app.py

import gradio as gr
import anthropic
import json

# ── constants ──────────────────────────────────────────────────────────────
EXPENSE_CATS = [
    "Housing", "Food & groceries", "Transport", "Utilities",
    "Entertainment", "Health", "Education", "Clothing", "Other"
]
CAT_LIMITS = {
    "Housing": 30, "Food & groceries": 15, "Transport": 15,
    "Utilities": 10, "Entertainment": 10, "Health": 10,
    "Education": 10, "Clothing": 5, "Other": 10
}

# ── helpers ────────────────────────────────────────────────────────────────
def fmt(n: float) -> str:
    return f"${round(n):,}"

def pct(part: float, whole: float, decimals: int = 1) -> str:
    if whole == 0:
        return "0%"
    return f"{round(part / whole * 100, decimals)}%"


# ── core calculation ───────────────────────────────────────────────────────
def calculate_budget(
    gross_income: float,
    fed_tax_pct: float,
    state_tax_pct: float,
    fica_pct: float,
    medicare_pct: float,
    k401_pct: float,
    housing: float,
    food: float,
    transport: float,
    utilities: float,
    entertainment: float,
    health: float,
    education: float,
    clothing: float,
    other: float,
    api_key: str,
):
    if gross_income <= 0:
        return (
            "⚠️ Please enter a valid gross income.",
            "", "", "", "", "", ""
        )

    # ── deductions ──
    fed_amt    = gross_income * fed_tax_pct   / 100
    state_amt  = gross_income * state_tax_pct / 100
    fica_amt   = gross_income * fica_pct      / 100
    medicare_amt = gross_income * medicare_pct / 100
    k401_amt   = gross_income * k401_pct      / 100

    total_tax  = fed_amt + state_amt + fica_amt + medicare_amt
    total_ded  = total_tax + k401_amt
    takehome   = gross_income - total_ded

    # ── income flow summary ──
    flow_md = f"""## Income flow

| | Amount | % of gross |
|---|---|---|
| **Gross income** | **{fmt(gross_income)}** | 100% |
| Federal tax | -{fmt(fed_amt)} | {pct(fed_amt, gross_income)} |
| State tax | -{fmt(state_amt)} | {pct(state_amt, gross_income)} |
| Social Security | -{fmt(fica_amt)} | {pct(fica_amt, gross_income)} |
| Medicare | -{fmt(medicare_amt)} | {pct(medicare_amt, gross_income)} |
| 401(k) | -{fmt(k401_amt)} | {pct(k401_amt, gross_income)} |
| **Take-home pay** | **{fmt(takehome)}** | {pct(takehome, gross_income)} |
"""

    # ── expense breakdown ──
    expenses = {
        "Housing":          housing,
        "Food & groceries": food,
        "Transport":        transport,
        "Utilities":        utilities,
        "Entertainment":    entertainment,
        "Health":           health,
        "Education":        education,
        "Clothing":         clothing,
        "Other":            other,
    }
    used = {k: v for k, v in expenses.items() if v > 0}
    total_exp = sum(used.values())
    remaining = takehome - total_exp

    exp_rows = []
    for cat, amt in used.items():
        limit = CAT_LIMITS.get(cat, 10)
        cat_pct = round(amt / takehome * 100, 1) if takehome > 0 else 0
        status = "✅" if cat_pct <= limit * 0.8 else ("⚠️" if cat_pct <= limit else "🔴")
        exp_rows.append(
            f"| {status} {cat} | {fmt(amt)} | {cat_pct}% | {limit}% |"
        )

    exp_md = f"""## Spending breakdown (vs take-home)

| Category | Amount | % of take-home | Limit |
|---|---|---|---|
{''.join(chr(10) + r for r in exp_rows)}

**Total expenses:** {fmt(total_exp)} &nbsp;|&nbsp; **Remaining:** {fmt(remaining)} ({pct(remaining, takehome)} of take-home)
"""

    # ── summary metrics ──
    rem_emoji = "✅" if remaining >= 0 else "🔴"
    summary_md = f"""## Summary

| | |
|---|---|
| Gross income | {fmt(gross_income)} |
| Total taxes | {fmt(total_tax)} ({pct(total_tax, gross_income)}) |
| 401(k) saved | {fmt(k401_amt)} ({pct(k401_amt, gross_income)}) |
| Take-home | {fmt(takehome)} |
| Total expenses | {fmt(total_exp)} |
| {rem_emoji} Remaining | {fmt(remaining)} |
"""

    # ── AI advice via streaming ──
    if not api_key.strip():
        ai_advice = "⚠️ Enter your Anthropic API key to get personalized AI advice."
    else:
        exp_lines = "\n".join(
            f"- {cat}: {fmt(amt)} ({round(amt/takehome*100,1) if takehome else 0}% of take-home, limit {CAT_LIMITS.get(cat,10)}%)"
            for cat, amt in used.items()
        )
        prompt = f"""You are a friendly, practical personal finance advisor. Analyze this monthly budget and give 5-6 specific, actionable suggestions. Be direct — use numbered points. Reference the actual dollar amounts.

