BillTracker/client/pages/PayoffPage.jsx

493 lines
21 KiB
JavaScript

import React, { useCallback, useEffect, useMemo, useState } from 'react';
import { AlertCircle, ArrowRight, Calculator, RefreshCw, RotateCcw, TrendingDown } from 'lucide-react';
import { toast } from 'sonner';
import { api } from '@/api';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
Select, SelectContent, SelectItem, SelectTrigger, SelectValue,
} from '@/components/ui/select';
import { cn } from '@/lib/utils';
import PayoffChart from '@/components/snowball/PayoffChart';
// ─── Helpers ──────────────────────────────────────────────────────────────────
function fmt(v) {
return (Number(v) || 0).toLocaleString(undefined, {
style: 'currency', currency: 'USD', minimumFractionDigits: 2, maximumFractionDigits: 2,
});
}
function fmtShort(v) {
const n = Number(v) || 0;
return n.toLocaleString(undefined, { style: 'currency', currency: 'USD', maximumFractionDigits: 0 });
}
function buildPayoffSchedule(balance, annualRatePct, monthlyPayment, oneTimeExtra = 0) {
if (!balance || balance <= 0 || !monthlyPayment || monthlyPayment <= 0) return [];
const rate = (annualRatePct || 0) / 100 / 12;
if (rate > 0 && monthlyPayment <= balance * rate) return [];
let bal = balance;
const months = [];
for (let i = 0; i < 600; i++) {
const interest = Math.round(bal * rate * 100) / 100;
const pmt = Math.min(bal + interest, i === 0 ? monthlyPayment + oneTimeExtra : monthlyPayment);
const principal = Math.max(0, pmt - interest);
bal = Math.round(Math.max(0, bal - principal) * 100) / 100;
months.push({ month: i + 1, balance: bal, interest });
if (bal < 0.01) break;
}
return months;
}
function payoffLabel(track, now = new Date()) {
if (!track.length) return null;
const d = new Date(now.getFullYear(), now.getMonth() + track.length, 1);
return d.toLocaleDateString(undefined, { month: 'short', year: 'numeric' });
}
function numMonths(track) {
if (!track.length) return null;
const y = Math.floor(track.length / 12);
const m = track.length % 12;
if (y === 0) return `${m} mo`;
if (m === 0) return `${y} yr`;
return `${y} yr ${m} mo`;
}
// ─── Stat card ────────────────────────────────────────────────────────────────
function StatCard({ label, value, sub, color = 'amber' }) {
const colors = {
amber: 'bg-amber-500/8 border-amber-400/20 text-amber-500 dark:text-amber-400',
teal: 'bg-teal-500/8 border-teal-400/20 text-teal-500 dark:text-teal-400',
slate: 'bg-muted/40 border-border/60 text-foreground',
};
return (
<div className={cn('rounded-xl border p-4 text-center', colors[color])}>
<p className="text-[11px] font-medium uppercase tracking-widest text-muted-foreground mb-1">{label}</p>
<p className={cn('text-2xl font-bold font-mono tabular-nums', colors[color])}>{value}</p>
{sub && <p className="text-[11px] text-muted-foreground mt-0.5">{sub}</p>}
</div>
);
}
// ─── Input row ────────────────────────────────────────────────────────────────
function InputRow({ label, hint, children }) {
return (
<div className="space-y-1.5">
<div className="flex items-baseline justify-between">
<Label className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">
{label}
</Label>
{hint && <span className="text-[11px] text-muted-foreground">{hint}</span>}
</div>
{children}
</div>
);
}
// ─── Empty states ─────────────────────────────────────────────────────────────
function EmptyDebts() {
return (
<div className="flex flex-col items-center justify-center rounded-xl border border-dashed border-border/60 bg-muted/10 px-6 py-16 text-center">
<TrendingDown className="h-10 w-10 text-muted-foreground/40 mb-4" />
<p className="text-sm font-medium text-foreground">No debts with a balance found</p>
<p className="text-xs text-muted-foreground mt-1">
Add a current balance to your bills on the{' '}
<a href="/snowball" className="underline text-primary hover:opacity-80">Snowball page</a>.
