PHP函数重构实践：优化条件逻辑与提升可维护性

protected function execute(InputInterface $input, OutputInterface $output): int
{
    $this->setDrinkType($input);

    if (in_array($this->drinkType, $this->allowedDrinkTypes)) {
        // ... switch 语句处理饮品成本 ...
        switch ($this->drinkType) {
            case 'tea':
                if ($money < 0.4) {
                    $output->writeln('The tea costs 0.4');
                    return 0;
                }
                break;
            case 'coffee':
                if ($money < 0.5) {
                    $output->writeln('The coffee costs 0.5');
                    return 0;
                }
                break;
            case 'chocolate':
                if ($money < 0.6) {
                    $output->writeln('The chocolate costs 0.6');
                    return 0;
                }
                break;
        }
        if ($this->hasCorrectSugars($input)) {
            $this->checkSugars($input, $output);
            return 0;
        }
        $output->writeln('The number of sugars should be between 0 and 2');
        return 0;
    }
    $output->writeln('The drink type should be tea, coffee or chocolate');
    return 0;
}

// 定义饮品成本映射，这可以是一个类成员变量或从配置中加载
protected array $drinkCosts = [
    'tea' => 0.4,
    'coffee' => 0.5,
    'chocolate' => 0.6
];

// 在 execute 函数中
// ...
$money = $input->getArgument('money');
$drinkCost = $this->drinkCosts[$this->drinkType]; // 直接通过饮品类型获取成本

if ($money < $drinkCost) {
    $output->writeln('The ' . $this->drinkType . ' costs ' . $drinkCost);
    return 0;
}
// ...

if (in_array($this->drinkType, $this->allowedDrinkTypes)) {
    // ... 大量逻辑 ...
} else {
    $output->writeln('The drink type should be tea, coffee or chocolate');
    return 0;
}

if (!in_array($this->drinkType, $this->allowedDrinkTypes)) {
    $output->writeln('The drink type should be tea, coffee or chocolate');
    return 0; // 不符合条件，立即返回
}
// 只有当饮品类型合法时，才继续执行后续逻辑

// 金额检查
if ($money < $drinkCost) {
    $output->writeln('The ' . $this->drinkType . ' costs ' . $drinkCost);
    return 0;
}

// 糖量检查
if (!$this->hasCorrectSugars($input)) {
    $output->writeln('The number of sugars should be between 0 and 2');
    return 0;
}

use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class OrderProcessor // 假设这是包含这些方法的类
{
    protected string $drinkType;
    protected array $allowedDrinkTypes = ['tea', 'coffee', 'chocolate'];
    protected float $minSugars = 0;
    protected float $maxSugars = 2;

    // 饮品成本映射，可以作为类属性或通过构造函数注入
    protected array $drinkCosts = [
        'tea' => 0.4,
        'coffee' => 0.5,
        'chocolate' => 0.6
    ];

    // 假设 setDrinkType 方法已存在并设置 $this->drinkType
    protected function setDrinkType(InputInterface $input): void
    {
        $this->drinkType = $input->getArgument('drinkType'); // 示例：从输入获取饮品类型
    }

    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        $this->setDrinkType($input);

        // 1. 验证饮品类型 - 卫语句
        if (!in_array($this->drinkType, $this->allowedDrinkTypes)) {
            $output->writeln('The drink type should be tea, coffee or chocolate');
            return 0; // 假设0代表失败或退出
        }

        // 2. 获取饮品成本并验证金额 - 消除switch，使用数据映射和卫语句
        $money = $input->getArgument('money');
        $drinkCost = $this->drinkCosts[$this->drinkType];

        if ($money < $drinkCost) {
            $output->writeln('The ' . $this->drinkType . ' costs ' . $drinkCost);
            return 0;
        }

        // 3. 验证糖量 - 卫语句
        if (!$this->hasCorrectSugars($input)) {
            $output->writeln('The number of sugars should be between 0 and 2');
            return 0;
        }

        // 4. 处理并输出糖量信息
        $this->checkSugars($input, $output);

        // 假设0代表成功
        return 0;
    }

    protected function hasCorrectSugars(InputInterface $input): bool
    {
        $sugars = $input->getArgument('sugars');
        return ($sugars >= $this->minSugars && $sugars <= $this->maxSugars);
    }

    protected function checkSugars(InputInterface $input, OutputInterface $output): void
    {
        $sugars = $input->getArgument('sugars');

        $output->write('You have ordered a ' . $this->drinkType);
        // 假设 isExtraHot 方法存在并被调用
        // $this->isExtraHot($input, $output);
        $output->write(' with ' . $sugars . ' sugars');
        if ($sugars > 0) {
            $output->write(' (stick included)');
        }
        $output->writeln('');
    }
}