import Foundation

struct ValidationHelper {
    
    /// 验证邮箱地址格式是否正确
    /// - Parameter email: 邮箱地址
    /// - Returns: 是否为有效的邮箱格式
    static func isValidEmail(_ email: String) -> Bool {
        let emailRegex = "^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}$"
        let emailPredicate = NSPredicate(format: "SELF MATCHES %@", emailRegex)
        return emailPredicate.evaluate(with: email)
    }
    
    /// 验证手机号码格式是否正确（中国大陆）
    /// - Parameter phoneNumber: 手机号码
    /// - Returns: 是否为有效的手机号格式
    static func isValidPhoneNumber(_ phoneNumber: String) -> Bool {
        let phoneRegex = "^1[3-9]\\d{9}$"
        let phonePredicate = NSPredicate(format: "SELF MATCHES %@", phoneRegex)
        return phonePredicate.evaluate(with: phoneNumber)
    }
    
    /// 验证密码强度
    /// - Parameter password: 密码
    /// - Returns: 是否满足密码强度要求（6-16位，包含字母和数字）
    static func isValidPassword(_ password: String) -> Bool {
        guard password.count >= 6 && password.count <= 16 else { return false }
        let hasLetter = password.rangeOfCharacter(from: .letters) != nil
        let hasNumber = password.rangeOfCharacter(from: .decimalDigits) != nil
        return hasLetter && hasNumber
    }
    
    /// 验证验证码格式
    /// - Parameter code: 验证码
    /// - Returns: 是否为有效的验证码格式（4-6位数字）
    static func isValidVerificationCode(_ code: String) -> Bool {
        let codeRegex = "^\\d{4,6}$"
        let codePredicate = NSPredicate(format: "SELF MATCHES %@", codeRegex)
        return codePredicate.evaluate(with: code)
    }
}