// Put this wherever you like; it just needs to run early enough to hook 
// into these filters.

function encode_commas($string)
{
    return str_replace(',', '%2C', $string);
}

/**
 * Put Cloudinary URL generation in one place.
 *
 * @param       $url
 * @param array $options
 *
 * @return bool|mixed|string|string[]|null
 */
function rewrite_for_cl($url, array $options = [])
{
    // The env var here is the Cloudinary API url you can get in the dashboard.
    // It looks something like this:
    // cloudinary://24927894590:b0982nv0su903h89ufhjkfdvnsd@accountname
    $cl_folder = env('development') ? 'testing' : 'images';

    $cl_options = array_merge([
        'quality' => 'auto',
        'resource_type' => 'image',
        'fetch_format' => 'auto',
        'dpr' => 'auto',
    ], $options);

    $wp_upload_dir = wp_get_upload_dir();
    $to_remove = $wp_upload_dir['baseurl'] ?? false;

    if ($to_remove) {
        // Normalize protocol
        $url = str_replace(['https', 'http'], '', $url);
        $to_remove = str_replace(['https', 'http'], '', $to_remove);

        // Turn our local url into our cloudinary directory
        $image_url = str_replace($to_remove, $cl_folder, $url);

        // Encode commas so that Lozad doesn't freak out
        $image_url = encode_commas($image_url);

        return cloudinary_url($image_url, $cl_options);
    }

    return false;
}

/**
 * Filter image sources and rewrite them to cloudinary URLs if possible.
 */
add_filter('wp_get_attachment_image_src', function($image) {
    if ($image && filter_var($image[0], FILTER_VALIDATE_URL)) {
        if ($cl_url = rewrite_for_cl($image[0])) {
            $image[0] = $cl_url;
        }
    }
    return $image;
}, 10, 1);

/**
 * Filter srcsets and rewrite them to cloudinary URLs if possible.
 */
add_filter('wp_calculate_image_srcset', function($sources) {
    foreach ($sources as &$source) {
        if($cl_url = rewrite_for_cl($source['url'])) {
             $source['url'] = encode_commas($cl_url);
        }
    }
    return $sources;
}, 10, 1);