#######################
'''
License: MIT
'''
#######################


##### Dependencies

""" IMPORTANT: Uncomment the following line if you are in a Colab/Notebook environment """

#!pip install gradio einops accelerate bitsandbytes transformers

#####

import gradio as gr
import transformers
from transformers import AutoTokenizer, AutoModelForCausalLM
import torch
import random
import spaces
import re

def cut_text_after_last_token(text, token):

    last_occurrence = text.rfind(token)

    if last_occurrence != -1:
        result = text[last_occurrence + len(token):].strip()
        return result
    else:
        return None


class _SentinelTokenStoppingCriteria(transformers.StoppingCriteria):

    def __init__(self, sentinel_token_ids: torch.LongTensor,
                 starting_idx: int):
        transformers.StoppingCriteria.__init__(self)
        self.sentinel_token_ids = sentinel_token_ids
        self.starting_idx = starting_idx

    def __call__(self, input_ids: torch.LongTensor,
                 _scores: torch.FloatTensor) -> bool:
        for sample in input_ids:
            trimmed_sample = sample[self.starting_idx:]

            if trimmed_sample.shape[-1] < self.sentinel_token_ids.shape[-1]:
                continue

            for window in trimmed_sample.unfold(
                    0, self.sentinel_token_ids.shape[-1], 1):
                if torch.all(torch.eq(self.sentinel_token_ids, window)):
                    return True
        return False





model_path = 'freecs/ArtificialThinker-Phi2'

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")

tokenizer = AutoTokenizer.from_pretrained(model_path, trust_remote_code=True)

model = AutoModelForCausalLM.from_pretrained(model_path, trust_remote_code=True, load_in_4bit=False, torch_dtype=torch.float16).to(device) #remove .to() if load_in_4/8bit = True


@spaces.GPU(enable_queue=True)
def phine(message, history, temperature, top_p, top_k, repetition_penalty, sys_message):


    n = 0
    context = ""
    if history and len(history) > 0:

        for x in history:
          for h in x:
            if n%2 == 0:
              context+=f"""\n<|prompt|>{h}\n"""
            else:
              pattern = re.compile(r'<details>.*?</details>')
              result = re.sub(pattern, '', h)
              context+=f"""<|response|>{result}"""
            n+=1
    else:

        context = ""




    prompt = f"""\n<|system|>{sys_message}"""+context+"\n<|prompt|>"+message+"<|endoftext|>\n<|reasoning|>"
    tokenized = tokenizer(prompt, return_tensors="pt").to(device)


    stopping_criteria_list = transformers.StoppingCriteriaList([
        _SentinelTokenStoppingCriteria(
            sentinel_token_ids=tokenizer(
                "<|endoftext|>",
                add_special_tokens=False,
                return_tensors="pt",
            ).input_ids.to(device),
            starting_idx=tokenized.input_ids.shape[-1])
    ])


    token = model.generate(**tokenized,
                        stopping_criteria=stopping_criteria_list,
                        do_sample=True,
                        max_length=2048, temperature=temperature, top_p=top_p, top_k = top_k, repetition_penalty = repetition_penalty
                           )

    completion = tokenizer.decode(token[0], skip_special_tokens=True)

    token = "<|reasoning|>"
    reasoning = cut_text_after_last_token(completion, token)
    prompt = f"""\n<|system|>{sys_message}"""+context+"\n<|prompt|>"+message+"\n<|reasoning|>"+reasoning+"\n<|response|>"

    tokenized = tokenizer(prompt, return_tensors="pt").to(device)
    token = model.generate(**tokenized,
                        stopping_criteria=stopping_criteria_list,
                        do_sample=True,
                        max_length=2048, temperature=temperature, top_p=top_p, top_k = top_k, repetition_penalty = repetition_penalty
                           )
    completion = tokenizer.decode(token[0], skip_special_tokens=True)
    token = "<|response|>"
    response = cut_text_after_last_token(completion, token)


    res = f"""<details><summary>Reasoning (Click Me)</summary>{reasoning}</details>\n\n{response}"""

    return res


demo = gr.ChatInterface(phine,
                        title="ArtificialThinker Demo on GPU",
                        description="A demo of [ArtificialThinker](https://huggingface.co/freecs/ArtificialThinker-Phi2) on GPU. ArtificialThinker is a 2.7B parameter model based on Phi 2. The model is suitable for commercial use and is licensed under the MIT license. I am not responsible for any outputs you generate. You are solely responsible for ensuring that your usage of the model complies with applicable laws and regulations. I am not affiliated with the authors of the model.",
                          additional_inputs=[
                              gr.Slider(0.1, 2.0, label="temperature", value=0.3),
                              gr.Slider(0.1, 2.0, label="Top P", value=0.9),
                              gr.Slider(1, 500, label="Top K", value=50),
                              gr.Slider(0.1, 2.0, label="Repetition Penalty", value=1.1),
                              gr.Textbox(label="System Prompt",max_lines=1,interactive=True, value="You are an AI assistant named Phine developed by FreeCS.org. You are polite and smart.")
                          ]
                          )

if __name__ == "__main__":
    demo.queue().launch(share=True, debug=False) #If debug=True causes problems you can set it to False