<?php

declare(strict_types=1);

namespace App\Filament\Support;

use App\Support\TranslationFreshness;
use Filament\Tables\Columns\TextColumn;
use Illuminate\Database\Eloquent\Model;

/**
 * Shows at a glance which languages a record has been translated into.
 *
 * Each supported locale renders as a badge — solid when a translation exists,
 * muted when it is still missing — so an editor can spot untranslated content
 * without opening every record.
 *
 * A third state matters as much as the first two and is invisible everywhere
 * else: a translation that exists and has fallen behind the language it was
 * made from. Nothing else in the panel would ever mention it, because by every
 * other measure that record is finished.
 */
class TranslationStatusColumn extends TextColumn
{
    /**
     * The translatable attribute whose presence stands in for "translated".
     * Defaults to the model's first translatable attribute.
     */
    protected ?string $trackedAttribute = null;

    protected function setUp(): void
    {
        parent::setUp();

        $this->badge();
        $this->sortable(false);
        $this->searchable(false);

        $this->state(function (Model $record): array {
            $attribute = $this->resolveTrackedAttribute($record);
            $translations = $record->getTranslations($attribute);
            $stale = TranslationFreshness::for($record);

            $states = [];

            foreach (array_keys(config('locales.supported')) as $locale) {
                if (blank($translations[$locale] ?? null)) {
                    $states[] = strtolower($locale);

                    continue;
                }

                // Translated, but the language it was translated from has
                // moved on since. The badge has to say something other than
                // "done", because as far as everything else is concerned this
                // record is finished.
                $states[] = isset($stale[$locale])
                    ? strtoupper($locale).'!'
                    : strtoupper($locale);
            }

            return $states;
        });

        /*
         * Uppercase = translated, lowercase = missing, and a "!" for a
         * translation the source has since moved past. Colour carries the same
         * three states for anyone who does not notice the casing.
         */
        $this->color(fn (string $state): string => match (true) {
            str_ends_with($state, '!') => 'warning',
            $state === strtoupper($state) => 'success',
            default => 'gray',
        });
    }

    public function trackedAttribute(string $attribute): static
    {
        $this->trackedAttribute = $attribute;

        return $this;
    }

    protected function resolveTrackedAttribute(Model $record): string
    {
        return $this->trackedAttribute
            ?? $record->getTranslatableAttributes()[0]
            ?? 'title';
    }
}