import pandas as pd
import gradio as gr
import plotly.express as px


def calculate_budget(income, currency, needs_pct, wants_pct, savings_pct):
    if needs_pct + wants_pct + savings_pct != 100:
        return gr.Markdown("❌ **Percentages must total 100%**"), None, None

    symbols = {
        "USD": "$",
        "INR": "₹",
        "EUR": "€",
        "GBP": "£",
        "AUD": "A$",
        "CAD": "C$",
    }
    sym = symbols.get(currency, "")

    data = {
        "Needs": income * needs_pct / 100,
        "Wants": income * wants_pct / 100,
        "Savings": income * savings_pct / 100,
    }

    df = pd.DataFrame(
        {
            "Category": data.keys(),
            "Amount": data.values(),
        }
    )

    fig = px.pie(
        df,
        names="Category",
        values="Amount",
        title="Budget Allocation",
        hole=0.4,
    )

    summary = f"""
### 💸 Monthly Budget Summary

- **Income:** {sym}{income:,.0f}  
- **Needs:** {sym}{data['Needs']:,.0f}  
- **Wants:** {sym}{data['Wants']:,.0f}  
- **Savings:** {sym}{data['Savings']:,.0f}  

✅ Allocation looks good!
"""

    csv = df.to_csv(index=False)

    return gr.Markdown(summary), fig, csv


with gr.Blocks(theme=gr.themes.Soft(), title="Monthly Budget Tracker") as demo:
    gr.Markdown(
        """
## 💸 Monthly Budget Tracker
Plan your money using the **50 / 30 / 20 rule** or customize it to your life.
"""
    )

    with gr.Row():
        income = gr.Number(label="Monthly Income", value=5000)
        currency = gr.Dropdown(
            ["USD", "INR", "EUR", "GBP", "AUD", "CAD"],
            value="INR",
            label="Currency",
        )

    gr.Markdown("### 🎯 Allocation (%)")

    with gr.Row():
        needs = gr.Slider(0, 100, value=50, label="Needs")
        wants = gr.Slider(0, 100, value=30, label="Wants")
        savings = gr.Slider(0, 100, value=20, label="Savings")

    calculate_btn = gr.Button("✨ Calculate Budget", variant="primary")

    with gr.Row():
        output_md = gr.Markdown()
    with gr.Row():
        output_chart = gr.Plot()
    with gr.Row():
        output_csv = gr.File(label="📥 Download CSV")

    calculate_btn.click(
        calculate_budget,
        inputs=[income, currency, needs, wants, savings],
        outputs=[output_md, output_chart, output_csv],
    )

demo.launch()