app.py

import pandas as pd
import gradio as gr
from sklearn.model_selection import train_test_split
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import classification_report

# 1 Load and clean the dataset
data = pd.read_csv("spam.csv")
data.drop_duplicates(inplace=True)
data['Category'] = data['Category'].replace(['ham', 'spam'], ['Not spam', 'Spam'])

# 2 Prepare the data
X = data['Message']
y = data['Category']

# 3 Train‑test split
X_train, X_test, y_train, y_test = train_test_split(
    X, y, test_size=0.2, random_state=42, stratify=y
)

# 4 Vectorizer (TF‑IDF instead of Bag‑of‑Words)
vectorizer = TfidfVectorizer(stop_words='english', ngram_range=(1, 2))

# 5 Transform text to features
X_train_tf = vectorizer.fit_transform(X_train)
X_test_tf  = vectorizer.transform(X_test)

# 6 Model (Logistic Regression)
model = LogisticRegression(max_iter=200, n_jobs=-1)
model.fit(X_train_tf, y_train)

# ⭐ Optional: print metrics to the HF Logs tab
print(classification_report(y_test, model.predict(X_test_tf)))

# 7 Prediction function
def predict_spam(message: str) -> str:
    features = vectorizer.transform([message])
    return model.predict(features)[0]

# 8 Build improved UI
with gr.Blocks(theme=gr.themes.Default()) as demo:
    gr.Markdown("## 📩 Spam Detector  |  TF‑IDF + Logistic Regression")
    
    with gr.Row():
        msg_box = gr.Textbox(
            label="Your Message",
            placeholder="e.g. Congratulations! You've won a prize...",
            lines=4,
        )
        output = gr.Label(label="Prediction")
    
    detect_btn = gr.Button("Detect Spam", variant="primary")
    detect_btn.click(fn=predict_spam, inputs=msg_box, outputs=output)
    
    gr.Examples(
        examples=[
            ["Congratulations! You've won a $1000 Walmart gift card."],
            ["Your PayPal account is on hold. Log in now to fix the issue."],
            ["Hey, let's meet for lunch tomorrow at 1?"],
            ["URGENT! Verify your bank details immediately or your account will be locked."],
        ],
        inputs=msg_box,
    )

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