/**
 * 解析首字母转大写
 * @param str 字符串 ab
 * @returns 结果 Ab
 */
export function parseFirstUpper(str: string): string {
  if (!str) return str;
  str = str.replace(/[^_\w]+/g, '');
  return str.substring(0, 1).toUpperCase() + str.substring(1);
}

/**
 * 解析首字母转小写
 * @param str 字符串 Ab
 * @returns 结果 ab
 */
export function parseFirstLower(str: string): string {
  if (!str) return str;
  str = str.replace(/[^_\w]+/g, '');
  return str.substring(0, 1).toLowerCase() + str.substring(1);
}

/**
 * 解析下划线转驼峰
 * @param str 字符串 a_b
 * @returns  驼峰风格 aB
 */
export function parseStrLineToHump(str: string): string {
  if (!str) return str;
  return str.replace(/_(\w)/g, (_item, letter) => letter.toUpperCase());
}

/**
 * 解析驼峰转下划线
 * @param str 字符串 aB
 * @returns  下划线风格 a_b
 */
export function parseStrHumpToLine(str: string): string {
  if (!str) return str;
  return str.replace(/([A-Z])/g, '_$1').toLowerCase();
}

/**
 * 对象的key值驼峰转下划线
 * @param obj 对象属性 字符数组orJSON对象
 * @returns 驼峰转下划线
 */
export function parseObjHumpToLine(obj: any): any {
  if (obj === null || obj === undefined) {
    return obj;
  }
  if (Array.isArray(obj)) {
    return obj.map(v => parseObjHumpToLine(v));
  }
  if (typeof obj === 'object') {
    Object.keys(obj).forEach(key => {
      const new_key = parseStrHumpToLine(key);
      if (new_key !== key) {
        obj[new_key] = obj[key];
        delete obj[key];
      }
      obj[new_key] = parseObjHumpToLine(obj[new_key]);
    });
    return obj;
  }
  return obj;
}

/**
 * 对象的key值下划线转驼峰
 * @param obj 对象属性 字符数组orJSON对象
 * @returns 下划线转驼峰
 */
export function parseObjLineToHump(obj: any): any {
  if (obj === null || obj === undefined) {
    return obj;
  }
  if (Array.isArray(obj)) {
    return obj.map(v => parseObjLineToHump(v));
  }
  if (typeof obj === 'object') {
    Object.keys(obj).forEach(key => {
      const new_key = parseStrLineToHump(key);
      if (new_key !== key) {
        obj[new_key] = obj[key];
        delete obj[key];
      }
      obj[new_key] = parseObjLineToHump(obj[new_key]);
    });
    return obj;
  }
  return obj;
}