import streamlit as st
import fitz  # PyMuPDF
from PIL import Image
import pytesseract
import folium
from streamlit_folium import st_folium
import re
import tempfile
import requests

# Helper Functions
def extract_pdf_text(file):
    """Extract text from PDF."""
    with tempfile.NamedTemporaryFile(delete=False) as temp_file:
        temp_file.write(file.read())
        temp_path = temp_file.name
    doc = fitz.open(temp_path)
    text = ""
    for page in doc:
        text += page.get_text()
    return text

def extract_image_text(file):
    """Extract text from image."""
    img = Image.open(file)
    return pytesseract.image_to_string(img)

def extract_sanction_load_from_text(text):
    """Extract sanction load from the bill text."""
    match = re.search(r"load[:\-]?\s*(\d+)", text, re.IGNORECASE)
    return int(match.group(1)) if match else None

def extract_location_from_pdf(text):
    """Extract location from the second line of the PDF text."""
    lines = text.split('\n')
    if len(lines) >= 2:
        location = lines[1].strip()
        return location
    return None

def clean_address(address):
    """Clean the extracted address text to remove unnecessary characters."""
    if address:
        address = address.replace('\n', ' ').strip()
        address = re.sub(r'\s+', ' ', address)  # Replace multiple spaces with one
        return address
    return None

def extract_values_from_lines(text, start_line=53, end_line=60):
    """Extract numeric values from a specified range of lines in the text."""
    lines = text.split('\n')
    # Extract lines 53 to 60 (0-indexed, so 52 to 59 in the list)
    relevant_lines = lines[start_line-1:end_line]
    values = []
    for line in relevant_lines:
        match = re.search(r"(\d+\.?\d*)", line)  # Match numeric values (including decimals)
        if match:
            values.append(float(match.group(1)))  # Convert matched value to float
    return values

def get_suggested_solar_size(values):
    """Suggest the solar size based on the maximum value found."""
    if values:
        max_value = max(values)
        # Divide the maximum value by 360 to get the suggested solar size in kW
        suggested_size = max_value / 360
        return round(suggested_size, 2)  # Round to 2 decimal places for kW
    return None

def geocode_address_nominatim(address):
    """Convert address to latitude and longitude using Nominatim API."""
    if not address:
        return None, None
    
    url = f"https://nominatim.openstreetmap.org/search?format=json&q={address}"
    headers = {'User-Agent': 'EasySun-Solar-Planner/1.0 (your-email@example.com)'}
    try:
        response = requests.get(url, headers=headers)
        if response.status_code != 200:
            st.error(f"Failed to get a valid response from Nominatim API. Status Code: {response.status_code}")
            return None, None
        result = response.json()
        if result:
            lat = float(result[0]['lat'])
            lon = float(result[0]['lon'])
            st.write(f"Found location: Latitude {lat}, Longitude {lon}")
            return lat, lon
        else:
            st.error(f"No results found for address: {address}")
            return None, None
    except requests.exceptions.RequestException as e:
        st.error(f"Error connecting to Nominatim API: {e}")
        return None, None

def calculate_solar_system(area_sqft, panel_rating, inverter_type, backup_time=0):
    """Calculate solar system size and components for the Pakistan region."""
    panel_area_sqft = 20
    system_capacity_kw = (panel_rating / 1000) * (area_sqft / panel_area_sqft)  # Convert panel rating to kW
    num_panels = area_sqft // panel_area_sqft
    inverter_type = inverter_type.lower()
    
    # Default parameters
    battery_capacity = 0
    cable_length = system_capacity_kw * 1.5
    breaker_rating = system_capacity_kw * 1.25
    earthing = system_capacity_kw * 0.75

    # Inverter type based logic
    if inverter_type == "off-grid" or inverter_type == "hybrid":
        # Calculate battery capacity based on backup time (for Off-Grid and Hybrid only)
        if backup_time > 0:
            battery_capacity = system_capacity_kw * backup_time  # Assuming 1 hour of battery per kW system size
        else:
            st.warning("Please provide backup time for Off-Grid or Hybrid inverter type.")

    inverter_type = "Hybrid" if inverter_type == "hybrid" else "Off-Grid" if inverter_type == "off-grid" else "On-Grid"

    # Panels in series and strings in parallel calculations
    panels_in_series = 3
    strings_in_parallel = num_panels // panels_in_series
    
    return {
        "System Size (kW)": round(system_capacity_kw, 2),
        "Number of Panels": round(num_panels),
        "Inverter Type": inverter_type.capitalize(),
        "Battery Capacity (kWh)": round(battery_capacity, 2),
        "Cable Length (meters)": round(cable_length, 2),
        "Breaker Rating (Amps)": round(breaker_rating, 2),
        "Earthing (meters)": round(earthing, 2),
        "Panels in Series": panels_in_series,
        "Strings in Parallel": strings_in_parallel,
    }

