メールを送るよ

sendContactMail.ts

import fetch from "node-fetch"
import { config } from "firebase-functions"
import { createTransport } from "nodemailer"

type GMailOAuth2Config = {
  user: string
  "client-id": string
  "client-secret": string
  "refresh-token": string
}

const gmailOAuth2Config = config().gmail as GMailOAuth2Config
const recaptchaV3secret = config().recaptcha.v3secret

async function isValidRecaptchaV3({
  secret,
  response,
}: {
  secret: string
  response: string
}): Promise<boolean> {
  if (!response || !secret) {
    return false
  }

  try {
    const res = await fetch(`https://www.google.com/recaptcha/api/siteverify`, {
      method: "post",
      headers: {
        Accept: "application/json",
        "Content-Type": "application/x-www-form-urlencoded; charset=utf-8",
      },
      body: `secret=${secret}&response=${response}`,
    })
    const json = await res.json()
    return !!json.success
  } catch {
    return false
  }
}

export const sendContactMail = async ({
  data,
}: {
  data: { recapchaToken: string; body: string }
}) => {
  if (
    await isValidRecaptchaV3({
      secret: recaptchaV3secret,
      response: data.recapchaToken,
    })
  ) {
    const transport = createTransport({
      host: "smtp.gmail.com",
      port: 465,
      secure: true,
      auth: {
        type: "OAuth2",
        user: gmailOAuth2Config.user,
        clientId: gmailOAuth2Config["client-id"],
        clientSecret: gmailOAuth2Config["client-secret"],
        refreshToken: gmailOAuth2Config["refresh-token"],
      },
    })
    try {
      await transport.sendMail({
        to: gmailOAuth2Config.user,
        subject: "おたよりフォームからのおたより",
        text: data.body,
      })
    } catch {
      throw "sendmail failed"
    }
  } else {
    throw "recaptcha invalid"
  }
}