# copied from https://github.com/SmartFlowAI/Llama3-XTuner-CN/blob/main/web_demo.py
# isort: skip_file
import copy
import warnings
from dataclasses import asdict, dataclass
from typing import Callable, List, Optional

import streamlit as st
import torch
from torch import nn
from transformers.generation.utils import (LogitsProcessorList,
                                           StoppingCriteriaList)
from transformers.utils import logging

from transformers import AutoTokenizer, AutoModelForCausalLM, BitsAndBytesConfig  # isort: skip
from peft import PeftModel

logger = logging.get_logger(__name__)
st.set_page_config(page_title="Llama3-Chinese")

import argparse

@dataclass
class GenerationConfig:
    # this config is used for chat to provide more diversity
    max_length: int = 8192
    max_new_tokens: int = 600
    top_p: float = 0.8
    temperature: float = 0.8
    do_sample: bool = True
    repetition_penalty: float = 1.05

@torch.inference_mode()
def generate_interactive(
    model,
    tokenizer,
    prompt,
    generation_config: Optional[GenerationConfig] = None,
    logits_processor: Optional[LogitsProcessorList] = None,
    stopping_criteria: Optional[StoppingCriteriaList] = None,
    prefix_allowed_tokens_fn: Optional[Callable[[int, torch.Tensor],
                                                List[int]]] = None,
    additional_eos_token_id: Optional[int] = None,
    **kwargs,
):
    inputs = tokenizer([prompt], return_tensors='pt')
    input_length = len(inputs['input_ids'][0])
    for k, v in inputs.items():
        inputs[k] = v.cuda()
    input_ids = inputs['input_ids']
    _, input_ids_seq_length = input_ids.shape[0], input_ids.shape[-1]
    if generation_config is None:
        generation_config = model.generation_config
    generation_config = copy.deepcopy(generation_config)
    model_kwargs = generation_config.update(**kwargs)
    bos_token_id, eos_token_id = (  # noqa: F841  # pylint: disable=W0612
        generation_config.bos_token_id,
        generation_config.eos_token_id,
    )
    if isinstance(eos_token_id, int):
        eos_token_id = [eos_token_id]
    if additional_eos_token_id is not None:
        eos_token_id.append(additional_eos_token_id)
    has_default_max_length = kwargs.get(
        'max_length') is None and generation_config.max_length is not None
    if has_default_max_length and generation_config.max_new_tokens is None:
        warnings.warn(
            f"Using 'max_length''s default ({repr(generation_config.max_length)}) \
                to control the generation length. "
            'This behaviour is deprecated and will be removed from the \
                config in v5 of Transformers -- we'
            ' recommend using `max_new_tokens` to control the maximum \
                length of the generation.',
            UserWarning,
        )
    elif generation_config.max_new_tokens is not None:
        generation_config.max_length = generation_config.max_new_tokens + \
            input_ids_seq_length
        if not has_default_max_length:
            logger.warn(  # pylint: disable=W4902
                f"Both 'max_new_tokens' (={generation_config.max_new_tokens}) "
                f"and 'max_length'(={generation_config.max_length}) seem to "
                "have been set. 'max_new_tokens' will take precedence. "
                'Please refer to the documentation for more information. '
                '(https://huggingface.co/docs/transformers/main/'
                'en/main_classes/text_generation)',
                UserWarning,
            )

    if input_ids_seq_length >= generation_config.max_length:
        input_ids_string = 'input_ids'
        logger.warning(
            f"Input length of {input_ids_string} is {input_ids_seq_length}, "
            f"but 'max_length' is set to {generation_config.max_length}. "
            'This can lead to unexpected behavior. You should consider'
            " increasing 'max_new_tokens'.")

    # 2. Set generation parameters if not already defined
    logits_processor = logits_processor if logits_processor is not None \
        else LogitsProcessorList()
    stopping_criteria = stopping_criteria if stopping_criteria is not None \
        else StoppingCriteriaList()

    logits_processor = model._get_logits_processor(
        generation_config=generation_config,
        input_ids_seq_length=input_ids_seq_length,
        encoder_input_ids=input_ids,
        prefix_allowed_tokens_fn=prefix_allowed_tokens_fn,
        logits_processor=logits_processor,
    )

    stopping_criteria = model._get_stopping_criteria(
        generation_config=generation_config,
        stopping_criteria=stopping_criteria)
    logits_warper = model._get_logits_warper(generation_config)

    unfinished_sequences = input_ids.new(input_ids.shape[0]).fill_(1)
    scores = None
    while True:
        model_inputs = model.prepare_inputs_for_generation(
            input_ids, **model_kwargs)
        # forward pass to get next token
        outputs = model(
            **model_inputs,
            return_dict=True,
            output_attentions=False,
            output_hidden_states=False,
        )

        next_token_logits = outputs.logits[:, -1, :]

        # pre-process distribution
        next_token_scores = logits_processor(input_ids, next_token_logits)
        next_token_scores = logits_warper(input_ids, next_token_scores)

        # sample
        probs = nn.functional.softmax(next_token_scores, dim=-1)
        if generation_config.do_sample:
            next_tokens = torch.multinomial(probs, num_samples=1).squeeze(1)
        else:
            next_tokens = torch.argmax(probs, dim=-1)

