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

import argparse
import contextlib
import contextvars
import dataclasses
import json
import os
import tempfile
import threading
import time
from collections.abc import Generator, MutableMapping
from dataclasses import asdict, dataclass, field, fields
from typing import TYPE_CHECKING, Any, ClassVar

import regex as re
import torch
from huggingface_hub import snapshot_download
from torch import nn
from torch.utils._python_dispatch import TorchDispatchMode
from transformers import PretrainedConfig

import vllm.envs as envs
from vllm.config import ModelConfig, ParallelConfig, VllmConfig, set_current_vllm_config
from vllm.logger import init_logger
from vllm.model_executor.layers.vocab_parallel_embedding import VocabParallelEmbedding
from vllm.platforms import current_platform
from vllm.utils.argparse_utils import FlexibleArgumentParser
from vllm.utils.import_utils import PlaceholderModule

if TYPE_CHECKING:
    from vllm.engine.arg_utils import EngineArgs

try:
    from tensorizer import (
        DecryptionParams,
        EncryptionParams,
        TensorDeserializer,
        TensorSerializer,
    )
    from tensorizer.stream_io import open_stream
    from tensorizer.utils import convert_bytes, get_mem_usage, no_init_or_tensor

except ImportError:
    tensorizer = PlaceholderModule("tensorizer")
    DecryptionParams = tensorizer.placeholder_attr("DecryptionParams")
    EncryptionParams = tensorizer.placeholder_attr("EncryptionParams")
    TensorDeserializer = tensorizer.placeholder_attr("TensorDeserializer")
    TensorSerializer = tensorizer.placeholder_attr("TensorSerializer")
    open_stream = tensorizer.placeholder_attr("stream_io.open_stream")
    convert_bytes = tensorizer.placeholder_attr("utils.convert_bytes")
    get_mem_usage = tensorizer.placeholder_attr("utils.get_mem_usage")
    no_init_or_tensor = tensorizer.placeholder_attr("utils.no_init_or_tensor")

__all__ = [
    "EncryptionParams",
    "DecryptionParams",
    "TensorDeserializer",
    "TensorSerializer",
    "open_stream",
    "convert_bytes",
    "get_mem_usage",
    "no_init_or_tensor",
    "TensorizerConfig",
]

logger = init_logger(__name__)


def is_valid_deserialization_uri(uri: str | None) -> bool:
    if uri:
        scheme = uri.lower().split("://")[0]
        return scheme in {"s3", "http", "https"} or os.path.exists(uri)
    return False


def tensorizer_kwargs_arg(value):
    loaded = json.loads(value)
    if not isinstance(loaded, dict):
        raise argparse.ArgumentTypeError(
            f"Not deserializable to dict: {value}. serialization_kwargs and "
            f"deserialization_kwargs must be "
            f"deserializable from a JSON string to a dictionary. "
        )
    return loaded


class MetaTensorMode(TorchDispatchMode):
    def __torch_dispatch__(self, func, types, args=(), kwargs=None):
        kwargs = kwargs or {}

        if func._schema.name == "aten::empty" and "device" not in kwargs:
            kwargs["device"] = "meta"

        return func(*args, **kwargs)


def meta_tensor_mode(
    loading_code=None,
):
    if loading_code is None:
        return _NoInitOrTensorImpl.context_manager()
    elif callable(loading_code):
        with _NoInitOrTensorImpl.context_manager():
            return loading_code()
    else:
        raise TypeError(
            "expected a callable to evaluate,"
            " or None if being used as a context manager;"
            f' got an object of type "{type(loading_code).__name__}" instead.'
        )


class _NoInitOrTensorImpl:
    _MODULES = (torch.nn.Linear, torch.nn.Embedding, torch.nn.LayerNorm)
    _MODULE_ORIGINALS = tuple((m, m.reset_parameters) for m in _MODULES)

    is_active = contextvars.ContextVar("_NoInitOrTensorImpl.is_active", default=False)
    _count_active: int = 0
    _count_active_lock = threading.Lock()

