import os
import sys
import torch
import uvicorn, json, datetime

from fastapi import FastAPI, Request
from transformers import AutoTokenizer, AutoModel
from transformers import (
    HfArgumentParser,
    AutoConfig
)
from arguments import ModelArguments

DEVICE = "cuda"
DEVICE_ID = "0"
CUDA_DEVICE = f"{DEVICE}:{DEVICE_ID}" if DEVICE_ID else DEVICE


def torch_gc():
    if torch.cuda.is_available():
        with torch.cuda.device(CUDA_DEVICE):
            torch.cuda.empty_cache()
            torch.cuda.ipc_collect()


app = FastAPI()


@app.post("/")
async def create_item(request: Request):
    global model, tokenizer
    json_post_raw = await request.json()
    json_post = json.dumps(json_post_raw)
    json_post_list = json.loads(json_post)
    prompt = json_post_list.get('prompt')
    history = json_post_list.get('history')
    max_length = json_post_list.get('max_length')
    top_p = json_post_list.get('top_p')
    temperature = json_post_list.get('temperature')
    response, history = model.chat(tokenizer,
                                   prompt,
                                   history=history,
                                   max_length=max_length if max_length else 2048,
                                   top_p=top_p if top_p else 0.7,
                                   temperature=temperature if temperature else 0.95)
    now = datetime.datetime.now()
    time = now.strftime("%Y-%m-%d %H:%M:%S")
    answer = {
        "response": response,
        "history": history,
        "status": 200,
        "time": time
    }
    log = "[" + time + "] " + '", prompt:"' + prompt + '", response:"' + repr(response) + '"'
    print(log)
    torch_gc()
    return answer


if __name__ == '__main__':
    parser = HfArgumentParser(
        (ModelArguments))
    if len(sys.argv) == 2 and sys.argv[1].endswith(".json"):
        # If we pass only one argument to the script and it's the path to a json file,
        # let's parse it to get our arguments.
        model_args = parser.parse_json_file(json_file=os.path.abspath(sys.argv[1]))[0]
    else:
        model_args = parser.parse_args_into_dataclasses()[0]

    tokenizer = AutoTokenizer.from_pretrained(
        model_args.model_name_or_path, trust_remote_code=True)
    config = AutoConfig.from_pretrained(
        model_args.model_name_or_path, trust_remote_code=True)

    config.pre_seq_len = model_args.pre_seq_len
    config.prefix_projection = model_args.prefix_projection

    if model_args.ptuning_checkpoint is not None:
        print(f"Loading prefix_encoder weight from {model_args.ptuning_checkpoint}")
        model = AutoModel.from_pretrained(model_args.model_name_or_path, config=config, trust_remote_code=True)
        prefix_state_dict = torch.load(os.path.join(model_args.ptuning_checkpoint, "pytorch_model.bin"))
        new_prefix_state_dict = {}
        for k, v in prefix_state_dict.items():
            if k.startswith("transformer.prefix_encoder."):
                new_prefix_state_dict[k[len("transformer.prefix_encoder."):]] = v
        model.transformer.prefix_encoder.load_state_dict(new_prefix_state_dict)
    else:
        model = AutoModel.from_pretrained(model_args.model_name_or_path, config=config, trust_remote_code=True)

    if model_args.quantization_bit is not None:
        print(f"Quantized to {model_args.quantization_bit} bit")
        model = model.quantize(model_args.quantization_bit)

    if model_args.pre_seq_len is not None:
        # P-tuning v2
        model = model.half().cuda()
        model.transformer.prefix_encoder.float().cuda()

    model.eval()
    uvicorn.run(app, host='0.0.0.0', port=8000, workers=1)