</p>
</div>
);
}
function NoSelection() {
return (
<div className="flex flex-col items-center justify-center rounded-xl border border-dashed border-border/60 bg-muted/10 px-6 py-16 text-center">
<Calculator className="h-10 w-10 text-muted-foreground/40 mb-4" />
<p className="text-sm font-medium text-foreground">Select a loan or debt to begin</p>
<p className="text-xs text-muted-foreground mt-1">Choose from the dropdown above to run your simulation.</p>
</div>
);
}
// ─── PayoffPage ───────────────────────────────────────────────────────────────
export default function PayoffPage() {
const [bills, setBills] = useState([]);
const [extraPayment, setExtraPayment] = useState(0);
const [loading, setLoading] = useState(true);
const [loadError, setLoadError] = useState(null);
const [selectedId, setSelectedId] = useState(null);
// Per-simulation state (reset when bill changes)
const [simPayment, setSimPayment] = useState('');
const [simRate, setSimRate] = useState('');
const [oneTimeExtra, setOneTimeExtra] = useState('');
const [applying, setApplying] = useState(false);
const loadData = useCallback(() => {
setLoading(true);
setLoadError(null);
Promise.all([api.snowball(), api.snowballSettings()])
.then(([billData, settings]) => {
const debtBills = (billData || []).filter(b => (b.current_balance ?? 0) > 0);
setBills(debtBills);
setExtraPayment(Number(settings?.extra_payment) || 0);
if (debtBills.length > 0 && !selectedId) {
setSelectedId(debtBills[0].id);
}
})
.catch(err => setLoadError(err.message || 'Failed to load data'))
.finally(() => setLoading(false));
}, []); // eslint-disable-line react-hooks/exhaustive-deps
useEffect(() => { loadData(); }, [loadData]);
const bill = useMemo(() => bills.find(b => b.id === selectedId) ?? null, [bills, selectedId]);
const isAttack = bills[0]?.id === selectedId;
// Reset sim inputs whenever the selected bill changes
useEffect(() => {
if (!bill) return;
setSimPayment(String(Math.max(bill.minimum_payment ?? 0, bill.expected_amount ?? 0)));
setSimRate(String(bill.interest_rate ?? 0));
setOneTimeExtra('');
}, [bill?.id]); // eslint-disable-line react-hooks/exhaustive-deps
// Derived simulation tracks
const simPaymentN = Math.max(0, Number(simPayment) || 0);
const simRateN = Math.max(0, Number(simRate) || 0);
const oneTimeExtraN = Math.max(0, Number(oneTimeExtra) || 0);
const minPayment = bill?.minimum_payment ?? 0;
const { minTrack, currentTrack, simTrack } = useMemo(() => {
if (!bill) return { minTrack: [], currentTrack: [], simTrack: [] };
const b = bill.current_balance;
const min = minPayment > 0 ? minPayment : 0.01;
const currentPmt = isAttack ? min + extraPayment : min;
return {
minTrack: buildPayoffSchedule(b, simRateN, min),
currentTrack: buildPayoffSchedule(b, simRateN, currentPmt),
simTrack: buildPayoffSchedule(b, simRateN, simPaymentN, oneTimeExtraN),
};
}, [bill, simRateN, simPaymentN, oneTimeExtraN, minPayment, isAttack, extraPayment]);
const minInterest = useMemo(() => minTrack.reduce((s, m) => s + m.interest, 0), [minTrack]);
const simInterest = useMemo(() => simTrack.reduce((s, m) => s + m.interest, 0), [simTrack]);
const interestSavings = Math.max(0, minInterest - simInterest);
const timeSavings = Math.max(0, minTrack.length - simTrack.length);
const simTotalPaid = simInterest + (bill?.current_balance ?? 0);
const simPayoffLabel = payoffLabel(simTrack);
const minPayoffLabel = payoffLabel(minTrack);
const simDuration = numMonths(simTrack);
const paymentBelowMin = simPaymentN > 0 && simPaymentN < minPayment && minPayment > 0;
const paymentTooLow = bill && simPaymentN > 0 && simTrack.length === 0;
const defaultSimPayment = bill
? String(Math.max(bill.minimum_payment ?? 0, bill.expected_amount ?? 0))
: '';
