预订系统定价条件重构

Question

我做了一个有预订和保留的项目，一个客户有一个以前用Laravel/PHP完成的平台，并要求我们做一些修改。这是我第一次用算法计算日期范围内的价格，所以我试图猜测什么是最有效的方法。

现在，客户有4种不同的价格：

• 淡季(11月1日至3月31日)
• 中季(4月1日至6月30日和10月1日至10月31日)
• 高级季节(7月1日至7月15日和8月16日至30日(7月16日至8月15日)

)

在这几个季节里，他们有不同种类的汽车要租，但之前的代码太麻烦了，无法计算出合适的价格。以下是一段简短的节选：

$startDate = str_replace("/", "-", explode(' ', $request->startDate)[0]);
$endDate = str_replace("/", "-", explode(' ', $request->endDate)[0]);

$begin = new DateTime($startDate);
$end = new DateTime($endDate);
if ($startDate == $endDate) {
    $end->setTime(0, 0, 1);
}

$startYear = intval($begin->format('Y'));
$endYear = intval($end->format('Y'));

$interval = new DateInterval('P1D');
$daterange = new DatePeriod($begin, $interval, $end);

$groupPrices = DB::table("Group")->select("*")->get();
$totalGroupPrices = [];
$totalGroupPricesWithInsurance = [];

foreach ($groupPrices as $group) {
    foreach ($daterange as $date) {
        if ($date->format('d-m-Y') >= "1/11/" . strval($startYear) and $date->format('d-m-Y') <= "31/3/" . strval(($endYear + 1))) {
            (isset($totalGroupPrices[$group->id]) ? $totalGroupPrices[$group->id] += $group->lowSeasonPrice : $totalGroupPrices[$group->id] = $group->lowSeasonPrice);
            (isset($totalGroupPricesWithInsurance[$group->id]) ? $totalGroupPricesWithInsurance[$group->id] += $group->lowSeasonPriceWithInsurance : $totalGroupPricesWithInsurance[$group->id] = $group->lowSeasonPriceWithInsurance);
        } elseif ($date->format('d-m-Y') >= "1/1/" . strval($startYear) and $date->format('d-m-Y') <= "31/3/" . strval(($endYear))) {
            (isset($totalGroupPrices[$group->id]) ? $totalGroupPrices[$group->id] += $group->lowSeasonPrice : $totalGroupPrices[$group->id] = $group->lowSeasonPrice);
            (isset($totalGroupPricesWithInsurance[$group->id]) ? $totalGroupPricesWithInsurance[$group->id] += $group->lowSeasonPriceWithInsurance : $totalGroupPricesWithInsurance[$group->id] = $group->lowSeasonPriceWithInsurance);
        } elseif (($date->format('d-m') >= "1/4" and $date->format('d-m') <= "30/6") or ($date->format('d-m') >= "1/10" and $date->format('d-m') <= "31/10")) {
            (isset($totalGroupPrices[$group->id]) ? $totalGroupPrices[$group->id] += $group->mediumSeasonPrice : $totalGroupPrices[$group->id] = $group->mediumSeasonPrice);
            (isset($totalGroupPricesWithInsurance[$group->id]) ? $totalGroupPricesWithInsurance[$group->id] += $group->mediumSeasonPriceWithInsurance : $totalGroupPricesWithInsurance[$group->id] = $group->mediumSeasonPriceWithInsurance);
        } elseif (($date->format('d-m') >= "1/7" and $date->format('d-m') <= "15/7") or ($date->format('d-m') >= "16/8" and $date->format('d-m') <= "30/9")) {
            (isset($totalGroupPrices[$group->id]) ? $totalGroupPrices[$group->id] += $group->highSeasonPrice : $totalGroupPrices[$group->id] = $group->highSeasonPrice);
            (isset($totalGroupPricesWithInsurance[$group->id]) ? $totalGroupPricesWithInsurance[$group->id] += $group->highSeasonPriceWithInsurance : $totalGroupPricesWithInsurance[$group->id] = $group->highSeasonPriceWithInsurance);
        } elseif ($date->format('d-m') >= "16/7" and $date->format('d-m') <= "15/8") {
            (isset($totalGroupPrices[$group->id]) ? $totalGroupPrices[$group->id] += $group->peakSeasonPrice : $totalGroupPrices[$group->id] = $group->peakSeasonPrice);
            (isset($totalGroupPricesWithInsurance[$group->id]) ? $totalGroupPricesWithInsurance[$group->id] += $group->peakSeasonPriceWithInsurance : $totalGroupPricesWithInsurance[$group->id] = $group->peakSeasonPriceWithInsurance);
        }
    }
}

我确信这必须有一个非常简单的方法，或者至少用更少的代码来减少buggy。我只想知道你会如何设计这个算法。

提前谢谢。

Answer 1

就像这样：

private function season($date): string
{
    $seasons = [
        // items are month, day, duration.
        'medium' => [[4, 1, 90], [10, 1, 30]],
        'heigh' => [[7, 1, 14], [8, 16, 45]],
        'peak' => [[7, 16, 30]],
    ];

    $year = Carbon::now()->year;

    $date = Carbon::createFromDate($year, $date->month, $date->day);

    foreach ($seasons as $name => $periods) {
        foreach ($periods as $period) {
            $start = Carbon::createFromDate($year, $period[0], $period[1]);

            $end = $start->copy()->addDays($period[2]);

            if ($date->gt($start) && $date->lte($end)) return $name; 
        }
    }

    return 'low';
}

private function calculate($season, $group, $gp, $gpwi)
{
    $sp = "{$season}SeasonPrice";
    
    $spwi = "{$season}SeasonPriceWithInsurance";

    return [
        (isset($gp[$group->id]) ? $gp[$group->id] : 0) + $group->$sp,
        (isset($gpwi[$group->id]) ? $gpwi[$group->id] : 0) + $group->$spwi
    ];
}

private function makePrices()
{
    foreach ($groupPrices as $group) {
        foreach ($daterange as $date) {
            [$totalGroupPrices, $totalGroupPricesWithInsurance] = $this->calculate(
                $this->season($date),
                $group,
                $totalGroupPrices,
                $totalGroupPricesWithInsurance
            );
        }
    }
}