package email

import (
	"errors"
	"fmt"
	"strings"

	"yunyan/lego/sys/log"
	"yunyan/lego/utils/mapstructure"
)

type EmailType uint8

const (
	QQEmail      EmailType = iota //QQ邮箱
	TencentEmail                  //腾讯企业邮箱
	GmailEmail                    //Google邮箱
	ResendEmail                   //Resend（HTTP API 发信，海外送达率优，Password 字段填 API Key）

)

type Option func(*Options)
type Options struct {
	EmailType EmailType
	FromEmail string
	FromName  string
	Password  string
}

func Set_EmailType(v EmailType) Option {
	return func(o *Options) {
		o.EmailType = v
	}
}

func Set_FromEmail(v string) Option {
	return func(o *Options) {
		o.FromEmail = v
	}
}
func Set_FromName(v string) Option {
	return func(o *Options) {
		o.FromName = v
	}
}
func Set_Password(v string) Option {
	return func(o *Options) {
		o.Password = v
	}
}

func newOptions(config map[string]interface{}, opts ...Option) Options {
	options := Options{}
	if config != nil {
		mapstructure.Decode(config, &options)
	}
	for _, o := range opts {
		o(&options)
	}
	if options.FromEmail == "" || options.Password == "" {
		log.Panicf("start email Missing necessary configuration : Serverhost:%s Fromemail:%s Fompasswd:%s", options.FromEmail, options.EmailType)
	}
	return options
}

func newOptionsByOption(opts ...Option) Options {
	options := Options{}
	for _, o := range opts {
		o(&options)
	}
	if options.FromEmail == "" || options.Password == "" {
		log.Panicf("start email Missing necessary configuration : Serverhost:%s Fromemail:%s Fompasswd:%s", options.FromEmail, options.EmailType)
	}
	return options
}

// validate 校验发信必需字段。
// FromEmail 必须是「邮箱地址」而非域名：SMTP 与 Resend 的 from 都要求 name@domain 形式，
// 只填域名（如 mail.example.com）会被 Resend 以 422 validation_error 拒绝。
func (o Options) validate() error {
	if o.FromEmail == "" {
		return errors.New("email 配置缺失: FromEmail 为空")
	}
	if o.Password == "" {
		return errors.New("email 配置缺失: Password 为空（SMTP 授权码 / Resend API Key）")
	}
	if !strings.Contains(o.FromEmail, "@") {
		return fmt.Errorf("email 配置错误: FromEmail=%q 是域名不是邮箱地址（应形如 noreply@%s）", o.FromEmail, o.FromEmail)
	}
	return nil
}

// newOptionsChecked 与 newOptions 同构，但配置不合法时返回 error 而非 panic。
// 供运行时热重载(Reload)使用：后台一次误保存只应让本次重载失败，不该打挂线上进程。
func newOptionsChecked(config map[string]interface{}, opts ...Option) (Options, error) {
	options := Options{}
	if config != nil {
		mapstructure.Decode(config, &options)
	}
	for _, o := range opts {
		o(&options)
	}
	return options, options.validate()
}