<?php

declare(strict_types=1);

namespace App\Filament\Support;

use Filament\Tables\Columns\TextColumn;
use Illuminate\Database\Eloquent\Model;

/**
 * How often a record was read lately, in a listing.
 *
 * Reads the sum the query already carries — `withRecentViews()` on the
 * table's own query — rather than counting per row, because a column that
 * costs a query per row is a column that makes the whole list slow enough to
 * stop being opened.
 *
 * A published record with no views at all reads differently from one with
 * none because nothing has been reported yet, and the column cannot tell the
 * two apart on its own. So it says nothing rather than "0": until the frontend
 * starts reporting, an empty column is the honest answer.
 */
class ViewsColumn extends TextColumn
{
    protected function setUp(): void
    {
        parent::setUp();

        $this->badge();
        $this->placeholder('—');
        $this->alignEnd();

        $this->state(fn (Model $record): ?int => $record->recent_views > 0
            ? (int) $record->recent_views
            : null);

        $this->color(fn (?int $state) => match (true) {
            $state === null => 'gray',
            $state >= 100 => 'success',
            default => 'info',
        });

        $this->sortable(query: fn ($query, string $direction) => $query
            ->orderBy('recent_views', $direction));
    }
}