        # update generated ids, model inputs, and length for next step
        input_ids = torch.cat([input_ids, next_tokens[:, None]], dim=-1)
        model_kwargs = model._update_model_kwargs_for_generation(
            outputs, model_kwargs, is_encoder_decoder=False)
        unfinished_sequences = unfinished_sequences.mul(
            (min(next_tokens != i for i in eos_token_id)).long())

        output_token_ids = input_ids[0].cpu().tolist()
        output_token_ids = output_token_ids[input_length:]
        for each_eos_token_id in eos_token_id:
            if output_token_ids[-1] == each_eos_token_id:
                output_token_ids = output_token_ids[:-1]
        response = tokenizer.decode(output_token_ids, skip_special_tokens=True)

        yield response
        # stop when each sentence is finished
        # or if we exceed the maximum length
        if unfinished_sequences.max() == 0 or stopping_criteria(
                input_ids, scores):
            break


def on_btn_click():
    del st.session_state.messages


@st.cache_resource
def load_model(model_name_or_path, adapter_name_or_path=None, load_in_4bit=False):
    if load_in_4bit:
        quantization_config = BitsAndBytesConfig(
            load_in_4bit=True,
            bnb_4bit_compute_dtype=torch.float16,
            bnb_4bit_use_double_quant=True,
            bnb_4bit_quant_type="nf4",
            llm_int8_threshold=6.0,
            llm_int8_has_fp16_weight=False,
        )
    else:
        quantization_config = None

    model = AutoModelForCausalLM.from_pretrained(
        model_name_or_path,
        load_in_4bit=load_in_4bit,
        trust_remote_code=True,
        low_cpu_mem_usage=True,
        torch_dtype=torch.float16,
        device_map='auto',
        quantization_config=quantization_config
    )
    if adapter_name_or_path is not None:
        model = PeftModel.from_pretrained(model, adapter_name_or_path)
    model.eval()
    tokenizer = AutoTokenizer.from_pretrained(model_name_or_path, trust_remote_code=True)
    
    return model, tokenizer


def prepare_generation_config():
    with st.sidebar:
        st.title('超参数面板')
        # 大输入框
        system_prompt_content = st.text_area('系统提示词',
                "你是一个调皮活泼的中文智者，名字叫shareAI-Llama3，喜欢用有趣的语言和适当的表情回答问题。注意在编码任务中仍使用英文",
            height=200,
            key='system_prompt_content'
        )
        max_new_tokens = st.slider('最大回复长度', 100, 8192, 1020, step=8)
        top_p = st.slider('Top P', 0.0, 1.0, 0.8, step=0.01)
        temperature = st.slider('温度系数', 0.0, 1.0, 0.6, step=0.01)
        repetition_penalty = st.slider("重复惩罚系数", 1.0, 2.0, 1.07, step=0.01)
        st.button('重置聊天', on_click=on_btn_click)

    generation_config = GenerationConfig(max_new_tokens=max_new_tokens,
                                         top_p=top_p,
                                         temperature=temperature,
                                         repetition_penalty=repetition_penalty,
                                        )

    return generation_config

system_prompt = '<|begin_of_text|><<SYS>>\n{content}\n<</SYS>>\n\n'
user_prompt = '<|start_header_id|>user<|end_header_id|>\n\n{user}<|eot_id|>'
robot_prompt = '<|start_header_id|>assistant<|end_header_id|>\n\n{robot}<|eot_id|>'
cur_query_prompt = '<|start_header_id|>user<|end_header_id|>\n\n{user}<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n'


def combine_history(prompt):
    messages = st.session_state.messages
    total_prompt = ''
    for message in messages:
        cur_content = message['content']
        if message['role'] == 'user':
            cur_prompt = user_prompt.format(user=cur_content)
        elif message['role'] == 'robot':
            cur_prompt = robot_prompt.format(robot=cur_content)
        else:
            raise RuntimeError
        total_prompt += cur_prompt

    system_prompt_content = st.session_state.system_prompt_content
    system = system_prompt.format(content=system_prompt_content)
    total_prompt = system + total_prompt + cur_query_prompt.format(user=prompt)
    
    return total_prompt


def main(model_name_or_path, adapter_name_or_path):
    # torch.cuda.empty_cache()
    print('load model...')
    model, tokenizer = load_model(model_name_or_path, adapter_name_or_path=adapter_name_or_path, load_in_4bit=False)
    print('load model end.')

    st.title('Llama3-Chinese')

    generation_config = prepare_generation_config()

    # Initialize chat history
    if 'messages' not in st.session_state:
        st.session_state.messages = []

    # Display chat messages from history on app rerun
    for message in st.session_state.messages:
        with st.chat_message(message['role']):
            st.markdown(message['content'])

    # Accept user input
    if prompt := st.chat_input('解释一下Vue的原理'):
        # Display user message in chat message container
        with st.chat_message('user'):
            st.markdown(prompt)
        real_prompt = combine_history(prompt)
        # Add user message to chat history
        st.session_state.messages.append({
            'role': 'user',
            'content': prompt,
        })

        with st.chat_message('robot'):
            message_placeholder = st.empty()
            for cur_response in generate_interactive(
                    model=model,
                    tokenizer=tokenizer,
                    prompt=real_prompt,
                    additional_eos_token_id=128009,
                    **asdict(generation_config),
            ):
                # Display robot response in chat message container
                message_placeholder.markdown(cur_response + '▌')
            message_placeholder.markdown(cur_response)
        # Add robot response to chat history
        st.session_state.messages.append({
            'role': 'robot',
            'content': cur_response,  # pylint: disable=undefined-loop-variable
        })
        torch.cuda.empty_cache()


if __name__ == '__main__':

    import sys
    model_name_or_path = sys.argv[1]
    if len(sys.argv) >= 3:
        adapter_name_or_path = sys.argv[2]
    else:
        adapter_name_or_path = None
    main(model_name_or_path, adapter_name_or_path)
