<?php
namespace Aumframe\Kit;

if (!defined('ABSPATH')) {
    exit;
}

/**
 * Media inside a kit.
 *
 * Why it needs its own layer: images in a scene are hard-coded absolute URLs (an `Image`
 * node's `props.src` is a string, not an attachment ID). So a kit moved to another site still has
 * URLs pointing at the exporter's domain — the front end looks like "the images are all there" while
 * the buyer's site is in fact hot-linking our server, and the day we clean up, every image on their
 * site breaks at once.
 *
 * The solution is "register on export, rewrite on import": every URL pointing at this site's uploads
 * is collected into `media[]` with a stable id, and after import writes the files, the whole table is
 * rewritten old URL → new URL.
 *
 * The theme's demo manager did the same thing for "media URLs in theme settings have to follow the
 * domain" (`restore_settings_media_urls` / `extract_base_site_url`); this is the same idea extended
 * to scenes and custom fields.
 */
class Media
{
    /**
     * Find every image or media URL in a block of text that points at this site's uploads.
     *
     * It scans the JSON string directly rather than parsing the structure — an image URL can appear in
     * `props.src`, in a custom field, inside customCss's `url(...)`, or in theme settings, and hunting
     * structure by structure is guaranteed to miss one. Whatever is missed is a hot-linked image.
 */
    public static function scan(string $text): array
    {
        $base = self::uploads_base();
        if ($base === '') {
            return [];
        }

        // Slashes in JSON may be escaped, so both forms have to be recognised
        $needle = preg_quote($base, '#');
        $alt    = preg_quote(str_replace('/', '\\/', $base), '#');

        /*
         * Audio and archives too (2026-09-14, template #10): a download store's product files and per-row
         * sound previews are upload URLs like any image, and a URL the scan does not recognise is a file
         * that never enters the package — the exported kit installs with every download row pointing at the
         * author's server.
 */
        $re = '#(?:' . $needle . '|' . $alt . ')[^"\'\\\\)\s]+\.(?:jpe?g|png|gif|webp|avif|svg|mp4|webm|pdf|mp3|wav|ogg|m4a|flac|aiff?|zip)#i';
        preg_match_all($re, $text, $m);

        $out = [];
        foreach ($m[0] as $hit) {
            $out[] = self::normalize(str_replace('\\/', '/', $hit));
        }
        return array_values(array_unique($out));
    }

    /**
     * Normalise a thumbnail URL back to the original.
     *
     * `photo-1024x768.jpg` → `photo.jpg`. Required — the same image appears at several sizes
     * across a layout, and without normalising they are packaged as several different images. Worse,
     * the importing site's generated size suffixes need not match the exporter's (they depend on which
     * sizes the theme registers), so copying them across produces 404s. Only the original is written on
     * import, and WordPress regenerates the sizes itself.
 */
    public static function normalize(string $url): string
    {
        return preg_replace('#-\d+x\d+(\.[a-z0-9]+)$#i', '$1', $url) ?? $url;
    }

    /** A stable id: the filename. Unchanged across sites, and readable by people. */
    public static function id_for(string $url): string
    {
        $name = pathinfo(wp_parse_url($url, PHP_URL_PATH) ?: $url, PATHINFO_FILENAME);
        $id   = sanitize_title($name);
        return $id !== '' ? $id : 'media-' . substr(md5($url), 0, 8);
    }

    /** The uploads base URL. (A protocol-agnostic comparison would be sturdier, but this is kept as-is
     *  and the rewrite matches the whole string.) */
    public static function uploads_base(): string
    {
        $up = wp_get_upload_dir();
        return isset($up['baseurl']) ? rtrim((string) $up['baseurl'], '/') : '';
    }

    /** Find an attachment by URL, mainly to read its alt. Returns 0 when not found. */
    public static function attachment_id(string $url): int
    {
        $id = attachment_url_to_postid($url);
        return $id ? (int) $id : 0;
    }

    /**
     * One media record: `{id, alt, url}`.
     *
     * `alt` is written out even when empty — it is a required field, and a missing one has to be
     * visible in the walkthrough rather than quietly absent as a key. That is exactly how the ebike
     * site ended up with an empty alt on every image.
 */
    public static function record(string $url): array
    {
        $att = self::attachment_id($url);
        return [
            'id'  => self::id_for($url),
            'alt' => $att ? (string) get_post_meta($att, '_wp_attachment_image_alt', true) : '',
            'url' => $url,
        ];
    }
}