<?php

declare(strict_types=1);

namespace App\Filament\Widgets;

use App\Models\ContentView;
use App\Support\ContentTypes;
use Filament\Widgets\StatsOverviewWidget;
use Filament\Widgets\StatsOverviewWidget\Stat;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Cache;

/**
 * What the site is actually being read for, this month.
 *
 * The counters this panel started with said how many projects existed. This
 * says which three anybody opened, which is the number that changes what
 * somebody does next: it is the difference between a portfolio nobody visits
 * and one page carrying the whole site.
 *
 * Absent entirely until there is something to show. A widget reading "0, 0, 0"
 * on an installation whose frontend does not report views would be teaching
 * everybody to ignore that corner of the dashboard.
 */
class MostRead extends StatsOverviewWidget
{
    protected static ?int $sort = 2;

    protected const DAYS = 30;

    public static function canView(): bool
    {
        return (Auth::user()?->can('panel.access') ?? false)
            && ContentView::query()->since(self::DAYS)->exists();
    }

    /**
     * @return array<int, Stat>
     */
    protected function getStats(): array
    {
        return collect($this->top())
            ->map(fn (array $row) => Stat::make($row['title'], (string) $row['count'])
                ->description(__('panel.views.in_days', ['days' => self::DAYS]))
                ->descriptionIcon('heroicon-m-eye')
                ->color('info'))
            ->all();
    }

    /**
     * The three most-read records of any kind, resolved to their titles.
     *
     * Cached for a few minutes: this is drawn on the dashboard, which is the
     * first page everybody lands on, and the answer does not change minute to
     * minute — the underlying figures are daily totals.
     *
     * @return array<int, array{title: string, count: int}>
     */
    protected function top(): array
    {
        return Cache::remember('views:most-read', now()->addMinutes(5), function (): array {
            $rows = ContentView::query()
                ->since(self::DAYS)
                ->selectRaw('viewable_type, viewable_id, SUM(count) as total')
                ->groupBy('viewable_type', 'viewable_id')
                ->orderByDesc('total')
                ->limit(3)
                ->get();

            // Loaded per group rather than with the relation, because these
            // are three rows of different types and eager loading a morph for
            // three records buys nothing.
            return $rows
                ->map(function (ContentView $row): ?array {
                    $record = $row->viewable;

                    return $record instanceof Model
                        ? ['title' => ContentTypes::title($record), 'count' => (int) $row->total]
                        : null;
                })
                ->filter()
                ->values()
                ->all();
        });
    }
}