<?php

namespace App\Support;

use App\Models\Activity;
use App\Models\StudyTour;
use App\Models\Venue;

/**
 * H5 活动列表/详情：封面与轮播展示规则（活动缺省则回退关联场馆）。
 */
final class ActivityH5View
{
    /**
     * 列表/详情头图：优先活动封面，无则场馆封面。
     */
    public static function listCover(Activity $a): ?string
    {
        $c = trim((string) ($a->cover_image ?? ''));
        if ($c !== '') {
            return $c;
        }

        $v = trim((string) ($a->venue?->cover_image ?? ''));

        return $v !== '' ? $v : null;
    }

    /**
     * 轮播素材：gallery_media（可含图片/视频）；为空时用封面图兜底。
     *
     * @return array<int, array{type: string, url: string}>
     */
    public static function buildGalleryCarousel(Venue|Activity|StudyTour $model): array
    {
        $items = [];
        $seen = [];

        foreach ($model->gallery_media ?? [] as $m) {
            if (! is_array($m)) {
                continue;
            }
            $url = trim((string) ($m['url'] ?? ''));
            if ($url === '' || isset($seen[$url])) {
                continue;
            }
            $type = $m['type'] ?? 'image';
            if (! in_array($type, ['image', 'video'], true)) {
                $type = 'image';
            }
            $seen[$url] = true;
            $items[] = ['type' => $type, 'url' => $url];
        }

        if ($items === [] && $model->cover_image) {
            $url = trim((string) $model->cover_image);
            if ($url !== '') {
                $items[] = ['type' => 'image', 'url' => $url];
            }
        }

        return $items;
    }

    /**
     * H5 轮播：优先活动上传的轮播/封面；皆无则用场馆轮播/封面。
     *
     * @return array<int, array{type: string, url: string}>
     */
    public static function buildActivityH5Carousel(Activity $a): array
    {
        $fromActivity = self::buildGalleryCarousel($a);
        if (count($fromActivity) > 0) {
            return $fromActivity;
        }
        if ($a->venue) {
            return self::buildGalleryCarousel($a->venue);
        }

        return [];
    }
}