    @classmethod
    @contextlib.contextmanager
    def context_manager(cls):
        if cls.is_active.get():
            yield
            return

        with cls._count_active_lock:
            cls._count_active += 1
            if cls._count_active == 1:
                for mod in cls._MODULES:
                    mod.reset_parameters = cls._disable(mod.reset_parameters)

        reset_token = cls.is_active.set(True)

        try:
            with MetaTensorMode():
                yield
        finally:
            cls.is_active.reset(reset_token)
            with cls._count_active_lock:
                cls._count_active -= 1
                if cls._count_active == 0:
                    for mod, original in cls._MODULE_ORIGINALS:
                        mod.reset_parameters = original

    @staticmethod
    def _disable(func):
        def wrapper(*args, **kwargs):
            if not _NoInitOrTensorImpl.is_active.get():
                return func(*args, **kwargs)

        return wrapper


@dataclass
class TensorizerConfig(MutableMapping):
    tensorizer_uri: str | None = None
    tensorizer_dir: str | None = None
    vllm_tensorized: bool | None = None
    verify_hash: bool | None = None
    num_readers: int | None = None
    encryption_keyfile: str | None = None
    s3_access_key_id: str | None = None
    s3_secret_access_key: str | None = None
    s3_endpoint: str | None = None
    lora_dir: str | None = None
    stream_kwargs: dict[str, Any] | None = None
    serialization_kwargs: dict[str, Any] | None = None
    deserialization_kwargs: dict[str, Any] | None = None
    _extra_serialization_attrs: dict[str, Any] | None = field(init=False, default=None)
    model_class: type[torch.nn.Module] | None = field(init=False, default=None)
    hf_config: PretrainedConfig | None = field(init=False, default=None)
    dtype: str | torch.dtype | None = field(init=False, default=None)
    _is_sharded: bool = field(init=False, default=False)
    _fields: ClassVar[tuple[str, ...]]
    _keys: ClassVar[frozenset[str]]
    """Configuration class for Tensorizer settings.
    
    These settings configure the behavior of model serialization and 
    deserialization using Tensorizer.
    
    Attributes:
        tensorizer_uri: Path to serialized model tensors. Can be a local file 
            path or a S3 URI. This is a required field unless lora_dir is 
            provided and the config is meant to be used for the
            `tensorize_lora_adapter` function. Unless a `tensorizer_dir` or 
            `lora_dir` is passed to this object's initializer, this is 
            a required argument.
        tensorizer_dir: Path to a directory containing serialized model tensors,
            and all other potential model artifacts to load the model, such as 
            configs and tokenizer files. Can be passed instead of 
            `tensorizer_uri` where the `model.tensors` file will be assumed 
            to be in this directory.
        vllm_tensorized: If True, indicates that the serialized model is a 
            vLLM model. This is used to determine the behavior of the 
            TensorDeserializer when loading tensors from a serialized model.
            It is far faster to deserialize a vLLM model as it utilizes
            tensorizer's optimized GPU loading. Note that this is now
            deprecated, as serialized vLLM models are now automatically
            inferred as vLLM models.
        verify_hash: If True, the hashes of each tensor will be verified 
            against the hashes stored in the metadata. A `HashMismatchError` 
            will be raised if any of the hashes do not match.
        num_readers: Controls how many threads are allowed to read concurrently
            from the source file. Default is `None`, which will dynamically set
            the number of readers based on the number of available 
            resources and model size. This greatly increases performance.
        encryption_keyfile: File path to a binary file containing a  
            binary key to use for decryption. `None` (the default) means 
            no decryption. See the example script in 
            examples/others/tensorize_vllm_model.py. 
        s3_access_key_id: The access key for the S3 bucket. Can also be set via
            the S3_ACCESS_KEY_ID environment variable.
        s3_secret_access_key: The secret access key for the S3 bucket. Can also
            be set via the S3_SECRET_ACCESS_KEY environment variable.
        s3_endpoint: The endpoint for the S3 bucket. Can also be set via the
            S3_ENDPOINT_URL environment variable.
        lora_dir: Path to a directory containing LoRA adapter artifacts for 
            serialization or deserialization. When serializing LoRA adapters 
            this is the only necessary parameter to pass to this object's 
            initializer.
    """

