<?php

declare(strict_types=1);

namespace App\Libraries\Pipeline;

/**
 * Image driver — GD-based (jpg/png/webp/avif where the build supports
 * it), with ImageMagick as a fallback for exotic formats. Re-encoding
 * doubles as metadata stripping.
 */
final class Images implements DriverInterface
{
    public function handle(array $job, array $tool, callable $update): array
    {
        $input  = Ffmpeg::resolveInput($job);
        $params = json_decode($job['params'] ?? '{}', true) ?: [];
        $update(10, 'processing');

        $image = imagecreatefromstring((string) file_get_contents($input));
        if ($image === false) {
            throw new \RuntimeException('The file could not be read as an image.');
        }

        // preserve orientation of JPEGs
        $exif = @exif_read_data($input);
        if ($exif !== false && isset($exif['Orientation'])) {
            $angle = match ((int) $exif['Orientation']) {
                3 => 180, 6 => -90, 8 => 90, default => null,
            };
            if ($angle !== null) {
                $image = imagerotate($image, $angle, 0);
            }
        }
        if (function_exists('imagepalettetotruecolor')) {
            imagepalettetotruecolor($image);
        }
        imagealphablending($image, true);
        imagesavealpha($image, true);

        // resize / crop before encoding
        $w = imagesx($image);
        $h = imagesy($image);
        if (! empty($params['width']) || ! empty($params['height'])) {
            [$nw, $nh] = $this->fitSize($w, $h, (int) ($params['width'] ?? 0), (int) ($params['height'] ?? 0));
            $scaled = imagecreatetruecolor(max(1, $nw), max(1, $nh));
            imagealphablending($scaled, false);
            imagesavealpha($scaled, true);
            imagecopyresampled($scaled, $image, 0, 0, 0, 0, $nw, $nh, $w, $h);
            imagedestroy($image);
            $image = $scaled;
            $update(55, 'resizing');
        }
        if (! empty($params['crop_width']) && ! empty($params['crop_height'])) {
            $cw = min(imagesx($image), (int) $params['crop_width']);
            $ch = min(imagesy($image), (int) $params['crop_height']);
            $cx = max(0, min(imagesx($image) - $cw, (int) ($params['crop_x'] ?? 0)));
            $cy = max(0, min(imagesy($image) - $ch, (int) ($params['crop_y'] ?? 0)));
            $cropped = imagecreatetruecolor($cw, $ch);
            imagealphablending($cropped, false);
            imagesavealpha($cropped, true);
            imagecopy($cropped, $image, 0, 0, $cx, $cy, $cw, $ch);
            imagedestroy($image);
            $image = $cropped;
            $update(70, 'cropping');
        }
        if (($params['rotate'] ?? 0) != 0) {
            $deg   = in_array(abs((int) $params['rotate']), [90, 180, 270], true) ? (int) $params['rotate'] : 90;
            $image = imagerotate($image, -$deg, 0); // GD rotates counter-clockwise
            $update(70, 'rotating');
        }
        if (! empty($params['flip'])) {
            imageflip($image, $params['flip'] === 'vertical' ? IMG_FLIP_VERTICAL : IMG_FLIP_HORIZONTAL);
        }

        $ext = strtolower((string) ($params['format'] ?? $tool['primary_output_format'] ?? pathinfo($job['input_file'], PATHINFO_EXTENSION)));
        if ($ext === 'jpeg') {
            $ext = 'jpg';
        }
        $quality = (int) max(30, min(100, (int) ($params['quality'] ?? 85)));

        [, $out] = $this->outputPath($job, $ext);

        $ok = match ($ext) {
            'jpg'  => imagejpeg($image, $out, $quality),
            'png'  => imagepng($image, $out, (int) round(9 * (1 - $quality / 100))),
            'webp' => function_exists('imagewebp') ? imagewebp($image, $out, $quality) : false,
            'avif' => function_exists('imageavif') ? imageavif($image, $out, $quality) : false,
            'gif'  => imagegif($image, $out),
            default => throw new \RuntimeException("Format {$ext} is not supported."),
        };
        imagedestroy($image);
        if (! $ok) {
            throw new \RuntimeException("Saving as {$ext} is not supported by this server.");
        }
        $update(95, 'finalizing');

        return ['file' => basename($out), 'name' => $this->downloadName($job, $ext), 'ext' => $ext];
    }

    private function fitSize(int $w, int $h, int $targetW, int $targetH): array
    {
        if ($targetW > 0 && $targetH > 0) {
            return [min($targetW, $w * 4), min($targetH, $h * 4)];
        }
        if ($targetW > 0) {
            return [$targetW, max(1, (int) round($h * $targetW / $w))];
        }

        return [max(1, (int) round($w * $targetH / $h)), $targetH];
    }

    private function outputPath(array $job, string $ext): array
    {
        $file = \App\Libraries\Pipeline::safeName($job['id'], $ext);

        return [$file, \App\Libraries\Pipeline::storageDir() . '/' . $file];
    }

    private function downloadName(array $job, string $ext): string
    {
        $base = preg_replace('/[^A-Za-z0-9 _.-]/u', '_', pathinfo((string) ($job['input_name'] ?? 'image'), PATHINFO_FILENAME)) ?: 'image';

        return mb_substr($base, 0, 80) . '.' . $ext;
    }
}