const defaultRate = bill ? String(bill.interest_rate ?? 0) : '';
const isDirty = simPayment !== defaultSimPayment || simRate !== defaultRate || oneTimeExtra !== '';
const handleReset = () => {
if (!bill) return;
setSimPayment(defaultSimPayment);
setSimRate(defaultRate);
setOneTimeExtra('');
};
const handleApply = async () => {
if (!bill || applying) return;
setApplying(true);
try {
await api.updateBill(bill.id, { expected_amount: simPaymentN });
toast.success(`"${bill.name}" updated to ${fmt(simPaymentN)}/mo`, {
action: {
label: 'Undo',
onClick: async () => {
await api.updateBill(bill.id, { expected_amount: bill.expected_amount });
toast.success('Reverted');
loadData();
},
},
});
loadData();
} catch {
toast.error('Failed to update bill');
} finally {
setApplying(false);
}
};
// ── Render ──────────────────────────────────────────────────────────────────
if (loading) {
return (
<div className="space-y-6 animate-pulse">
<div className="h-8 w-64 rounded-lg bg-muted/50" />
<div className="h-4 w-96 rounded bg-muted/50" />
<div className="grid grid-cols-1 lg:grid-cols-[360px_1fr] gap-6">
<div className="space-y-4">
{[1, 2, 3, 4].map(i => (
<div key={i} className="h-16 rounded-xl bg-muted/40" />
))}
</div>
<div className="h-96 rounded-xl bg-muted/40" />
</div>
</div>
);
}
if (loadError) {
return (
<div className="flex flex-col items-center justify-center py-24 text-center rounded-xl border border-destructive/20 bg-destructive/5">
<AlertCircle className="h-10 w-10 text-destructive mb-3" />
<p className="text-sm font-medium">Failed to load data</p>
<p className="mt-1 text-xs text-muted-foreground">{loadError}</p>
<Button size="sm" variant="outline" onClick={loadData} className="mt-4 gap-1.5 text-xs">
<RefreshCw className="h-3 w-3" /> Try again
</Button>
</div>
);
}
return (
<div>
{/* Page header */}
<div className="mb-6 flex items-start justify-between gap-4">
<div>
<h1 className="text-2xl font-bold tracking-tight">Payoff Simulator</h1>
<p className="text-sm text-muted-foreground mt-0.5">
Explore how extra payments reduce interest and shorten your payoff timeline.
</p>
</div>
{isDirty && (
<Button size="sm" variant="ghost" onClick={handleReset} className="gap-1.5 text-xs shrink-0 mt-1">
<RotateCcw className="h-3 w-3" /> Reset
</Button>
)}
</div>
{/* Bill selector */}
<div className="mb-6">
{bills.length === 0 ? (
<EmptyDebts />
) : (
<Select value={selectedId ? String(selectedId) : ''} onValueChange={v => setSelectedId(Number(v))}>
<SelectTrigger className="w-72">
<SelectValue placeholder="Select a loan or debt…" />
</SelectTrigger>
<SelectContent>
{bills.map(b => (
<SelectItem key={b.id} value={String(b.id)}>
<span className="font-medium">{b.name}</span>
{b.current_balance ? (
<span className="ml-2 text-muted-foreground font-mono text-xs">
{fmt(b.current_balance)}
</span>
) : null}
</SelectItem>
))}
</SelectContent>
</Select>
)}
</div>
{/* Main content: left panel + right panel */}
{!bill ? (
bills.length > 0 ? <NoSelection /> : null
) : (
<div className="grid grid-cols-1 lg:grid-cols-[340px_1fr] gap-6 items-start">
{/* ── Left panel ── */}
<div className="table-surface p-5 space-y-5">
{/* Required minimum */}
<div className="rounded-lg bg-muted/30 px-4 py-3 flex items-center justify-between">
<span className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">
Required Minimum
</span>
<span className="font-mono text-lg font-bold tabular-nums">
{minPayment > 0 ? fmt(minPayment) : <span className="text-muted-foreground text-sm">Not set</span>}
</span>
</div>
{minPayment <= 0 && (
<p className="text-xs text-amber-600 dark:text-amber-400 flex items-center gap-1.5">
<AlertCircle className="h-3.5 w-3.5 shrink-0" />
Set a minimum payment on the Snowball page for best results.
