# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project

from vllm.distributed.weight_transfer.base import (
    WeightTransferInitRequest,
    WeightTransferUpdateRequest,
)
from vllm.entrypoints.common.offline import OfflineInferenceMixin


class RLOfflineMixin(OfflineInferenceMixin):
    def init_weight_transfer_engine(
        self, request: WeightTransferInitRequest | dict
    ) -> None:
        """Initialize weight transfer for RL training.

        Args:
            request: Weight transfer initialization request with backend-specific info

        """
        init_info_dict = (
            request["init_info"] if isinstance(request, dict) else request.init_info
        )

        self.llm_engine.collective_rpc(
            "init_weight_transfer_engine", kwargs={"init_info": init_info_dict}
        )

    def shutdown_weight_transfer_engine(self) -> None:
        """Release the trainer connection without shutting down inference."""
        self.llm_engine.collective_rpc("shutdown_weight_transfer_engine")

    def start_weight_update(self) -> None:
        """Start a new weight update."""
        self.llm_engine.collective_rpc("start_weight_update")

    def start_draft_weight_update(self) -> None:
        """Start a new weight update targeting the speculative draft model."""
        self.llm_engine.collective_rpc("start_draft_weight_update")

    def update_weights(self, request: WeightTransferUpdateRequest | dict) -> None:
        """Update the weights of the model.

        Args:
            request: Weight update request with backend-specific update info

        """
        update_info_dict = (
            request["update_info"] if isinstance(request, dict) else request.update_info
        )

        self.llm_engine.collective_rpc(
            "update_weights", kwargs={"update_info": update_info_dict}
        )

    def finish_weight_update(self, weight_version: str | None = None) -> None:
        """Finish the weight update and set its version if provided."""
        self.llm_engine.collective_rpc("finish_weight_update")
        if weight_version is not None:
            self.llm_engine.set_weight_version(weight_version)

    def update_weight_version(self, new_version: str) -> None:
        """Set the weight version without updating weights."""
        self.llm_engine.set_weight_version(new_version)

    def get_weight_version(self) -> str:
        """Return the latest committed weight version."""
        return self.llm_engine.get_weight_version()