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

import hashlib
from dataclasses import field
from typing import TYPE_CHECKING, Any, Optional, Union

from pydantic.dataclasses import dataclass

from vllm.config.utils import config
from vllm.logger import init_logger

if TYPE_CHECKING:
    from vllm.model_executor.model_loader import LoadFormats
    from vllm.model_executor.model_loader.tensorizer import TensorizerConfig
else:
    LoadFormats = Any
    TensorizerConfig = Any

logger = init_logger(__name__)


@config
@dataclass
class LoadConfig:
    """Configuration for loading the model weights."""

    load_format: Union[str, LoadFormats] = "auto"
    """The format of the model weights to load:\n
    - "auto" will try to load the weights in the safetensors format and fall
    back to the pytorch bin format if safetensors format is not available.\n
    - "pt" will load the weights in the pytorch bin format.\n
    - "safetensors" will load the weights in the safetensors format.\n
    - "npcache" will load the weights in pytorch format and store a numpy cache
    to speed up the loading.\n
    - "dummy" will initialize the weights with random values, which is mainly
    for profiling.\n
    - "tensorizer" will use CoreWeave's tensorizer library for fast weight
    loading. See the Tensorize vLLM Model script in the Examples section for
    more information.\n
    - "runai_streamer" will load the Safetensors weights using Run:ai Model
    Streamer.\n
    - "bitsandbytes" will load the weights using bitsandbytes quantization.\n
    - "sharded_state" will load weights from pre-sharded checkpoint files,
    supporting efficient loading of tensor-parallel models.\n
    - "gguf" will load weights from GGUF format files (details specified in
    https://github.com/ggml-org/ggml/blob/master/docs/gguf.md).\n
    - "mistral" will load weights from consolidated safetensors files used by
    Mistral models.
    - Other custom values can be supported via plugins."""
    download_dir: Optional[str] = None
    """Directory to download and load the weights, default to the default
    cache directory of Hugging Face."""
    model_loader_extra_config: Union[dict, TensorizerConfig] = field(
        default_factory=dict)
    """Extra config for model loader. This will be passed to the model loader
    corresponding to the chosen load_format."""
    device: Optional[str] = None
    """Device to which model weights will be loaded, default to
    device_config.device"""
    ignore_patterns: Optional[Union[list[str], str]] = None
    """The list of patterns to ignore when loading the model. Default to
    "original/**/*" to avoid repeated loading of llama's checkpoints."""
    use_tqdm_on_load: bool = True
    """Whether to enable tqdm for showing progress bar when loading model
    weights."""
    pt_load_map_location: Union[str, dict[str, str]] = "cpu"
    """
    pt_load_map_location: the map location for loading pytorch checkpoint, to
    support loading checkpoints can only be loaded on certain devices like
    "cuda", this is equivalent to {"": "cuda"}. Another supported format is
    mapping from different devices like from GPU 1 to GPU 0:
    {"cuda:1": "cuda:0"}. Note that when passed from command line, the strings
    in dictionary needs to be double quoted for json parsing. For more details,
    see original doc for `map_location` in https://pytorch.org/docs/stable/generated/torch.load.html
    """

    def compute_hash(self) -> str:
        """
        WARNING: Whenever a new field is added to this config,
        ensure that it is included in the factors list if
        it affects the computation graph.

        Provide a hash that uniquely identifies all the configs
        that affect the structure of the computation
        graph from input ids/embeddings to the final hidden states,
        excluding anything before input ids/embeddings and after
        the final hidden states.
        """
        # no factors to consider.
        # this config will not affect the computation graph.
        factors: list[Any] = []
        hash_str = hashlib.md5(str(factors).encode(),
                               usedforsecurity=False).hexdigest()
        return hash_str

    def __post_init__(self):
        self.load_format = self.load_format.lower()
        if self.ignore_patterns is not None and len(self.ignore_patterns) > 0:
            logger.info(
                "Ignoring the following patterns when downloading weights: %s",
                self.ignore_patterns)
        else:
            self.ignore_patterns = ["original/**/*"]