import streamlit as st
from PIL import Image, UnidentifiedImageError
import io
import uuid
import urllib.parse
import pytz
from datetime import datetime
from ocr_engine import extract_weight_from_image  # This must return (weight, confidence)

# Page setup
st.set_page_config(page_title="⚖️ Auto Weight Logger", layout="centered")
st.title("⚖️ Auto Weight Logger")

# Store keys/state
if "camera_key" not in st.session_state:
    st.session_state.camera_key = str(uuid.uuid4())
if "captured_time" not in st.session_state:
    st.session_state.captured_time = ""

# Select input type
input_mode = st.radio("📸 Select Input Method", ["Camera", "Upload"], horizontal=True)

# Clear/reset
if st.button("🔁 Clear / Retake"):
    st.session_state.camera_key = str(uuid.uuid4())
    st.session_state.captured_time = ""
    st.rerun()

# Init
image_bytes = None
image = None

# Capture time (IST)
def get_current_ist_time():
    ist = pytz.timezone("Asia/Kolkata")
    return datetime.now(ist).strftime("%Y-%m-%d %I:%M:%S %p")

# Handle camera
if input_mode == "Camera":
    cam_photo = st.camera_input("📷 Take a photo", key=st.session_state.camera_key)
    if cam_photo:
        image_bytes = cam_photo.getvalue()
        st.session_state.captured_time = get_current_ist_time()

# Handle upload
elif input_mode == "Upload":
    uploaded_file = st.file_uploader("📁 Upload an image (JPG/PNG)", type=["jpg", "jpeg", "png"])
    if uploaded_file:
        image_bytes = uploaded_file.read()
        st.session_state.captured_time = get_current_ist_time()

# Process if image exists
if image_bytes:
    try:
        image = Image.open(io.BytesIO(image_bytes))

        st.subheader("🖼️ Snapshot Image")
        st.image(image, use_column_width=True)

        if len(image_bytes) > 5 * 1024 * 1024:
            st.error("❌ Image is too large (>5MB).")
            st.stop()

        with st.spinner("🔍 Running OCR..."):
            weight, confidence = extract_weight_from_image(image)

        # Show captured time
        st.markdown(f"### 🕒 Captured At (IST): `{st.session_state.captured_time}`")

        # Show weight
        if not weight or confidence < 80:
            st.markdown(f"### 📦 Captured Weight: `Not Detected`")
            st.warning(f"⚠️ OCR Confidence too low ({int(confidence)}%)")
        else:
            st.markdown(f"### 📦 Captured Weight: `{weight} g`")
            st.success(f"✅ OCR Confidence: {int(confidence)}%")

        # Generate Salesforce URL
        device_id = "BAL-001"
        image_url = ""  # optional

        salesforce_url = (
            "https://autoweightlogger-dev-ed.my.salesforce-sites.com/"
            f"weight_logger_page?WeightInput={urllib.parse.quote(str(weight))}"
            f"&DeviceID={urllib.parse.quote(device_id)}&ImageURL={urllib.parse.quote(image_url)}"
        )

        st.markdown("### ✅ Send to Salesforce")
        st.markdown(f"[📤 Click to Log Weight in Salesforce]({salesforce_url})", unsafe_allow_html=True)

    except UnidentifiedImageError:
        st.error("❌ Invalid image file.")
    except Exception as e:
        st.error("❌ Unexpected error.")
        st.exception(e)