From a455c0186f5ed71813c4bf2350b62cf220b888d5 Mon Sep 17 00:00:00 2001
From: tsmethurst <tobi.smethurst@klarrio.com>
Date: Sun, 17 Oct 2021 15:25:20 +0200
Subject: [PATCH] SendConfirmEmail function

---
 internal/processing/user/emailconfirm.go | 78 ++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 internal/processing/user/emailconfirm.go

diff --git a/internal/processing/user/emailconfirm.go b/internal/processing/user/emailconfirm.go
new file mode 100644
index 000000000..2a68ddd7a
--- /dev/null
+++ b/internal/processing/user/emailconfirm.go
@@ -0,0 +1,78 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package user
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/email"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+)
+
+func (p *processor) SendConfirmEmail(ctx context.Context, user *gtsmodel.User, username string) error {
+	if user.UnconfirmedEmail == user.Email {
+		// user has already confirmed this email address, so there's nothing to do
+		return nil
+	}
+
+	// We need a token and a link for the user to click on.
+	// We'll use a uuid as our token since it's basically impossible to guess.
+	// From the uuid package we use (which uses crypto/rand under the hood):
+	//      Randomly generated UUIDs have 122 random bits.  One's annual risk of being
+	//      hit by a meteorite is estimated to be one chance in 17 billion, that
+	//      means the probability is about 0.00000000006 (6 × 10−11),
+	//      equivalent to the odds of creating a few tens of trillions of UUIDs in a
+	//      year and having one duplicate.
+	confirmationToken := uuid.NewString()
+	confirmationLink := util.GenerateURIForEmailConfirm(p.config.Protocol, p.config.Host, confirmationToken)
+
+	// pull our instance entry from the database so we can greet the user nicely in the email
+	instance := &gtsmodel.Instance{}
+	if err := p.db.GetWhere(ctx, []db.Where{{Key: "domain", Value: p.config.Host}}, instance); err != nil {
+		return fmt.Errorf("SendConfirmEmail: error getting instance: %s", err)
+	}
+
+	// assemble the email contents and send the email
+	confirmData := email.ConfirmData{
+		Username:     username,
+		InstanceURL:  instance.URI,
+		InstanceName: instance.Title,
+		ConfirmLink:  confirmationLink,
+	}
+	if err := p.emailSender.SendConfirmEmail(user.Email, confirmData); err != nil {
+		return fmt.Errorf("SendConfirmEmail: error sending to email address %s belonging to user %s: %s", user.Email, username, err)
+	}
+
+	// email sent, now we need to update the user entry with the token we just sent them
+	user.ConfirmationSentAt = time.Now()
+	user.ConfirmationToken = confirmationToken
+	user.LastEmailedAt = time.Now()
+	user.UpdatedAt = time.Now()
+
+	if err := p.db.UpdateByPrimaryKey(ctx, user); err != nil {
+		return fmt.Errorf("SendConfirmEmail: error updating user entry after email sent: %s", err)
+	}
+
+	return nil
+}