    def __post_init__(self):
        # check if the configuration is for a sharded vLLM model
        self._is_sharded = (
            isinstance(self.tensorizer_uri, str)
            and re.search(r"%0\dd", self.tensorizer_uri) is not None
        )

        if self.tensorizer_dir and self.lora_dir:
            raise ValueError(
                "Only one of tensorizer_dir or lora_dir may be specified. "
                "Use lora_dir exclusively when serializing LoRA adapters, "
                "and tensorizer_dir or tensorizer_uri otherwise."
            )
        if self.tensorizer_dir and self.tensorizer_uri:
            logger.warning_once(
                "Provided both tensorizer_dir and tensorizer_uri. "
                "Inferring tensorizer_dir from tensorizer_uri as the "
                "latter takes precedence."
            )
            self.tensorizer_dir = os.path.dirname(self.tensorizer_uri)
        if not self.tensorizer_uri:
            if self.lora_dir:
                self.tensorizer_uri = f"{self.lora_dir}/adapter_model.tensors"
            elif self.tensorizer_dir:
                self.tensorizer_uri = f"{self.tensorizer_dir}/model.tensors"
            else:
                raise ValueError(
                    "Unable to resolve tensorizer_uri. "
                    "A valid tensorizer_uri or tensorizer_dir "
                    "must be provided for deserialization, and a "
                    "valid tensorizer_uri, tensorizer_uri, or "
                    "lora_dir for serialization."
                )
        else:
            self.tensorizer_dir = os.path.dirname(self.tensorizer_uri)

        if not self.serialization_kwargs:
            self.serialization_kwargs = {}
        if not self.deserialization_kwargs:
            self.deserialization_kwargs = {}

    def to_serializable(self) -> dict[str, Any]:
        # Due to TensorizerConfig needing to be msgpack-serializable, it needs
        # support for morphing back and forth between itself and its dict
        # representation

        # TensorizerConfig's representation as a dictionary is meant to be
        # linked to TensorizerConfig in such a way that the following is
        # technically initializable:
        # TensorizerConfig(**my_tensorizer_cfg.to_serializable())

        # This means the dict must not retain non-initializable parameters
        # and post-init attribute states

        # Also don't want to retain private and unset parameters, so only retain
        # not None values and public attributes

        raw_tc_dict = asdict(self)
        blacklisted = []

        if "tensorizer_uri" in raw_tc_dict and "tensorizer_dir" in raw_tc_dict:
            blacklisted.append("tensorizer_dir")

        if "tensorizer_dir" in raw_tc_dict and "lora_dir" in raw_tc_dict:
            blacklisted.append("tensorizer_dir")

        tc_dict = {}
        for k, v in raw_tc_dict.items():
            if (
                k not in blacklisted
                and k not in tc_dict
                and not k.startswith("_")
                and v is not None
            ):
                tc_dict[k] = v

        return tc_dict

    def _construct_tensorizer_args(self) -> "TensorizerArgs":
        return TensorizerArgs(self)  # type: ignore

    def verify_with_parallel_config(
        self,
        parallel_config: "ParallelConfig",
    ) -> None:
        if parallel_config.tensor_parallel_size > 1 and not self._is_sharded:
            raise ValueError(
                "For a sharded model, tensorizer_uri should include a"
                " string format template like '%04d' to be formatted"
                " with the rank of the shard"
            )

    def verify_with_model_config(self, model_config: "ModelConfig") -> None:
        if model_config.quantization is not None and self.tensorizer_uri is not None:
            logger.warning(
                "Loading a model using Tensorizer with quantization on vLLM"
                " is unstable and may lead to errors."
            )

