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

# Define the BLOOM model name
model_name = "CreitinGameplays/bloom-3b-conversational"

# Load tokenizer and model
tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(model_name)

def generate_text(user_prompt):
  """Generates text using the BLOOM model from Hugging Face Transformers and removes the user prompt."""
  # Construct the full prompt with system introduction, user prompt, and assistant role
  prompt = f"<|system|> You are a helpful AI assistant. </s> <|prompter|> {user_prompt} </s> <|assistant|>"
  encoded_prompt = tokenizer(prompt, return_tensors="pt").input_ids

  # Initialize variables for real-time generation
  generated_text = ""
  current_output = torch.tensor([tokenizer.encode("<|assistant|>", return_tensors="pt").input_ids[0]])

  for char in user_prompt:
    # Encode character and concatenate with previous output
    encoded_char = torch.tensor([tokenizer.encode(char, return_tensors="pt").input_ids[0]])
    input_ids = torch.cat((current_output, encoded_char), dim=-1)

    # Generate text with the current prompt and encoded character
    output = model.generate(
        input_ids=input_ids,
        max_length=256,
        num_beams=1,
        num_return_sequences=1,  
        do_sample=True,  
        top_k=50,  
        top_p=0.95,  
        temperature=0.2,  
        repetition_penalty=1.155
    )

    # Decode the generated token sequence back to text
    decoded_text = tokenizer.decode(output[0], skip_special_tokens=True)

    # Extract and update generated text, removing special tokens
    generated_text += decoded_text.split("<|assistant|>")[-1].strip()
    current_output = input_ids

  # Remove prompt and user input from final response
  assistant_response = generated_text.replace(f"{user_prompt}", "").strip()
  assistant_response = assistant_response.replace("You are a helpful AI assistant.", "").strip()
  
  return assistant_response

# Define the Gradio interface with streaming enabled
interface = gr.Interface(
  fn=generate_text,
  inputs=[
      gr.Textbox(label="Text Prompt", value="", type="verbatim"),  # Set type to "verbatim" for character-by-character input
  ],
  outputs="text",
  description="Interact with BLOOM-3b-conversational (Loaded with Hugging Face Transformers)",
  **{"allow_user_code": True},  # Enable user code execution for real-time updates
)

# Launch the Gradio interface
interface.launch()