/**
 * Checks if an email address is valid.
 *
 * @param {string} email
 * @returns {boolean}
 *
 * @example
 * isValidEmail('test@example.com') // true
 */
export function isValidEmail(email = '') {
    const emailPattern = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
    return emailPattern.test(email)
}

/**
 * Validates Philippine mobile number format.
 *
 * Must start with 09 and contain exactly 11 digits.
 *
 * @param {string} mobile
 * @returns {boolean}
 *
 * @example
 * hasValidMobileFormat('09171234567') // true
 */
export function hasValidMobileFormat(mobile = '') {
    const pattern = /^09\d{9}$/
    return pattern.test(mobile)
}

/**
 * Checks whether a value is numeric.
 *
 * Accepts strings or numbers.
 * Rejects empty strings, whitespace, and NaN.
 *
 * @param {string|number} value
 * @returns {boolean}
 *
 * @example
 * isNumeric('123')   // true
 * isNumeric(45)      // true
 * isNumeric('12.3')  // true
 * isNumeric('')      // false
 * isNumeric(' ')     // false
 */
export function isNumeric(value) {
  if (value === null || value === undefined) return false
  if (typeof value === 'string' && value.trim() === '') return false
  return !Number.isNaN(Number(value))
}


/**
 * Checks whether a response is a "hash-like" string.
 * 
 * A valid hash is:
 * - not empty
 * - not `true`
 * - not numeric
 * - does not contain spaces
 * 
 * @param {*} response - The value to check
 * @returns {string|false} - Returns the string if it is a hash, otherwise false
 *
 * @example
 * isResponseAHash('abc123') // 'abc123'
 * isResponseAHash('123')    // false
 * isResponseAHash(true)     // false
 * isResponseAHash('hello world') // false
 */
export function isResponseAHash(response) {
  if (!response || response === true) return false

  const result = String(response)
  if (result.includes(' ') || !isNaN(result)) return false

  return result
}