text' is the textual content of the attachment.
    'file_name' is the final file name used in FileStore to store the content.
    'error' holds an exception or string if something failed.
    """

    text: str | None
    file_blob: bytes | bytearray | None
    file_name: str | None
    error: str | None = None

    model_config = {"arbitrary_types_allowed": True}


class IndexingHeartbeatInterface(ABC):
    """Defines a callback interface to be passed to run_indexing_entrypoint."""

    @abstractmethod
    def should_stop(self) -> bool:
        """Signal to stop the looping function in flight."""

    @abstractmethod
    def progress(self, tag: str, amount: int) -> None:
        """Send progress updates to the caller.
        Amount can be a positive number to indicate progress or <= 0
        just to act as a keep-alive.
        """


class FingerprintConnector(ABC):
    """Tier 1 connector: cheap full listing with per-key fingerprint.

    Sources that can enumerate their entire keyspace via a metadata-only call
    (e.g. S3 list_objects_v2 returning ETag + LastModified) implement this to
    let the orchestrator skip GetObject for keys whose fingerprint hasn't
    changed since the last sync.

    The fingerprint is an opaque equality token: two equal fingerprints mean
    the content is unchanged from the orchestrator's point of view. Format is
    a 32-char hex string so it fits the existing Document.content_hash column;
    connectors are responsible for normalizing whatever the source exposes
    (typically by hashing it with xxhash128).
    """

    INCREMENTAL_CAPABILITY: IncrementalCapability = IncrementalCapability.FINGERPRINT

    @abstractmethod
    def list_keys(self) -> Iterator[KeyRecord]:
        """Yield one KeyRecord per object currently in the source.

        Must enumerate the full current keyspace -- the orchestrator diffs the
        result against persisted state to detect adds, updates, and deletes.
        """
        raise NotImplementedError

    @abstractmethod
    def get_value(self, key: str) -> Document:
        """Fetch the body for a single key, returning a fully populated Document.

        Called only when list_keys()'s fingerprint differs from the persisted
        content_hash for that key (or when no persisted fingerprint exists).
        """
        raise NotImplementedError

