import streamlit as st
import pandas as pd
import matplotlib.pyplot as plt
from utils.preprocessing import clean_data
from utils.models import predict_umkm

# Konfigurasi tampilan
st.set_page_config(page_title="AI Supply Chain UMKM", layout="wide")
st.title("🛒 AI Manajemen Inventori UMKM")

# Sidebar untuk parameter
with st.sidebar:
    st.header("⚙️ Pengaturan")
    hari_prediksi = st.slider("Jumlah Hari Prediksi", 1, 14, 7)
    stok_aman = st.number_input("Stok Pengaman (Safety Stock)", min_value=0, value=10)

# Upload data
uploaded_file = st.file_uploader(
    "Upload Data Historis (Format CSV)",
    type="csv",
    help="Contoh format: tanggal, demand, supply"
)

if uploaded_file:
    try:
        # ===== 1. Preprocessing =====
        df = clean_data(uploaded_file)
        
        # Validasi kolom
        if not all(col in df.columns for col in ['tanggal', 'demand', 'supply']):
            raise ValueError("Format kolom harus: tanggal, demand, supply")
        
        # ===== 2. Visualisasi Data =====
        st.subheader("📈 Tren Historis")
        fig, ax = plt.subplots(figsize=(12, 6))
        
        ax.plot(df['tanggal'], df['demand'], label='Permintaan', color='#1f77b4', marker='o')
        ax.plot(df['tanggal'], df['supply'], label='Persediaan', color='#ff7f0e', marker='s')
        
        ax.fill_between(
            df['tanggal'], 
            df['demand'], 
            df['supply'], 
            where=(df['supply'] > df['demand']),
            color='#2ca02c', alpha=0.3, label='Surplus'
        )
        ax.fill_between(
            df['tanggal'], 
            df['demand'], 
            df['supply'], 
            where=(df['supply'] < df['demand']),
            color='#d62728', alpha=0.3, label='Defisit'
        )
        
        ax.set_xlabel("Tanggal")
        ax.set_ylabel("Jumlah Unit")
        ax.legend()
        ax.grid(True)
        st.pyplot(fig)

        # ===== 3. Prediksi & Rekomendasi =====
        st.subheader("🤖 Rekomendasi AI")
        
        with st.spinner("Menganalisis data..."):
            hasil = predict_umkm(
                data=df,
                prediction_length=hari_prediksi,
                safety_stock=stok_aman
            )
            
            st.success(f"**Rekomendasi:** {hasil['rekomendasi']}")
            
            with st.expander("📊 Detail Analisis"):
                st.write(f"**Prediksi {hari_prediksi} Hari:**")
                st.line_chart(pd.Series(hasil['prediksi'], name='Prediksi'))
                st.json({
                    "ROI Estimasi": f"{hasil['roi']}%",
                    "Stok Optimal": hasil['stok_optimal'],
                    "Anomali Terdeteksi": hasil['anomali']
                })

    except Exception as e:
        st.error(f"⚠️ Error: {str(e)}")
        st.info("Pastikan file CSV sesuai format contoh di bawah")
        
else:
    st.info("""
    **Contoh Data CSV:**
    ```csv
    tanggal,demand,supply
    2024-01-01,100,120
    2024-01-02,150,130
    2024-01-03,200,180
    ```
    """)