Filament monthly revenue chart with year filter

<?php

namespace App\Filament\Widgets;

use App\Models\Payment;
use Filament\Widgets\ChartWidget;
use Illuminate\Support\Facades\Cache;

class RevenueChart extends ChartWidget
{
    protected ?string $heading = 'Revenue by month';

    protected int|string|array $columnSpan = 'full';

    protected ?string $maxHeight = '300px';

    // Default filter value; the dropdown overrides $this->filter.
    public ?string $filter = null;

    protected function getFilters(): ?array
    {
        $years = range(now()->year, now()->year - 4);

        return array_combine($years, $years);
    }

    protected function getData(): array
    {
        $year = (int) ($this->filter ?: now()->year);

        // Cache briefly: the chart re-queries on every filter change and poll.
        $totals = Cache::remember("widget.revenue.$year", 300, fn () => Payment::query()
            ->whereYear('paid_at', $year)
            ->selectRaw('month(paid_at) as month, sum(amount) as total')
            ->groupBy('month')
            ->pluck('total', 'month'));

        // Always 12 points, so a quiet month shows as 0 instead of vanishing.
        $series = collect(range(1, 12))->map(fn (int $m) => round(($totals[$m] ?? 0) / 100, 2));

        return [
            'datasets' => [[
                'label' => "Revenue $year",
                'data' => $series->all(),
                'borderColor' => '#4f46e5',
                'backgroundColor' => 'rgba(79, 70, 229, 0.12)',
                'fill' => true,
                'tension' => 0.3,
            ]],
            'labels' => ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
        ];
    }

    protected function getType(): string
    {
        return 'line';
    }

    protected function getOptions(): array
    {
        return [
            'plugins' => ['legend' => ['display' => false]],
            'scales' => ['y' => ['beginAtZero' => true]],
        ];
    }
}