/// 参数装饰器

import 'reflect-metadata';

const requiredKey = Symbol('paramsIndexs');

function required(
  target, // 对于静态成员来说是类的构造器，对于实例成员来说是类的原型链
  methodName: string, // 方法名称
  parameterIndex: number // 描述符
) {
  console.info({ target, methodName, parameterIndex });

  // 将参数下标信息存入元数据中
  const requiredList: number[] =
    Reflect.getOwnMetadata(requiredKey, target, methodName) || [];
  requiredList.push(parameterIndex);
  Reflect.defineMetadata(requiredKey, requiredList, target, methodName);
}

const isStringKey = Symbol('isStringKey');

function isString(target, methodName, parameterIndex) {
  const isStringList: number[] =
    Reflect.getOwnMetadata(isStringKey, target, methodName) || [];
  isStringList.push(parameterIndex);
  Reflect.defineMetadata(isStringKey, isStringList, target, methodName);
}

function validate(
  target,
  methodName,
  // eslint-disable-next-line @typescript-eslint/ban-types
  descriptor: TypedPropertyDescriptor<Function>
) {
  const requiredList =
    Reflect.getMetadata(requiredKey, target, methodName) || [];
  const isStringList =
    Reflect.getMetadata(isStringKey, target, methodName) || [];

  console.info({ requiredList });

  const oldValue = descriptor.value;
  descriptor.value = function (...args) {
    args.forEach((arg, i) => {
      if (requiredList.includes(i) && arg === undefined) {
        throw Error(`第${i + 1}个参数为必选`);
      }
      if (isStringList.includes(i) && typeof arg !== 'string') {
        throw Error(`第${i + 1}个参数必须为字符串`);
      }
    });

    return oldValue.apply(this, args);
  };
}

class Animal {
  @validate
  call(@required message, @isString code) {
    console.log('~~');
  }

  @validate
  static call(@isString message, @required code) {
    console.log('~~');
  }
}

const ani = new Animal();

try {
  ani.call('22', undefined);
  Animal.call('aa', '22');
} catch (err) {
  console.info(err.message);
}

export default Animal;