BUDGET:
Gross income: {fmt(gross_income)}/month
Taxes: {fmt(total_tax)} ({pct(total_tax, gross_income)} of gross)
401(k): {fmt(k401_amt)} ({pct(k401_amt, gross_income)} of gross)
Take-home: {fmt(takehome)}/month

EXPENSES:
{exp_lines}

Total expenses: {fmt(total_exp)}
Remaining: {fmt(remaining)} ({pct(remaining, gross_income)} of gross)

Give honest advice referencing the real numbers. 1-2 sentences per point."""

        try:
            client = anthropic.Anthropic(api_key=api_key.strip())
            ai_advice = ""
            with client.messages.stream(
                model="claude-sonnet-4-5",
                max_tokens=1000,
                messages=[{"role": "user", "content": prompt}],
            ) as stream:
                for text in stream.text_stream:
                    ai_advice += text
                    yield flow_md, exp_md, summary_md, ai_advice, \
                          fmt(gross_income), fmt(takehome), fmt(remaining)
            return

        except anthropic.AuthenticationError:
            ai_advice = "❌ Invalid API key. Check your Anthropic API key and try again."
        except Exception as e:
            ai_advice = f"❌ Error calling AI: {str(e)}"

    yield flow_md, exp_md, summary_md, ai_advice, \
          fmt(gross_income), fmt(takehome), fmt(remaining)


# ── Gradio UI ──────────────────────────────────────────────────────────────
with gr.Blocks(
    title="AI Budget Advisor",
    theme=gr.themes.Soft(primary_hue="violet"),
    css="""
        .section-header { font-weight: 600; font-size: 1rem; margin-bottom: 4px; }
        .metric-box { text-align: center; padding: 8px; }
    """
) as demo:

    gr.Markdown("# 💰 AI Budget Advisor")
    gr.Markdown(
        "Enter your gross income, pre-tax deductions, and monthly expenses. "
        "Add your [Anthropic API key](https://console.anthropic.com/) to get AI-powered personalized advice."
    )

    with gr.Row():
        api_key_input = gr.Textbox(
            label="🔑 Anthropic API key",
            placeholder="sk-ant-...",
            type="password",
            scale=2,
        )

    gr.Markdown("---")

    # ── INCOME ──
    with gr.Row():
        with gr.Column():
            gr.Markdown("### 📥 Gross income (before taxes)")
            gross_income = gr.Number(label="Monthly gross income ($)", value=5000, minimum=0)

    # ── PRE-TAX DEDUCTIONS ──
    gr.Markdown("### 🏛️ Pre-tax deductions")
    with gr.Row():
        fed_tax   = gr.Slider(0, 50,  value=22,   step=0.5, label="Federal income tax (%)")
        state_tax = gr.Slider(0, 15,  value=5,    step=0.5, label="State income tax (%)")
    with gr.Row():
        fica      = gr.Slider(0, 10,  value=6.2,  step=0.1, label="Social Security / FICA (%)")
        medicare  = gr.Slider(0, 5,   value=1.45, step=0.05, label="Medicare (%)")
    with gr.Row():
        k401      = gr.Slider(0, 30,  value=6,    step=0.5, label="401(k) contribution (%)")

    gr.Markdown("---")

    # ── EXPENSES ──
    gr.Markdown("### 💸 Monthly expenses")
    with gr.Row():
        housing       = gr.Number(label="Housing ($)",           value=1200, minimum=0)
        food          = gr.Number(label="Food & groceries ($)",  value=400,  minimum=0)
        transport     = gr.Number(label="Transport ($)",         value=200,  minimum=0)
    with gr.Row():
        utilities     = gr.Number(label="Utilities ($)",         value=150,  minimum=0)
        entertainment = gr.Number(label="Entertainment ($)",     value=100,  minimum=0)
        health        = gr.Number(label="Health ($)",            value=0,    minimum=0)
    with gr.Row():
        education     = gr.Number(label="Education ($)",         value=0,    minimum=0)
        clothing      = gr.Number(label="Clothing ($)",          value=0,    minimum=0)
        other         = gr.Number(label="Other ($)",             value=0,    minimum=0)

    gr.Markdown("---")

    calc_btn = gr.Button("🧮 Calculate + get AI advice", variant="primary", size="lg")

    # ── OUTPUTS ──
    gr.Markdown("---")
    gr.Markdown("## Results")

    with gr.Row():
        out_gross    = gr.Textbox(label="Gross income",  interactive=False)
        out_takehome = gr.Textbox(label="Take-home pay", interactive=False)
        out_remain   = gr.Textbox(label="Remaining",     interactive=False)

    with gr.Row():
        with gr.Column():
            out_flow    = gr.Markdown(label="Income flow")
        with gr.Column():
            out_summary = gr.Markdown(label="Summary")

    out_expenses = gr.Markdown(label="Spending breakdown")

    gr.Markdown("### 🤖 AI budget advisor")
    out_ai = gr.Markdown(label="AI advice", value="_AI advice will appear here after you calculate._")

    # ── wire up ──
    calc_btn.click(
        fn=calculate_budget,
        inputs=[
            gross_income,
            fed_tax, state_tax, fica, medicare, k401,
            housing, food, transport, utilities,
            entertainment, health, education, clothing, other,
            api_key_input,
        ],
        outputs=[out_flow, out_expenses, out_summary, out_ai,
                 out_gross, out_takehome, out_remain],
    )

    gr.Markdown(
        "---\n"
        "_Powered by [Claude](https://anthropic.com). "
        "This is a financial planning tool, not professional financial advice._"
    )

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