# app.py
import streamlit as st
from PIL import Image, ImageOps
import io

st.set_page_config(page_title="Image Filter App", layout="wide")

st.title("🖼️ Image Filter App")

# 3-column layout
col1, col2, col3 = st.columns([1, 1, 1])  # equal width

with col1:
    st.header("📤 Upload Image")
    st.caption("Max 5MB • Only PNG, JPG")
    uploaded_file = st.file_uploader("Choose an image", type=["png", "jpg", "jpeg"])

image = None
filtered_image = None
filter_option = "None"

if uploaded_file:
    # Size check
    uploaded_file.seek(0, io.SEEK_END)
    file_size = uploaded_file.tell()
    uploaded_file.seek(0)

    if file_size > 5 * 1024 * 1024:
        with col1:
            st.error("❌ File too large! Must be under 5MB.")
    else:
        image = Image.open(uploaded_file)

        with col2:
            st.header("🎛️ Select Filter")
            filter_option = st.radio("Choose filter:", ["None", "Grayscale", "Invert Colors"])

        with col3:
            st.header("🔍 Preview Output")

            if filter_option == "Grayscale":
                filtered_image = ImageOps.grayscale(image)
                st.image(filtered_image, caption="Grayscale", use_container_width=True)

            elif filter_option == "Invert Colors":
                if image.mode != "RGB":
                    image = image.convert("RGB")
                filtered_image = ImageOps.invert(image)
                st.image(filtered_image, caption="Inverted", use_container_width=True)

            else:
                st.info("Select a filter to see output.")