Create WebP Copy In WordPress

create-webp-copy-in-wp.php

<?php
function generate_webp_from_file($file, $compression_quality = 80) {
    // check if file exists
    if (!file_exists($file)) {
        return false;
    }

    // If output file already exists return path
    $output_file = $file . '.webp';
    if (file_exists($output_file)) {
        return $output_file;
    }

    $file_type = strtolower(pathinfo($file, PATHINFO_EXTENSION));
	
    if (function_exists('imagewebp')) {
        switch ($file_type) {
            case 'jpeg':
            case 'jpg':
                $image = imagecreatefromjpeg($file);
                break;

            case 'png':
                $image = imagecreatefrompng($file);
                imagepalettetotruecolor($image);
                imagealphablending($image, true);
                imagesavealpha($image, true);
                break;

            case 'gif':
                $image = imagecreatefromgif($file);
                break;
            default:
                return false;
        }

        // Save the image
        $result = imagewebp($image, $output_file, $compression_quality);
        if (false === $result) {
            return false;
        }

        // Free up memory
        imagedestroy($image);

        return $output_file;
    } elseif (class_exists('Imagick')) {
		if ($file_type !== 'png') {
			return false;	
		}
		
        $image = new Imagick();
        $image->readImage($file);

        if ($file_type === 'png') {
            $image->setImageFormat('webp');
            $image->setImageCompressionQuality($compression_quality);
            $image->setOption('webp:lossless', 'true');
        }

        $image->writeImage($output_file);
        return $output_file;
    }

    return false;
}

/**
 * Generate .webp copy from each size when an attachment is uploaded
 */
add_action( 'wp_generate_attachment_metadata', function( $meta, $id, $content ) {
	$upload_dir = wp_get_upload_dir()['basedir'] . '/';
	$file = $upload_dir . $meta['file'];
	generate_webp_from_file( $file );
	
	foreach( $meta['sizes'] as $key => $file ) {
		$path = wp_get_upload_dir()['path'] . '/' . $file['file'];
		generate_webp_from_file( $path );
	}
	return $meta;
}, 10, 3 );

/**
 * Delete the all .webp copies
 */
add_action( 'delete_attachment', function( $id, $post ) {
	$file = get_attached_file( $id );
	$original_webp = "$file.webp";
	if( file_exists( $original_webp ) ) {
		unlink( $original_webp );
	}
	
	$meta = wp_get_attachment_metadata( $id );
	foreach( $meta['sizes'] as $key => $file ) {
		$path = wp_get_upload_dir()['path'] . '/' . $file['file'];
		$webp_file = "$path.webp";
		if( file_exists( $webp_file ) ) {
			unlink( $webp_file );
		}
	}
}, 10, 2);

Excellent snippet - I have one request if possible:
The metadata is lost during the Imagick conversion —> p‬lease retain all metadata