app.py

import gradio as gr
from transformers import AutoTokenizer
import onnxruntime as ort
import numpy as np
import string
from huggingface_hub import InferenceClient
import os

client = InferenceClient(api_key=os.environ.get('HF_TOKEN'))

# Model and ONNX setup
HG_MODEL = "livekit/turn-detector"
ONNX_FILENAME = "model_quantized.onnx"
PUNCS = string.punctuation.replace("'", "")
MAX_HISTORY = 4  # Adjusted to use the last 4 messages
MAX_HISTORY_TOKENS = 512
EOU_THRESHOLD = 0.5  # Updated threshold to match original

# Initialize ONNX model
tokenizer = AutoTokenizer.from_pretrained(HG_MODEL)
onnx_session = ort.InferenceSession(ONNX_FILENAME, providers=["CPUExecutionProvider"])

# Softmax function
def softmax(logits):
    exp_logits = np.exp(logits - np.max(logits))
    return exp_logits / np.sum(exp_logits)

# Normalize text
def normalize_text(text):
    def strip_puncs(text):
        return text.translate(str.maketrans("", "", PUNCS))
    return " ".join(strip_puncs(text).lower().split())

# Format chat context
def format_chat_ctx(chat_ctx):
    new_chat_ctx = []
    for msg in chat_ctx:
        if msg["role"] in ("user", "assistant"):
            content = normalize_text(msg["content"])
            if content:
                msg["content"] = content
                new_chat_ctx.append(msg)

    # Tokenize with chat template
    convo_text = tokenizer.apply_chat_template(
        new_chat_ctx, add_generation_prompt=False, add_special_tokens=False, tokenize=False
    )

    # Remove EOU token from the current utterance
    ix = convo_text.rfind("<|im_end|>")
    return convo_text[:ix]

# Calculate EOU probability
def calculate_eou(chat_ctx, session):
    formatted_text = format_chat_ctx(chat_ctx[-MAX_HISTORY:])  # Use the last 4 messages
    inputs = tokenizer(
        formatted_text,
        return_tensors="np",
        truncation=True,
        max_length=MAX_HISTORY_TOKENS,
    )
    input_ids = np.array(inputs["input_ids"], dtype=np.int64)
    outputs = session.run(["logits"], {"input_ids": input_ids})
    logits = outputs[0][0, -1, :]
    probs = softmax(logits)
    eou_token_id = tokenizer.encode("<|im_end|>")[-1]
    return probs[eou_token_id]


# Respond function
def respond(
    message,
    history: list[tuple[str, str]],
    max_tokens,
    temperature,
    top_p,
):
    # Keep the last 4 conversation pairs (user-assistant)
    messages = [{"role": "system", "content": os.environ.get("CHARACTER_DESC")}]

    for val in history[-20:]:
        if val[0]:
            messages.append({"role": "user", "content": val[0]})
        if val[1]:
            messages.append({"role": "assistant", "content": val[1]})

    # Add the new user message to the context
    messages.append({"role": "user", "content": message})

    # Calculate EOU probability
    # eou_prob = calculate_eou(messages, onnx_session)
    # print(f"EOU Probability: {eou_prob}")  # Debug output

    # # If EOU is below the threshold, ask for more input
    # if eou_prob < EOU_THRESHOLD:
    #     yield "[Waiting for user to continue input...]"
    #     return


    stream = client.chat.completions.create(
        model=os.environ.get('MODEL_ID'),
        messages=messages,
        temperature = 0.6,
        max_tokens= 2048,
        top_p = 0.9,
        stream=True
    )

    bot_response = ""
    for chunk in stream:
        bot_response += chunk.choices[0].delta.content
        yield bot_response
    


# Gradio interface
demo = gr.ChatInterface(
    respond,
    # additional_inputs=[
    #     # Commented out to disable user modification of the system message
    #     # gr.Textbox(value="You are an assistant.", label="System message"),
    #     gr.Slider(minimum=1, maximum=4096, value=256, step=1, label="Max new tokens"),
    #     gr.Slider(minimum=0.1, maximum=4.0, value=0.7, step=0.1, label="Temperature"),
    #     gr.Slider(
    #         minimum=0.1,
    #         maximum=1.0, value=0.95, step=0.05, label="Top-p (nucleus sampling)"
    #     ),
    # ],
)

if __name__ == "__main__":
    demo.launch()