app.py

import streamlit as st
import torch
import torch.nn as nn
import re
import numpy as np
from transformers import AutoTokenizer, AutoModelForSequenceClassification
import requests
from bs4 import BeautifulSoup

# Set page configuration
st.set_page_config(page_title="Aplikasi Deteksi Alergen", page_icon="🍲", layout="wide")

# Target label
target_columns = ['susu', 'kacang', 'telur', 'makanan_laut', 'gandum']

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

# Text cleaning
def clean_text(text):
    text = text.replace('--', ' ')
    text = re.sub(r"http\S+", "", text)
    text = re.sub('\n', ' ', text)
    text = re.sub("[^a-zA-Z0-9\s]", " ", text)
    text = re.sub(" {2,}", " ", text)
    text = text.strip().lower()
    return text

# Multilabel BERT model
class MultilabelBertClassifier(nn.Module):
    def __init__(self, model_name, num_labels):
        super(MultilabelBertClassifier, self).__init__()
        self.bert = AutoModelForSequenceClassification.from_pretrained(model_name, num_labels=num_labels)
        self.bert.classifier = nn.Linear(self.bert.config.hidden_size, num_labels)
        
    def forward(self, input_ids, attention_mask):
        outputs = self.bert(input_ids=input_ids, attention_mask=attention_mask)
        return outputs.logits

# Load model
@st.cache_resource
def load_model():
    tokenizer = AutoTokenizer.from_pretrained('indobenchmark/indobert-base-p2')
    model = MultilabelBertClassifier('indobenchmark/indobert-base-p1', len(target_columns))
    try:
        state_dict = torch.load('model/alergen_model.pt', map_location=device)
        if 'model_state_dict' in state_dict:
            model_state_dict = state_dict['model_state_dict']
        else:
            model_state_dict = state_dict
        new_state_dict = {k[7:] if k.startswith('module.') else k: v for k, v in model_state_dict.items()}
        model.load_state_dict(new_state_dict, strict=False)
        st.success("Model berhasil dimuat!")
    except Exception as e:
        st.error(f"Error loading model: {str(e)}")
        st.info("Menggunakan model tanpa pre-trained weights.")
    model.to(device)
    model.eval()
    return tokenizer, model

def predict_alergens(ingredients_text, tokenizer, model, threshold=0.5, max_length=128):
    cleaned_text = clean_text(ingredients_text)
    encoding = tokenizer.encode_plus(
        cleaned_text,
        add_special_tokens=True,
        max_length=max_length,
        truncation=True,
        return_tensors='pt',
        padding='max_length'
    )
    input_ids = encoding['input_ids'].to(device)
    attention_mask = encoding['attention_mask'].to(device)
    
    with torch.no_grad():
        outputs = model(input_ids=input_ids, attention_mask=attention_mask)
        probs = torch.sigmoid(outputs).cpu().numpy()[0]  # hasil sigmoid (0-1)

    results = []
    for i, label in enumerate(target_columns):
        present = probs[i] > threshold
        percent = float(probs[i]) * 100
        results.append({
            'label': label,
            'present': present,
            'probability': percent
        })
    return results

# Scrape Cookpad
def scrape_ingredients_from_url(url):
    try:
        headers = {"User-Agent": "Mozilla/5.0"}
        response = requests.get(url, headers=headers)
        soup = BeautifulSoup(response.text, 'html.parser')
        ingredients_div = soup.find('div', id='ingredients')
        if not ingredients_div:
            return None
        items = ingredients_div.find_all(['li', 'span'])
        ingredients = [item.get_text(strip=True) for item in items if item.get_text(strip=True)]
        return '\n'.join(ingredients)
    except Exception as e:
        st.error(f"Gagal mengambil data dari URL: {e}")
        return None

# Main App
def main():
    st.title("Aplikasi Deteksi Alergen dalam Resep")
    st.markdown("""
    Aplikasi ini memprediksi alergen yang terkandung dalam resep makanan berdasarkan bahan-bahan.
    """)
    
    with st.spinner("Memuat model..."):
        tokenizer, model = load_model()

    col1, col2 = st.columns([3, 2])
    
    with col1:
        st.subheader("Masukkan URL Resep dari Cookpad")
        url = st.text_input("Contoh: https://cookpad.com/id/resep/24678703-gulai-telur-tahu-dan-kacang-panjang")

        threshold = st.slider(
            "Atur Threshold Deteksi Alergen",
            min_value=0.1,
            max_value=0.9,
            value=0.5,
            step=0.05,
            help="Semakin rendah threshold, semakin sensitif model terhadap kemungkinan adanya alergen."
        )

        if st.button("Deteksi Alergen", type="primary"):
            if url:
                with st.spinner("Mengambil bahan resep dari URL..."):
                    ingredients = scrape_ingredients_from_url(url)
                
                if ingredients:
                    st.text_area("Daftar Bahan", ingredients, height=200)
                    with st.spinner("Menganalisis bahan..."):
                        alergens = predict_alergens(ingredients, tokenizer, model, threshold=threshold)
                    
                    with col2:
                        st.subheader("Hasil Deteksi")
                        emoji_map = {
                            'susu': '🥛',
                            'kacang': '🥜',
                            'telur': '🥚',
                            'makanan_laut': '🦐',
                            'gandum': '🌾'
                        }

                        detected = []
                        for result in alergens:
                            label = result['label']
                            name = label.replace('_', ' ').title()
                            prob = result['probability']
                            present = result['present']
                            emoji = emoji_map.get(label, '')
                            
                            if present:
                                st.error(f"{emoji} {name}: Terdeteksi ⚠️ ({prob:.2f}%)")
                                detected.append(name)
                            else:
                                st.success(f"{emoji} {name}: Tidak Terdeteksi ✓ ({prob:.2f}%)")

                        if detected:
                            st.warning(f"Resep ini mengandung alergen: {', '.join(detected)}")
                        else:
                            st.success("Resep ini tidak mengandung alergen yang terdeteksi.")
                else:
                    st.warning("Gagal mengambil bahan dari halaman Cookpad. Pastikan URL valid.")
            else:
                st.warning("Silakan masukkan URL resep terlebih dahulu.")

    with st.expander("Tentang Aplikasi"):
        st.markdown("""
        Aplikasi ini menggunakan model IndoBERT untuk deteksi 5 jenis alergen dari bahan resep:
        - Susu 🥛
        - Kacang 🥜
        - Telur 🥚
        - Makanan Laut 🦐
        - Gandum 🌾
        """)

if __name__ == "__main__":
    main()