# Streamlit UI
def main():
    st.set_page_config(page_title="🌞 EasySun: Solar Planner for All", layout="wide")

    # Header Section
    st.markdown(
        """
        <h1 style="text-align:center; color: #4CAF50;">🌞 EasySun: AI Solar Planner for All</h1>
        <p style="text-align:center; font-size: 18px;">Simplified Solar Planning for Pakistan</p>
        """, unsafe_allow_html=True)

    # File Upload Section
    st.markdown("### Step 1: Upload Your Electricity Bill")
    uploaded_file = st.file_uploader("Upload your electricity bill (PDF/JPG)", type=["pdf", "jpg", "jpeg"])
    sanction_load = None
    location = None
    city = None
    lat, lon = None, None

    if uploaded_file:
        with st.spinner("Extracting information from the uploaded file..."):
            if uploaded_file.type == "application/pdf":
                bill_text = extract_pdf_text(uploaded_file)
            else:
                bill_text = extract_image_text(uploaded_file)

            st.text_area("Extracted Text", bill_text)
            sanction_load = extract_sanction_load_from_text(bill_text)
            if sanction_load:
                st.success(f"Sanction Load Extracted: {sanction_load} kW")
            else:
                st.error("Unable to extract sanction load.")
            
            location = extract_location_from_pdf(bill_text)
            if location:
                location = clean_address(location)
                st.success(f"Location Extracted: {location}")
            else:
                st.error("Unable to extract location.")

    # City Input Section
    st.markdown("### Step 2: Enter the City Information")
    city = st.text_input("Enter the city of your location (required):")
    if not city:
        st.warning("City is required to proceed.")
        return

    # Full Address Generation
    full_address = f"{location}, {city}, Pakistan" if location else f"{city}, Pakistan"

    # Geocode Address Section
    st.markdown("### Step 3: Geolocation of Your Address")
    lat, lon = geocode_address_nominatim(full_address)
    if lat and lon:
        st.success(f"Location Found: Latitude {lat}, Longitude {lon}")
        map_ = folium.Map(location=[lat, lon], zoom_start=12)
        folium.Marker([lat, lon], popup=f"Location: {full_address}").add_to(map_)
        st_folium(map_, width=700, height=500)
    else:
        st.error(f"Unable to find the location: {full_address}.")

    # Extract Values and Suggested Solar Size Section
    st.markdown("### Step 4: Extract Solar Size from Bill")
    values = extract_values_from_lines(bill_text, start_line=53, end_line=60)
    if values:
        suggested_solar_size = get_suggested_solar_size(values)
        if suggested_solar_size:
            st.success(f"Suggested Solar System Size as per Utilization: {suggested_solar_size} kW")
        else:
            st.error("Unable to determine suggested solar size from the extracted values.")
    else:
        st.error("No numeric values found in lines 53-60.")

    # Solar System Calculation Section
    st.markdown("### Step 5: Solar System Calculation")
    panel_rating = st.number_input("Enter Panel Rating (in W):", min_value=1, step=1)
    inverter_type = st.selectbox("Select Inverter Type", ["On-Grid", "Off-Grid", "Hybrid"])
    backup_time = 0
    if inverter_type in ["Off-Grid", "Hybrid"]:
        backup_time = st.number_input("Enter Backup Time (hours):", min_value=1, step=1)

    area_sqft = st.number_input("Enter roof area (square feet):", min_value=1, step=1)
    if st.button("Calculate Solar System"):
        if area_sqft > 0 and panel_rating > 0:
            results = calculate_solar_system(area_sqft, panel_rating, inverter_type, backup_time)
            st.write("### Solar System Sizing Results")
            for key, value in results.items():
                st.write(f"- **{key}**: {value}")
            st.markdown("### Solar Panel Layout")
            for _ in range(results["Strings in Parallel"]):
                st.text("—".join(["🔋"] * results["Panels in Series"]))
        else:
            st.error("Please provide valid inputs for panel rating, roof area, and inverter type.")

    # ROI Calculation Section
    st.markdown("### Step 6: ROI Calculation")
    total_installation_cost = st.number_input("Enter total installation cost (in PKR):", min_value=1, step=1000)
    electricity_charges = st.number_input("Enter electricity charges (in PKR per kWh):", min_value=1, step=1)

    # Assuming monthly solar generation (this value can be adjusted based on location or other factors)
    solar_generation_per_month_kWh = st.number_input("Enter solar generation per month (in kWh):", min_value=1, step=10)

    if st.button("Calculate ROI"):
        if total_installation_cost > 0 and electricity_charges > 0 and solar_generation_per_month_kWh > 0:
            # Calculate monthly savings (based on solar generation and electricity charges)
            monthly_savings = solar_generation_per_month_kWh * electricity_charges
            
            # Calculate the ROI in months and years
            roi_months = total_installation_cost / monthly_savings
            roi_years = roi_months / 12
            
            st.write("### ROI Calculation Results")
            st.write(f"- **Monthly Savings**: {monthly_savings} PKR")
            st.write(f"- **ROI (Months)**: {roi_months:.2f} months")
            st.write(f"- **ROI (Years)**: {roi_years:.2f} years")
        else:
            st.error("Please provide valid inputs for installation cost, electricity charges, and solar generation.")

if __name__ == "__main__":
    main()