    def open_stream(self, tensorizer_args: "TensorizerArgs | None" = None):
        if tensorizer_args is None:
            tensorizer_args = self._construct_tensorizer_args()

        return open_stream(self.tensorizer_uri, **tensorizer_args.stream_kwargs)

    def keys(self):
        return self._keys

    def __len__(self):
        return len(fields(self))

    def __iter__(self):
        return iter(self._fields)

    def __getitem__(self, item: str) -> Any:
        if item not in self.keys():
            raise KeyError(item)
        return getattr(self, item)

    def __setitem__(self, key: str, value: Any) -> None:
        if key not in self.keys():
            # Disallow modifying invalid keys
            raise KeyError(key)
        setattr(self, key, value)

    def __delitem__(self, key, /):
        if key not in self.keys():
            raise KeyError(key)
        delattr(self, key)


TensorizerConfig._fields = tuple(f.name for f in fields(TensorizerConfig))
TensorizerConfig._keys = frozenset(TensorizerConfig._fields)


@dataclass
class TensorizerArgs:
    tensorizer_uri: str | None = None
    tensorizer_dir: str | None = None
    encryption_keyfile: str | None = None

    def __init__(self, tensorizer_config: TensorizerConfig):
        for k, v in tensorizer_config.items():
            setattr(self, k, v)
        self.file_obj = tensorizer_config.tensorizer_uri
        self.s3_access_key_id = (
            tensorizer_config.s3_access_key_id or envs.S3_ACCESS_KEY_ID
        )
        self.s3_secret_access_key = (
            tensorizer_config.s3_secret_access_key or envs.S3_SECRET_ACCESS_KEY
        )
        self.s3_endpoint = tensorizer_config.s3_endpoint or envs.S3_ENDPOINT_URL

        self.stream_kwargs = {
            "s3_access_key_id": tensorizer_config.s3_access_key_id,
            "s3_secret_access_key": tensorizer_config.s3_secret_access_key,
            "s3_endpoint": tensorizer_config.s3_endpoint,
            **(tensorizer_config.stream_kwargs or {}),
        }

        self.deserialization_kwargs = {
            "verify_hash": tensorizer_config.verify_hash,
            "encryption": tensorizer_config.encryption_keyfile,
            "num_readers": tensorizer_config.num_readers,
            **(tensorizer_config.deserialization_kwargs or {}),
        }

        if self.encryption_keyfile:
            with open_stream(
                tensorizer_config.encryption_keyfile,
                **self.stream_kwargs,
            ) as stream:
                key = stream.read()
                decryption_params = DecryptionParams.from_key(key)
                self.deserialization_kwargs["encryption"] = decryption_params

    @staticmethod
    def add_cli_args(parser: FlexibleArgumentParser) -> FlexibleArgumentParser:
        """Tensorizer CLI arguments"""

        # Tensorizer options arg group
        group = parser.add_argument_group(
            "tensorizer options",
            description=(
                "Options for configuring the behavior of the"
                " tensorizer deserializer when "
                "load_format=tensorizer is specified when "
                "initializing an LLMEngine, either via the CLI "
                "when running the vLLM OpenAI inference server "
                "with a JSON string passed to "
                "--model-loader-extra-config or as arguments given "
                "to TensorizerConfig when passed to "
                "model_loader_extra_config in the constructor "
                "for LLMEngine."
            ),
        )

