app.py

import torch
from transformers import AutoTokenizer, AutoModelForSequenceClassification
import gradio as gr
import os

# Path to the saved model directory inside the Space
model_dir = "./campaign_bert_model/campaign_bert_model/campaign-bert-model"

# Load tokenizer and model
try:
    tokenizer = AutoTokenizer.from_pretrained(model_dir)
    model = AutoModelForSequenceClassification.from_pretrained(model_dir)
    model.eval()
except Exception as e:
    raise RuntimeError(f"❌ Failed to load model or tokenizer: {e}")

# Map the 5 classes to tones and templates
class_map = {
    0: ("Informative", "Here are plan details tailored for your interest."),
    1: ("Excited", "Great news! You’re eligible for our premium plans!"),
    2: ("Neutral", "Explore various insurance options with us."),
    3: ("Persuasive", "Take the first step to secure your future today."),
    4: ("Empathetic", "We understand your needs—here’s how we can help."),
}

def predict(text):
    try:
        if not text.strip():
            return "<h3 style='color:red'>⚠️ Please enter a message.</h3>", ""

        # Tokenize input
        inputs = tokenizer(text, return_tensors="pt", truncation=True, padding=True)

        # Run model inference
        with torch.no_grad():
            outputs = model(**inputs)

        logits = outputs.logits

        if logits is None or logits.shape[1] != len(class_map):
            return f"<h3 style='color:red'>❌ Invalid model output shape: {logits.shape}</h3>", ""

        probs = torch.softmax(logits, dim=1)
        pred_class = torch.argmax(probs, dim=1).item()
        confidence = probs[0][pred_class].item()

        tone, template = class_map[pred_class]

        return (
            f"<h3 style='color:green'>Tone: {tone}</h3><p>📨 Suggested Campaign Message:<br><b>{template}</b></p>",
            f"<p>Confidence: <b>{confidence:.2%}</b></p>"
        )

    except Exception as e:
        return f"<h3 style='color:red'>Error: {str(e)}</h3>", ""

# Gradio UI
iface = gr.Interface(
    fn=predict,
    inputs=gr.Textbox(label="Client Message", placeholder="E.g. I want to know about child education plans"),
    outputs=[
        gr.HTML(label="Prediction"),
        gr.HTML(label="Confidence"),
    ],
    title="📢 Campaign Personalizer",
    description="Predicts message tone and template using a fine-tuned BERT model with 5 classes.",
    allow_flagging="never"
)

iface.launch()