package service

import (
	"context"
	"errors"
	"sync"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"

	"laic-backend/service/smsrpc"
)

const (
	smsRequestTimeout   = time.Second
	smsLoginTemplateID  = "SMS_73670083"
	smsRegisterTemplate = "SMS_73670081"
)

type smsTemplate struct {
	verifyType int32
	id         string
}

var smsTemplates = map[string]smsTemplate{
	"login":    {verifyType: 1, id: smsLoginTemplateID},
	"register": {verifyType: 2, id: smsRegisterTemplate},
	"reset":    {verifyType: 1, id: smsLoginTemplateID},
}

type smsRPCClient struct {
	mu    sync.Mutex
	url   string
	conn  *grpc.ClientConn
	close func() error
}

var defaultSMSRPCClient smsRPCClient

func sendSMS(url, scene, phone, code string) error {
	template, ok := smsTemplates[scene]
	if !ok || url == "" {
		return errors.New("短信服务配置错误")
	}

	client, err := defaultSMSRPCClient.client(url)
	if err != nil {
		return err
	}

	ctx, cancel := context.WithTimeout(context.Background(), smsRequestTimeout)
	defer cancel()

	result, err := client.SendSms(ctx, &message.SmsRequest{
		VerifyCode: code,
		VerifyType: template.verifyType,
		SmsId:      template.id,
		Phone:      phone,
	})
	if err != nil || result == nil || !result.Value {
		return errors.New("短信发送失败")
	}
	return nil
}

func (c *smsRPCClient) client(url string) (message.SmsClient, error) {
	c.mu.Lock()
	defer c.mu.Unlock()

	if c.conn != nil && c.url == url {
		return message.NewSmsClient(c.conn), nil
	}
	if c.close != nil {
		_ = c.close()
	}

	conn, err := grpc.NewClient(url, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, err
	}
	c.url = url
	c.conn = conn
	c.close = conn.Close
	return message.NewSmsClient(conn), nil
}