<?php

namespace App\Services;

use App\Models\Banner;
use Illuminate\Support\Facades\DB;

class BannerVisibilityService
{
    /** Positive numeric links are activity IDs; empty/zero and other links are unbound. */
    public static function activityId($link): ?string
    {
        $link = trim((string) $link);
        if ($link === '' || !ctype_digit($link)) {
            return null;
        }

        $id = ltrim($link, '0');
        return $id === '' ? null : $id;
    }

    /** Bound banners follow the activity; only unbound banners use the stored manual setting. */
    public static function decorate(iterable $banners, ?int $now = null): array
    {
        $now = $now ?? time();
        $items = [];
        $activityIds = [];
        foreach ($banners as $banner) {
            $item = $banner instanceof Banner ? $banner->toArray() : $banner;
            $item['status'] = (int) $item['status'];
            $item['activity_id'] = self::activityId($item['link'] ?? null);
            $item['can_manual_toggle'] = $item['activity_id'] === null;
            $item['manual_status'] = $item['can_manual_toggle'] ? $item['status'] : null;
            if ($item['activity_id'] !== null) {
                $activityIds[$item['activity_id']] = $item['activity_id'];
            }
            $items[] = $item;
        }

        // Read raw timestamps; ActivityReward's date accessors discard the time of day.
        $activities = empty($activityIds) ? collect() : DB::table('activity_rewards')
            ->whereIn('id', array_values($activityIds))
            ->get(['id', 'status', 'start_time', 'end_time'])->keyBy('id');

        foreach ($items as &$item) {
            $activity = $item['activity_id'] === null ? null : $activities->get($item['activity_id']);
            $reason = null;
            if ($item['activity_id'] !== null) {
                if ($activity === null) {
                    $reason = 'activity_missing';
                } elseif ((int) $activity->status !== 1) {
                    $reason = 'activity_offline';
                } elseif ((int) $activity->start_time > $now) {
                    $reason = 'activity_not_started';
                } elseif ((int) $activity->end_time <= $now) {
                    $reason = 'activity_ended';
                }
            } elseif ($item['manual_status'] !== 1) {
                $reason = 'manual';
            }
            $item['effective_status'] = $reason === null ? 1 : 0;
            $item['status'] = $item['effective_status'];
            $item['offline_reason'] = $reason;
        }
        unset($item);

        return $items;
    }
}