import torch
import gradio as gr
from peft import PeftModel
from transformers import AutoModelForCausalLM, AutoTokenizer
import transformers


adapters_name = "1littlecoder/mistral-7b-mj-finetuned"
model_name = "bn22/Mistral-7B-Instruct-v0.1-sharded"
device = "cuda"

bnb_config = transformers.BitsAndBytesConfig(
    load_in_4bit=True,
    bnb_4bit_use_double_quant=True,
    bnb_4bit_quant_type="nf4",
    bnb_4bit_compute_dtype=torch.bfloat16
)

model = AutoModelForCausalLM.from_pretrained(
    model_name,
    load_in_4bit=True,
    torch_dtype=torch.bfloat16,
    quantization_config=bnb_config,
    device_map='auto'
)
model = PeftModel.from_pretrained(model, adapters_name)

tokenizer = AutoTokenizer.from_pretrained(model_name)
tokenizer.bos_token_id = 1

stop_token_ids = [0]

print(f"Successfully loaded the model {model_name} into memory")

def remove_substring(original_string, substring_to_remove):
    # Replace the substring with an empty string
    result_string = original_string.replace(substring_to_remove, '')
    return result_string

def list_to_string(input_list, delimiter=" "):
    """
    Convert a list to a string, joining elements with the specified delimiter.

    :param input_list: The list to convert to a string.
    :param delimiter: The separator to use between elements (default is a space).
    :return: A string composed of list elements separated by the delimiter.
    """
    return delimiter.join(map(str, input_list))

def format_prompt(message, history):
  prompt = "<s>"
  for user_prompt, bot_response in history:
    prompt += f"[INST] {user_prompt} [/INST]"
    prompt += f" {bot_response}</s> "
  prompt += f"[INST] {message} [/INST]"
  return prompt

def generate(
    prompt, history, temperature=0.9, max_new_tokens=256, top_p=0.95, repetition_penalty=1.0,
):
    temperature = float(temperature)
    if temperature < 1e-2:
        temperature = 1e-2
    top_p = float(top_p)

    generate_kwargs = dict(
        temperature=temperature,
        max_new_tokens=max_new_tokens,
        top_p=top_p,
        repetition_penalty=repetition_penalty,
        do_sample=True,
        seed=42,
    )

    formatted_prompt = format_prompt(prompt, history)

    encoded = tokenizer(formatted_prompt, return_tensors="pt", add_special_tokens=False)
    model_input = encoded
    model.to(device)
    generated_ids = model.generate(**model_input, max_new_tokens=200, do_sample=True)


    list_output = tokenizer.batch_decode(generated_ids)
    string_output = list_to_string(list_output)
    possible_output = remove_substring(string_output,formatted_prompt)
   
    return possible_output


additional_inputs=[
    gr.Slider(
        label="Temperature",
        value=0.9,
        minimum=0.0,
        maximum=1.0,
        step=0.05,
        interactive=True,
        info="Higher values produce more diverse outputs",
    ),
    gr.Slider(
        label="Max new tokens",
        value=256,
        minimum=0,
        maximum=1048,
        step=64,
        interactive=True,
        info="The maximum numbers of new tokens",
    ),
    gr.Slider(
        label="Top-p (nucleus sampling)",
        value=0.90,
        minimum=0.0,
        maximum=1,
        step=0.05,
        interactive=True,
        info="Higher values sample more low-probability tokens",
    ),
    gr.Slider(
        label="Repetition penalty",
        value=1.2,
        minimum=1.0,
        maximum=2.0,
        step=0.05,
        interactive=True,
        info="Penalize repeated tokens",
    )
]

css = """
  #mkd {
    height: 500px;
    overflow: auto;
    border: 1px solid #ccc;
  }
"""

with gr.Blocks(css=css) as demo:
    gr.HTML("<h1><center>Mistral 7B Instruct<h1><center>")
    gr.HTML("<h3><center>In this demo, you can chat with <a href='https://huggingface.co/mistralai/Mistral-7B-Instruct-v0.1'>Mistral-7B-Instruct</a> model. 💬<h3><center>")
    gr.HTML("<h3><center>Learn more about the model <a href='https://huggingface.co/docs/transformers/main/model_doc/mistral'>here</a>. 📚<h3><center>")
    gr.ChatInterface(
        generate,
        additional_inputs=additional_inputs,
        examples=[["What is the secret to life?"], ["Write me a recipe for pancakes."]]
    )

demo.queue(concurrency_count=75, max_size=100).launch(debug=True)