        group.add_argument(
            "--tensorizer-uri",
            type=str,
            help="Path to serialized model tensors. Can be a local file path,"
            " or an HTTP(S) or S3 URI.",
        )
        group.add_argument(
            "--verify-hash",
            action="store_true",
            help="If enabled, the hashes of each tensor will be verified"
            " against the hashes stored in the file metadata. An exception"
            " will be raised if any of the hashes do not match.",
        )
        group.add_argument(
            "--encryption-keyfile",
            type=str,
            default=None,
            help="The file path to a binary file containing a binary key to "
            "use for decryption. Can be a file path or S3 network URI.",
        )
        group.add_argument(
            "--num-readers",
            default=None,
            type=int,
            help="Controls how many threads are allowed to read concurrently "
            "from the source file. Default is `None`, which will dynamically "
            "set the number of readers based on the available resources "
            "and model size. This greatly increases performance.",
        )
        group.add_argument(
            "--s3-access-key-id",
            type=str,
            default=None,
            help="The access key for the S3 bucket. Can also be set via the "
            "S3_ACCESS_KEY_ID environment variable.",
        )
        group.add_argument(
            "--s3-secret-access-key",
            type=str,
            default=None,
            help="The secret access key for the S3 bucket. Can also be set via "
            "the S3_SECRET_ACCESS_KEY environment variable.",
        )
        group.add_argument(
            "--s3-endpoint",
            type=str,
            default=None,
            help="The endpoint for the S3 bucket. Can also be set via the "
            "S3_ENDPOINT_URL environment variable.",
        )

        return parser

    @classmethod
    def from_cli_args(cls, args: argparse.Namespace) -> "TensorizerArgs":
        attrs = [attr.name for attr in dataclasses.fields(cls)]
        tensorizer_args = cls(
            **{attr: getattr(args, attr) for attr in attrs if hasattr(args, attr)}
        )
        return tensorizer_args


def _check_tensors_on_meta_device(model: nn.Module) -> None:
    for tensor in model.state_dict().values():
        if tensor.device.type == "meta":
            raise ValueError(
                "The serialized model contains tensors on the meta device,"
                " indicating that some tensors were not loaded properly."
                " Please check that the parameters of the model being"
                " specified match that of the serialized model, such as"
                " its quantization."
            )


def _resize_lora_embeddings(model: nn.Module):
    """Modify LoRA embedding layers to use bigger tensors
    to allow for adapter added tokens."""
    for child in model.modules():
        if (
            isinstance(child, VocabParallelEmbedding)
            and child.weight.shape[0] < child.num_embeddings_per_partition
        ):
            new_weight = torch.empty(
                child.num_embeddings_per_partition,
                child.embedding_dim,
                dtype=child.weight.dtype,
                device=child.weight.device,
            )
            new_weight[: child.weight.shape[0]].copy_(child.weight.data)
            new_weight[child.weight.shape[0] :].fill_(0)
            child.weight.data = new_weight


def init_tensorizer_model(
    tensorizer_config: TensorizerConfig, vllm_config: VllmConfig
) -> nn.Module:
    assert tensorizer_config.hf_config is not None
    model_args = tensorizer_config.hf_config
    model_args.dtype = tensorizer_config.dtype
    assert tensorizer_config.model_class is not None
    # TODO: Do we need to consider old-style model class?
    with meta_tensor_mode(), set_current_vllm_config(vllm_config, check_compile=True):
        return tensorizer_config.model_class(vllm_config=vllm_config)


def deserialize_tensorizer_model(
    model: nn.Module, tensorizer_config: TensorizerConfig
) -> None:
    tensorizer_args = tensorizer_config._construct_tensorizer_args()
    if not is_valid_deserialization_uri(tensorizer_config.tensorizer_uri):
        raise ValueError(
            f"{tensorizer_config.tensorizer_uri} is not a valid "
            f"tensorizer URI. Please check that the URI is correct. "
            f"It must either point to a local existing file, or have a "
            f"S3, HTTP or HTTPS scheme."
        )
    before_mem = get_mem_usage()
    start = time.perf_counter()
    device_index = torch.accelerator.current_device_index()
    device_type = current_platform.device_type
    with (
        open_stream(
            tensorizer_config.tensorizer_uri, mode="rb", **tensorizer_args.stream_kwargs
        ) as stream,
        TensorDeserializer(
            stream,
            dtype=tensorizer_config.dtype,
            device=f"{device_type}:{device_index}",
            **tensorizer_args.deserialization_kwargs,
        ) as deserializer,
    ):
        deserializer.load_into_module(model)
        end = time.perf_counter()

    total_bytes_str = convert_bytes(deserializer.total_tensor_bytes)
    duration = end - start
    per_second = convert_bytes(deserializer.total_tensor_bytes / duration)
    after_mem = get_mem_usage()
    deserializer.close()
    logger.info(
        "Deserialized %s in %0.2fs, %s/s", total_bytes_str, end - start, per_second
    )
    logger.info("Memory usage before: %s", before_mem)
    logger.info("Memory usage after: %s", after_mem)

