pronouns.cc/backend/routes/v2/auth/email_signup.go

package auth

import (
	"net/http"
	"strings"

	"codeberg.org/pronounscc/pronouns.cc/backend/common"
	"codeberg.org/pronounscc/pronouns.cc/backend/server"
	"emperror.dev/errors"
	"github.com/go-chi/render"
	"github.com/mediocregopher/radix/v4"
)

type postEmailSignupRequest struct {
	Email string `json:"email"`
}

func (s *Server) postEmailSignup(w http.ResponseWriter, r *http.Request) (err error) {
	ctx := r.Context()
	var req postEmailSignupRequest
	err = render.Decode(r, &req)
	if err != nil {
		return server.APIError{Code: server.ErrBadRequest}
	}

	if !strings.Contains(req.Email, "@") {
		return server.APIError{Code: server.ErrBadRequest, Details: "Email seems to be invalid"}
	}

	ticket := common.RandBase64(48)
	err = s.DB.Redis.Do(ctx, radix.Cmd(nil, "SET", emailSignupTicketKey(ticket), req.Email, "EX", "3600"))
	if err != nil {
		return errors.Wrap(err, "setting email signup key")
	}

	// if the email address already exists, pretend we sent an email and return
	// to prevent people from discovering valid email addresses
	exists, err := s.DB.EmailExists(ctx, req.Email)
	if err != nil {
		return errors.Wrap(err, "checking if email exists")
	}
	if exists {
		render.NoContent(w, r)
		return nil
	}

	go s.SendEmail(req.Email, "Confirm your email address", "signup", map[string]any{
		"ticket": ticket,
	})

	return nil
}

func emailSignupTicketKey(ticket string) string {
	return "email-signup:" + ticket
}