import json
from typing import List, Optional, Union


from llamafactory.data import get_dataset, get_template_and_fix_tokenizer
from llamafactory.extras.constants import IGNORE_INDEX
from llamafactory.extras.misc import get_device_count
from llamafactory.extras.packages import is_vllm_available
from llamafactory.hparams import get_infer_args
from llamafactory.model import load_tokenizer
from pydantic import BaseModel
from vllm.sampling_params import GuidedDecodingParams


from vllm import LLM, SamplingParams
from vllm.lora.request import LoRARequest


# 这里不需要写太好，transforms库后续更新自带vllm


def vllm_infer(
    inputs: Union[str, List[str]],
    model_name_or_path: str,
    adapter_name_or_path: Optional[str] = None,
    dataset: str = "alpaca_en_demo",
    dataset_dir: str = "data",
    template: str = "default",
    cutoff_len: int = 2048,
    max_samples: Optional[int] = None,
    vllm_config: str = "{}",
    save_name: str = "generated_predictions.jsonl",
    temperature: float = 0.95,
    top_p: float = 0.7,
    top_k: int = 50,
    guided_decoding_class: Optional[type[BaseModel]] = None,
    bad_words: Optional[List[str]] = None,
    logprobs: Optional[int] = None,
    max_new_tokens: int = 1024,
    repetition_penalty: float = 1.0,
    skip_special_tokens: bool = True,
    seed: Optional[int] = None,
    pipeline_parallel_size: int = 1,
    image_max_pixels: int = 768 * 768,
    image_min_pixels: int = 32 * 32,
):
    r"""Perform batch generation using vLLM engine, which supports tensor parallelism."""
    if pipeline_parallel_size > get_device_count():
        raise ValueError("Pipeline parallel size should be smaller than the number of gpus.")

    model_args, data_args, _, generating_args = get_infer_args(
        dict(
            model_name_or_path=model_name_or_path,
            adapter_name_or_path=adapter_name_or_path,
            dataset=dataset,
            dataset_dir=dataset_dir,
            template=template,
            cutoff_len=cutoff_len,
            max_samples=max_samples,
            preprocessing_num_workers=16,
            vllm_config=vllm_config,
            temperature=temperature,
            top_p=top_p,
            top_k=top_k,
            max_new_tokens=max_new_tokens,
            repetition_penalty=repetition_penalty,
        )
    )

    tokenizer_module = load_tokenizer(model_args)
    tokenizer = tokenizer_module["tokenizer"]
    template_obj = get_template_and_fix_tokenizer(tokenizer, data_args)
    template_obj.mm_plugin.expand_mm_tokens = False  # for vllm generate

    if guided_decoding_class:
        json_schema = guided_decoding_class.model_json_schema()
        guided_decoding_params = GuidedDecodingParams(json=json_schema)
    else:
        guided_decoding_params = None

    sampling_params = SamplingParams(
        repetition_penalty=generating_args.repetition_penalty or 1.0,  # repetition_penalty must > 0
        temperature=generating_args.temperature,
        top_p=generating_args.top_p or 1.0,  # top_p must > 0
        top_k=generating_args.top_k or -1,  # top_k must > 0
        stop_token_ids=template_obj.get_stop_token_ids(tokenizer),
        max_tokens=generating_args.max_new_tokens,
        skip_special_tokens=skip_special_tokens,
        seed=seed,
        guided_decoding=guided_decoding_params,
        bad_words=bad_words,
    )
    if model_args.adapter_name_or_path is not None:
        lora_request = LoRARequest("default", 1, model_args.adapter_name_or_path[0])
    else:
        lora_request = None

    engine_args = {
        "model": model_args.model_name_or_path,
        "trust_remote_code": True,
        "dtype": model_args.infer_dtype,
        "max_model_len": cutoff_len + max_new_tokens,
        # "tensor_parallel_size":  1,
        # "pipeline_parallel_size": pipeline_parallel_size,
        # "data_parallel_size": get_device_count(), // vllm0.8.5版本支持DP
        "disable_log_stats": True,
        "enable_lora": model_args.adapter_name_or_path is not None,
        "enable_prefix_caching": True,  # 是否启用前缀缓存
        "gpu_memory_utilization": 0.95,
        # "quantization": "bitsandbytes", # 是否启用vllm的 bitsandbytes 的量化加载
        # "load_format": "bitsandbytes",
    }
    if template_obj.mm_plugin.__class__.__name__ != "BasePlugin":
        engine_args["limit_mm_per_prompt"] = {"image": 4, "video": 2, "audio": 2}

    if isinstance(model_args.vllm_config, dict):
        engine_args.update(model_args.vllm_config)

    results = LLM(**engine_args).generate(inputs, sampling_params, lora_request=lora_request)
    return results