    _check_tensors_on_meta_device(model)
    _resize_lora_embeddings(model)
    del model.vllm_tensorized_marker


def tensorizer_weights_iterator(
    tensorizer_args: "TensorizerArgs",
) -> Generator[tuple[str, torch.Tensor], None, None]:
    logger.warning(
        "Deserializing HuggingFace models is not optimized for "
        "loading on vLLM, as tensorizer is forced to load to CPU. "
        "Consider deserializing a vLLM model instead for faster "
        "load times. See the "
        "examples/others/tensorize_vllm_model.py example script "
        "for serializing vLLM models."
    )

    deserializer_args = tensorizer_args.deserialization_kwargs
    stream_kwargs = tensorizer_args.stream_kwargs
    stream = open_stream(tensorizer_args.tensorizer_uri, **stream_kwargs)
    with TensorDeserializer(stream, **deserializer_args, device="cpu") as state:
        yield from state.items()
    del state


def is_vllm_tensorized(tensorizer_config: "TensorizerConfig") -> bool:
    """
    Infer if the model is a vLLM model by checking the weights for
    a vLLM tensorized marker.

    Args:
        tensorizer_config: The TensorizerConfig object containing the
            tensorizer_uri to the serialized model.

    Returns:
        bool: True if the model is a vLLM model, False otherwise.
    """
    tensorizer_args = tensorizer_config._construct_tensorizer_args()
    deserializer = TensorDeserializer(
        open_stream(tensorizer_args.tensorizer_uri, **tensorizer_args.stream_kwargs),
        **tensorizer_args.deserialization_kwargs,
        lazy_load=True,
    )
    if tensorizer_config.vllm_tensorized:
        logger.warning(
            "Please note that newly serialized vLLM models are automatically "
            "inferred as vLLM models, so setting vllm_tensorized=True is "
            "only necessary for models serialized prior to this change."
        )
        return True
    return ".vllm_tensorized_marker" in deserializer


def serialize_extra_artifacts(
    tensorizer_args: TensorizerArgs, served_model_name: str | list[str] | None
) -> None:
    if not isinstance(served_model_name, str):
        raise ValueError(
            f"served_model_name must be a str for serialize_extra_artifacts, "
            f"not {type(served_model_name)}."
        )

    with tempfile.TemporaryDirectory() as tmpdir:
        snapshot_download(
            served_model_name,
            local_dir=tmpdir,
            ignore_patterns=[
                "*.pt",
                "*.safetensors",
                "*.bin",
                "*.cache",
                "*.gitattributes",
                "*.md",
            ],
        )
        for artifact in os.scandir(tmpdir):
            if not artifact.is_file():
                continue
            with (
                open(artifact.path, "rb") as f,
                open_stream(
                    f"{tensorizer_args.tensorizer_dir}/{artifact.name}",
                    mode="wb+",
                    **tensorizer_args.stream_kwargs,
                ) as stream,
            ):
                logger.info("Writing artifact %s", artifact.name)
                stream.write(f.read())


def serialize_vllm_model(
    model: nn.Module,
    tensorizer_config: TensorizerConfig,
    model_config: "ModelConfig",
) -> nn.Module:
    model.register_parameter(
        "vllm_tensorized_marker",
        nn.Parameter(torch.tensor((1,), device="meta"), requires_grad=False),
    )

    tensorizer_args = tensorizer_config._construct_tensorizer_args()

    encryption_params = None
    if (keyfile := tensorizer_config.encryption_keyfile) is not None:
        with open(keyfile, "rb") as f:
            key = f.read()
        encryption_params = EncryptionParams(key=key)

