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

import json
import struct
from functools import cache
from os import PathLike
from pathlib import Path
from typing import Any, Optional, Union

from vllm.envs import VLLM_MODEL_REDIRECT_PATH
from vllm.logger import init_logger

logger = init_logger(__name__)


def is_s3(model_or_path: str) -> bool:
    return model_or_path.lower().startswith('s3://')


def check_gguf_file(model: Union[str, PathLike]) -> bool:
    """Check if the file is a GGUF model."""
    model = Path(model)
    if not model.is_file():
        return False
    elif model.suffix == ".gguf":
        return True

    try:
        with model.open("rb") as f:
            header = f.read(4)

        return header == b"GGUF"
    except Exception as e:
        logger.debug("Error reading file %s: %s", model, e)
        return False


def modelscope_list_repo_files(
    repo_id: str,
    revision: Optional[str] = None,
    token: Union[str, bool, None] = None,
) -> list[str]:
    """List files in a modelscope repo."""
    from modelscope.hub.api import HubApi
    api = HubApi()
    api.login(token)
    # same as huggingface_hub.list_repo_files
    files = [
        file['Path'] for file in api.get_model_files(
            model_id=repo_id, revision=revision, recursive=True)
        if file['Type'] == 'blob'
    ]
    return files


def _maybe_json_dict(path: Union[str, PathLike]) -> dict[str, str]:
    with open(path) as f:
        try:
            return json.loads(f.read())
        except Exception:
            return dict[str, str]()


def _maybe_space_split_dict(path: Union[str, PathLike]) -> dict[str, str]:
    parsed_dict = dict[str, str]()
    with open(path) as f:
        for line in f.readlines():
            try:
                model_name, redirect_name = line.strip().split()
                parsed_dict[model_name] = redirect_name
            except Exception:
                pass
    return parsed_dict


@cache
def maybe_model_redirect(model: str) -> str:
    """
    Use model_redirect to redirect the model name to a local folder.

    :param model: hf model name
    :return: maybe redirect to a local folder
    """

    model_redirect_path = VLLM_MODEL_REDIRECT_PATH

    if not model_redirect_path:
        return model

    if not Path(model_redirect_path).exists():
        return model

    redirect_dict = (_maybe_json_dict(model_redirect_path)
                     or _maybe_space_split_dict(model_redirect_path))
    if (redirect_model := redirect_dict.get(model)):
        logger.info("model redirect: [ %s ] -> [ %s ]", model, redirect_model)
        return redirect_model

    return model


def parse_safetensors_file_metadata(
        path: Union[str, PathLike]) -> dict[str, Any]:
    with open(path, "rb") as f:
        length_of_metadata = struct.unpack('<Q', f.read(8))[0]
        metadata = json.loads(f.read(length_of_metadata).decode('utf-8'))
        return metadata