</p>
)}
{/* Interest rate */}
<InputRow label="Interest Rate" hint="Override to test scenarios">
<div className="flex items-center gap-2">
<Input
type="number" min="0" max="99" step="0.01"
value={simRate}
onChange={e => setSimRate(e.target.value)}
className="font-mono"
placeholder="0.00"
/>
<span className="text-sm text-muted-foreground shrink-0">%</span>
</div>
</InputRow>
{/* Monthly payment */}
<InputRow label="Monthly Payment">
<Input
type="number" min="0" step="1"
value={simPayment}
onChange={e => setSimPayment(e.target.value)}
className="font-mono"
placeholder="0.00"
/>
{paymentBelowMin && (
<p className="text-[11px] text-amber-600 dark:text-amber-400 flex items-center gap-1 mt-1">
<AlertCircle className="h-3 w-3 shrink-0" />
Below minimum payment of {fmt(minPayment)}
</p>
)}
{paymentTooLow && !paymentBelowMin && (
<p className="text-[11px] text-destructive flex items-center gap-1 mt-1">
<AlertCircle className="h-3 w-3 shrink-0" />
Payment too low to overcome interest
</p>
)}
{simPaymentN > 0 && simPaymentN !== (bill?.expected_amount ?? 0) && !paymentTooLow && (
<button
type="button"
onClick={handleApply}
disabled={applying}
className="mt-1.5 text-[11px] text-primary hover:underline flex items-center gap-1 disabled:opacity-50"
>
<ArrowRight className="h-3 w-3" />
{applying ? 'Applying…' : `Apply ${fmt(simPaymentN)}/mo to my budget`}
</button>
)}
</InputRow>
{/* One-time extra */}
<InputRow label="One-time Extra This Month" hint="Optional lump sum">
<div className="flex items-center gap-1">
<Input
type="number" min="0" step="100"
value={oneTimeExtra}
onChange={e => setOneTimeExtra(e.target.value)}
className="font-mono"
placeholder="0.00"
/>
<div className="flex flex-col gap-0.5">
<button
type="button"
className="rounded px-1.5 py-0.5 text-xs text-muted-foreground hover:bg-muted transition-colors"
onClick={() => setOneTimeExtra(String(Math.max(0, oneTimeExtraN + 100)))}
></button>
<button
type="button"
className="rounded px-1.5 py-0.5 text-xs text-muted-foreground hover:bg-muted transition-colors"
onClick={() => setOneTimeExtra(String(Math.max(0, oneTimeExtraN - 100)))}
></button>
</div>
</div>
</InputRow>
{/* Divider */}
<div className="border-t border-border/50" />
{/* Payoff date summary */}
<div className="space-y-2">
{simPayoffLabel ? (
<div className="flex items-baseline justify-between">
<span className="text-xs text-muted-foreground uppercase tracking-wider font-semibold">Payoff</span>
<div className="text-right">
<span className="text-xl font-bold font-mono text-amber-500 dark:text-amber-400">
{simPayoffLabel}
</span>
{simDuration && (
<p className="text-[11px] text-muted-foreground">{simDuration}</p>
)}
</div>
</div>
) : (
<p className="text-xs text-muted-foreground text-center">Enter a payment to see payoff date</p>
)}
{minPayoffLabel && simPayoffLabel && minPayoffLabel !== simPayoffLabel && (
<div className="flex items-baseline justify-between">
<span className="text-[11px] text-muted-foreground">Minimum only</span>
<span className="text-[11px] text-muted-foreground font-mono line-through">{minPayoffLabel}</span>
</div>
)}
</div>
</div>
{/* ── Right panel ── */}
<div className="space-y-4">
{/* Chart */}
{simTrack.length > 0 ? (
<PayoffChart
minTrack={minTrack}
currentTrack={currentTrack}
simTrack={simTrack}
startBalance={bill.current_balance}
/>
) : (
<div className="flex items-center justify-center rounded-xl border border-dashed border-border/60 bg-muted/10 h-[300px] text-sm text-muted-foreground">
{simPaymentN <= 0 ? 'Enter a monthly payment to see the chart' : 'Payment too low to pay off this debt'}
</div>
)}
{/* Stats row */}
{simTrack.length > 0 && (
<>
<div className="grid grid-cols-2 gap-3">
<StatCard
label="Interest Savings"
value={fmtShort(interestSavings)}
sub="vs minimum only"
color={interestSavings > 0 ? 'teal' : 'slate'}
/>
<StatCard
label="Time Savings"
value={timeSavings > 0 ? `${timeSavings} mo` : '—'}
sub={timeSavings > 0 ? 'months sooner' : 'same timeline'}
color={timeSavings > 0 ? 'amber' : 'slate'}
/>
</div>
{/* Breakdown */}
<div className="table-surface divide-y divide-border/50">
<div className="px-5 py-3 flex items-center justify-between">
<span className="text-sm text-muted-foreground">Balance today</span>
<span className="font-mono text-sm font-semibold">{fmt(bill.current_balance)}</span>
</div>
<div className="px-5 py-3 flex items-center justify-between">
<span className="text-sm text-muted-foreground">Total interest</span>
<span className="font-mono text-sm font-semibold text-rose-500">{fmt(simInterest)}</span>
</div>
<div className="px-5 py-3 flex items-center justify-between">
<span className="text-sm font-medium">Total paid</span>
<span className="font-mono text-sm font-bold">{fmt(simTotalPaid)}</span>
</div>
</div>
</>
)}
</div>
</div>
)}
</div>
);
}