<?php

declare(strict_types=1);

namespace App\Services\Uploads;

use Illuminate\Support\Facades\File;
use Intervention\Image\ImageManager as ImageManager;
use Intervention\Image\Interfaces\ImageInterface as InterventionImageInterface;
use RuntimeException;

final class UploadDerivativesService
{
    private bool $imageAvailable = false;
    private ?ImageManager $manager = null;

    public function __construct(private readonly UploadStorageService $storage)
    {
        // Intervention Image v3 uses ImageManager; instantiate appropriate driver
        try {
            $this->manager = extension_loaded('gd') ? ImageManager::gd() : ImageManager::imagick();
            $this->imageAvailable = true;
        } catch (\Throwable $e) {
            logger()->warning('Intervention Image present but configuration failed: ' . $e->getMessage());
            $this->imageAvailable = false;
            $this->manager = null;
        }
    }

    public function storeOriginal(string $sourcePath, string $hash): string
    {
        $this->assertImageAvailable();

        $dir = $this->storage->ensureHashDirectory('originals', $hash);
        $target = $dir . DIRECTORY_SEPARATOR . 'orig.webp';
        $quality = (int) config('uploads.quality', 85);

        /** @var InterventionImageInterface $img */
        $img = $this->manager->read($sourcePath);
        $encoder = new \Intervention\Image\Encoders\WebpEncoder($quality);
        $encoded = (string) $img->encode($encoder);
        File::put($target, $encoded);

        return $target;
    }

    public function generatePublicDerivatives(string $sourcePath, string $hash): array
    {
        $this->assertImageAvailable();
        $quality = (int) config('uploads.quality', 85);
        $variants = (array) config('uploads.derivatives', []);
        $dir = $this->storage->publicHashDirectory($hash);
        $written = [];

        foreach ($variants as $variant => $options) {
            $variant = (string) $variant;
            $path = $dir . DIRECTORY_SEPARATOR . $variant . '.webp';

            /** @var InterventionImageInterface $img */
            $img = $this->manager->read($sourcePath);

            if (isset($options['size'])) {
                $size = (int) $options['size'];
                $out = $img->cover($size, $size);
            } else {
                $max = (int) ($options['max'] ?? 0);
                if ($max <= 0) {
                    $max = 2560;
                }

                $out = $img->scaleDown($max, $max);
            }

            $encoder = new \Intervention\Image\Encoders\WebpEncoder($quality);
            $encoded = (string) $out->encode($encoder);
            File::put($path, $encoded);
            $written[$variant] = $path;
        }

        return $written;
    }

    private function assertImageAvailable(): void
    {
        if (! $this->imageAvailable) {
            throw new RuntimeException('Intervention Image is not available.');
        }
    }
}