<?php

namespace App\Services;

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

/** Preserve the monetary budget behavior for activities created before quotas. */
class ActivityBudgetService
{
    public static function award(ActivityReward $activity, $amount, callable $grant): bool
    {
        if (!is_numeric($amount) || !preg_match('/^\d{1,12}(\.\d{1,2})?$/', (string)$amount)
            || bccomp((string)$amount, '0', 2) <= 0) {
            return false;
        }
        return DB::transaction(function () use ($activity, $amount, $grant) {
            $locked = ActivityReward::where('id', $activity->id)->lockForUpdate()->first();
            if (!$locked) return false;
            if ((int)$locked->type === 2) {
                $grant();
                return true;
            }
            $used = bcadd((string)($locked->budget_used ?? '0'), (string)$amount, 2);
            if ($locked->budget !== null && bccomp($used, (string)$locked->budget, 2) > 0) return false;
            $grant();
            $locked->budget_used = $used;
            $locked->save();
            return true;
        });
    }
}