package sanitizer

import (
	"strings"
)

// SensitiveFields 敏感字段列表
var SensitiveFields = []string{
	"password", " Password", "pwd",
	"token", "access_token", "refresh_token", "Token",
	"secret", "Secret", "api_key", "apiKey", "secret_key",
	"id_card", "idCard", "身份证",
	"phone", "mobile", "Phone", "Mobile", "手机号",
	"email", "Email", "邮箱",
	"bank_card", "bankCard", "银行卡",
	"credit_card", "信用卡",
	"address", "Address", "详细地址",
	"real_name", "realName", "真实姓名",
}

// SkipMaskFields 不需要脱敏的字段
var SkipMaskFields = []string{
	"avatar", "nickname", "username", "content", "title", "description",
}

// MaskValue 根据字段名脱敏处理
func MaskValue(field, value string) string {
	if value == "" {
		return ""
	}

	fieldLower := strings.ToLower(field)

	// 检查是否跳过脱敏
	for _, f := range SkipMaskFields {
		if fieldLower == f || strings.HasSuffix(fieldLower, f) {
			return value
		}
	}

	// 根据字段类型脱敏
	switch {
	case strings.Contains(fieldLower, "phone"):
		return maskPhone(value)
	case strings.Contains(fieldLower, "email"):
		return maskEmail(value)
	case strings.Contains(fieldLower, "id_card"):
		return maskIDCard(value)
	case strings.Contains(fieldLower, "bank_card") || strings.Contains(fieldLower, "credit_card"):
		return maskBankCard(value)
	case strings.Contains(fieldLower, "token") || strings.Contains(fieldLower, "secret") || strings.Contains(fieldLower, "api_key"):
		return "***"
	case fieldLower == "password" || fieldLower == "pwd":
		return "***"
	case strings.Contains(fieldLower, "address"):
		return maskAddress(value)
	case strings.Contains(fieldLower, "real_name"):
		return maskName(value)
	default:
		return value
	}
}

// maskPhone 手机号脱敏（保留前3后4）
func maskPhone(s string) string {
	if len(s) == 11 {
		return s[:3] + "****" + s[7:]
	}
	return "***"
}

// maskEmail 邮箱脱敏（保留前2）
func maskEmail(s string) string {
	parts := strings.Split(s, "@")
	if len(parts) == 2 && len(parts[0]) > 2 {
		return parts[0][:2] + "***@" + parts[1]
	}
	return "***"
}

// maskIDCard 身份证脱敏（保留前6后4）
func maskIDCard(s string) string {
	if len(s) == 18 {
		return s[:6] + "********" + s[14:]
	}
	if len(s) == 15 {
		return s[:6] + "*****" + s[11:]
	}
	return "***"
}

// maskBankCard 银行卡号脱敏（保留前4后4）
func maskBankCard(s string) string {
	length := len(s)
	if length >= 8 {
		return s[:4] + "****" + s[length-4:]
	}
	return "***"
}

// maskAddress 地址脱敏（只显示省市）
func maskAddress(s string) string {
	parts := strings.Split(s, "省")
	if len(parts) > 1 {
		cityParts := strings.Split(parts[1], "市")
		if len(cityParts) > 1 {
			return parts[0] + "省" + cityParts[0] + "市****"
		}
		return parts[0] + "省****"
	}
	return "***"
}

// maskName 姓名脱敏（保留姓氏）
func maskName(s string) string {
	runes := []rune(s)
	length := len(runes)
	if length == 0 {
		return ""
	}
	if length == 2 {
		return string(runes[0]) + "*"
	}
	if length >= 3 {
		return string(runes[0]) + "*" + string(runes[length-1:])
	}
	return "*"
}

// IsSensitiveField 判断字段是否为敏感字段
func IsSensitiveField(field string) bool {
	fieldLower := strings.ToLower(field)
	for _, f := range SensitiveFields {
		if strings.Contains(fieldLower, f) {
			return true
		}
	}
	return false
}