    output_file = tensorizer_args.tensorizer_uri
    if tensorizer_config._is_sharded:
        from vllm.distributed import get_tensor_model_parallel_rank

        output_file = output_file % get_tensor_model_parallel_rank()

    with open_stream(
        output_file, mode="wb+", **tensorizer_args.stream_kwargs
    ) as stream:
        serializer = TensorSerializer(
            stream,
            encryption=encryption_params,
            **tensorizer_config.serialization_kwargs,
        )
        serializer.write_module(model)
        serializer.close()

    serialize_extra_artifacts(tensorizer_args, model_config.served_model_name)

    logger.info("Successfully serialized model to %s", str(output_file))
    return model


def tensorize_vllm_model(
    engine_args: "EngineArgs",
    tensorizer_config: TensorizerConfig,
    generate_keyfile: bool = True,
):
    """Utility to load a model and then serialize it with Tensorizer

    Intended to be used separately from running a vLLM server since it
    creates its own Engine instance.
    """
    engine_config = engine_args.create_engine_config()
    tensorizer_config.verify_with_model_config(engine_config.model_config)
    tensorizer_config.verify_with_parallel_config(engine_config.parallel_config)

    # generate the encryption key before creating the engine to support sharding
    if (
        generate_keyfile
        and (keyfile := tensorizer_config.encryption_keyfile) is not None
    ):
        encryption_params = EncryptionParams.random()
        with open_stream(
            keyfile,
            mode="wb+",
            s3_access_key_id=tensorizer_config.s3_access_key_id,
            s3_secret_access_key=tensorizer_config.s3_secret_access_key,
            s3_endpoint=tensorizer_config.s3_endpoint,
        ) as stream:
            stream.write(encryption_params.key)

    from vllm.v1.engine.llm_engine import LLMEngine

    engine = LLMEngine.from_vllm_config(engine_config)
    engine.collective_rpc(
        "save_tensorized_model",
        kwargs={"tensorizer_config": tensorizer_config.to_serializable()},
    )


def tensorize_lora_adapter(lora_path: str, tensorizer_config: TensorizerConfig):
    """
    Uses tensorizer to serialize a LoRA adapter. Assumes that the files
    needed to load a LoRA adapter are a safetensors-format file called
    adapter_model.safetensors and a json config file called adapter_config.json.

    Serializes the files in the tensorizer_config.tensorizer_dir
    """
    import safetensors

    from vllm.lora.utils import get_adapter_absolute_path

    lora_dir = get_adapter_absolute_path(lora_path)

    tensor_path = config_path = ""

    for file in os.listdir(lora_dir):
        if file.startswith("adapter_model"):
            tensor_path = lora_dir + "/" + file
        if file.startswith("adapter_config"):
            config_path = lora_dir + "/" + file
        if tensor_path and config_path:
            break

    if tensor_path.endswith(".safetensors"):
        tensors = safetensors.torch.load_file(tensor_path)
    elif tensor_path.endswith(".bin"):
        tensors = torch.load(tensor_path, weights_only=True)
    else:
        raise ValueError(
            f"Unsupported adapter model file: {tensor_path}. "
            f"Must be a .safetensors or .bin file."
        )

    with open(config_path) as f:
        config = json.load(f)

    tensorizer_args = tensorizer_config._construct_tensorizer_args()

    with open_stream(
        f"{tensorizer_config.tensorizer_dir}/adapter_config.json",
        mode="wb+",
        **tensorizer_args.stream_kwargs,
    ) as f:
        f.write(json.dumps(config).encode("utf-8"))

    lora_uri = f"{tensorizer_config.tensorizer_dir}/adapter_model.tensors"
    with open_stream(lora_uri, mode="wb+", **tensorizer_args.stream_kwargs) as f:
        serializer = TensorSerializer(f)
        serializer.write_state_dict(tensors)
        serializer.close()

    logger.info(
        "Successfully serialized LoRA files to %s",
        str(tensorizer_config.tensorizer_dir),
    )
