package sms

import (
	"fmt"

	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common"
	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common/profile"
	tencentSms "github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/sms/v20210111"

	"gotest/internal/config"
)

// TencentSender 腾讯云短信发送器
type TencentSender struct {
	secretID   string
	secretKey  string
	signName   string
	templateID string
	appID      string
	client     *tencentSms.Client
}

// NewTencentSender 根据腾讯云短信配置创建发送器实例
func NewTencentSender(cfg *config.TencentSMS) *TencentSender {
	return &TencentSender{
		secretID:   cfg.SecretID,
		secretKey:  cfg.SecretKey,
		signName:   cfg.SignName,
		templateID: cfg.TemplateID,
		appID:      cfg.AppID,
	}
}

// Send 通过腾讯云短信服务发送验证码
func (s *TencentSender) Send(phone string, code string) error {
	// 关键配置校验，SecretID/SecretKey 为空时直接返回错误
	if s.secretID == "" || s.secretKey == "" {
		return fmt.Errorf("腾讯云短信未配置: SecretID/SecretKey 不能为空")
	}

	// 懒加载客户端，避免构造时因配置缺失直接 panic
	if s.client == nil {
		credential := common.NewCredential(s.secretID, s.secretKey)
		cpf := profile.NewClientProfile()
		// 短信服务默认使用 ap-guangzhou 区域
		client, err := tencentSms.NewClient(credential, "ap-guangzhou", cpf)
		if err != nil {
			return fmt.Errorf("创建腾讯云短信客户端失败: %w", err)
		}
		s.client = client
	}

	// 构造发送请求
	// 腾讯云要求手机号带国家码，默认拼接 +86
	req := tencentSms.NewSendSmsRequest()
	req.SmsSdkAppId = common.StringPtr(s.appID)
	req.SignName = common.StringPtr(s.signName)
	req.TemplateId = common.StringPtr(s.templateID)
	req.TemplateParamSet = common.StringPtrs([]string{code})
	req.PhoneNumberSet = common.StringPtrs([]string{"+86" + phone})

	// 调用腾讯云短信接口发送
	resp, err := s.client.SendSms(req)
	if err != nil {
		return fmt.Errorf("腾讯云短信发送失败: %w", err)
	}

	// 校验业务返回码，SendStatusSet 中第一条记录的 Code 为 "Ok" 表示发送成功
	if resp.Response == nil || len(resp.Response.SendStatusSet) == 0 {
		return fmt.Errorf("腾讯云短信发送失败: 无返回结果")
	}
	status := resp.Response.SendStatusSet[0]
	if status.Code == nil || *status.Code != "Ok" {
		errMsg := "未知错误"
		if status.Message != nil {
			errMsg = *status.Message
		}
		return fmt.Errorf("腾讯云短信发送失败: %s", errMsg)
	}

	return nil
}