app.py

import gradio as gr
import matplotlib.pyplot as plt

# Helper function to format INR values
def format_rupees(value):
    inr = f"₹ {value:,.2f}"
    if value >= 1e7:
        cr = f" (₹ {value / 1e7:.2f} Cr)"
        return inr + cr
    return inr

def cmda_redevelopment_final_model(
    uds, num_owners, total_fsi, guideline_value, market_rate, construction_cost
):
    owner_fsi = 2.0
    premium_fsi = total_fsi - owner_fsi

    # Area calculations
    owner_total_area = owner_fsi * uds
    builder_area = premium_fsi * uds
    total_built_up_area = total_fsi * uds

    # Premium FSI Charges
    premium_fsi_charge = 0.4 * guideline_value * uds * premium_fsi

    # Construction cost for entire built-up area
    total_construction_cost = total_built_up_area * construction_cost

    # Builder Revenue
    builder_sale_value = builder_area * market_rate

    # Builder Profit
    builder_profit = builder_sale_value - total_construction_cost - premium_fsi_charge

    # Owner share
    uds_per_owner = uds / num_owners
    owner_area_per_owner = owner_total_area / num_owners

    # Chart
    fig, ax = plt.subplots(figsize=(6, 4))
    labels = ['Owner Area (2.0x UDS)', f'Builder Area ({premium_fsi:.1f}x UDS)', 'Total Area']
    values = [owner_total_area, builder_area, total_built_up_area]
    ax.bar(labels, values, edgecolor='black')
    ax.set_ylabel("Area (sq.ft)")
    ax.set_title("Redevelopment Share Breakdown")
    plt.tight_layout()

    # Output with formatted rupees
    result = {
        "Total UDS": f"{uds:.2f} sq.ft",
        "Total Built-up Area (FSI × UDS)": f"{total_built_up_area:.2f} sq.ft",
        "Owner Entitlement Area (2.0 × UDS)": f"{owner_total_area:.2f} sq.ft",
        f"Builder Saleable Area ({premium_fsi:.1f} × UDS)": f"{builder_area:.2f} sq.ft",

        "--- Builder Financials ---": "",
        "Premium FSI Charges (0.4 × guideline × UDS × extra FSI)": format_rupees(premium_fsi_charge),
        "Total Construction Cost (entire built-up area)": format_rupees(total_construction_cost),
        "Builder Revenue (@ market rate)": format_rupees(builder_sale_value),
        "Estimated Builder Profit": format_rupees(builder_profit),

        "--- Owner Breakdown ---": "",
        "Number of Owners": num_owners,
        "UDS per Owner": f"{uds_per_owner:.2f} sq.ft",
        "New Flat per Owner (2.0 × UDS)": f"{owner_area_per_owner:.2f} sq.ft"
    }

    return result, fig

# Gradio Interface
inputs = [
    gr.Number(label="Total UDS (in sq.ft)", value=450),
    gr.Number(label="Number of Owners", value=4),
    gr.Number(label="Total FSI (e.g., 2.8)", value=2.8, minimum=2.0, maximum=3.5, step=0.1),
    gr.Number(label="Guideline Value (₹/sq.ft)", value=5000),
    gr.Number(label="Market Rate (₹/sq.ft for builder sale)", value=9500),
    gr.Number(label="Construction Cost (₹/sq.ft)", value=3500),
]

outputs = [
    gr.JSON(label="CMDA Redevelopment Report"),
    gr.Plot(label="Redevelopment Share Chart")
]

app = gr.Interface(
    fn=cmda_redevelopment_final_model,
    inputs=inputs,
    outputs=outputs,
    title="CMDA Redevelopment Calculator (Fixed Owner FSI Model)",
    description=(
        "Owners receive flats at 2.0× their UDS. Builder gets only the premium FSI share, sells at market rate, "
        "and bears full construction cost and premium FSI charges. Figures over ₹1 Cr are shown in crores."
    )
)

if __name__ == "__main__":
    app.launch()