Initial commit

internal/mailer/doc.go

@@ -0,0 +1,3 @@
+// Package mailer renders and delivers Gardomatic transactional email through
+// SMTP or an append-only development file.
+package mailer

internal/mailer/mailer.go

@@ -0,0 +1,163 @@
+package mailer
+
+import (
+	"bytes"
+	"embed"
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/wneessen/go-mail"
+
+	ht "html/template"
+	tt "text/template"
+)
+
+//go:embed "templates"
+var templateFS embed.FS
+
+// Mailer renders embedded templates and delivers the resulting message.
+type Mailer struct {
+	client   *mail.Client
+	mode     Mode
+	filePath string
+	sender   string
+	fileMu   sync.Mutex
+}
+
+// Mode selects the delivery backend used by a Mailer.
+type Mode string
+
+const (
+	// ModeSMTP sends messages through an SMTP server.
+	ModeSMTP Mode = "smtp"
+	// ModeFile appends rendered messages to a local development file.
+	ModeFile Mode = "file"
+)
+
+// Config contains SMTP or development-file delivery settings.
+type Config struct {
+	Mode     Mode
+	Host     string
+	Port     int
+	Username string
+	Password string
+	Sender   string
+	FilePath string
+}
+
+// New validates config and creates a Mailer.
+func New(config Config) (*Mailer, error) {
+	mailer := &Mailer{
+		mode:     config.Mode,
+		filePath: config.FilePath,
+		sender:   config.Sender,
+	}
+
+	switch config.Mode {
+	case ModeSMTP:
+		client, err := mail.NewClient(
+			config.Host,
+			mail.WithSMTPAuth(mail.SMTPAuthLogin),
+			mail.WithPort(config.Port),
+			mail.WithUsername(config.Username),
+			mail.WithPassword(config.Password),
+			mail.WithTimeout(5*time.Second),
+		)
+		if err != nil {
+			return nil, err
+		}
+		mailer.client = client
+	case ModeFile:
+		if config.FilePath == "" {
+			return nil, errors.New("mailer: file path must not be empty in file mode")
+		}
+	default:
+		return nil, fmt.Errorf("mailer: unsupported mode %q", config.Mode)
+	}
+
+	return mailer, nil
+}
+
+// Send renders templateFile with data and delivers it to recipient.
+func (m *Mailer) Send(recipient string, templateFile string, data any) error {
+	textTmpl, err := tt.New("").ParseFS(templateFS, "templates/"+templateFile)
+	if err != nil {
+		return err
+	}
+
+	subject := new(bytes.Buffer)
+	err = textTmpl.ExecuteTemplate(subject, "subject", data)
+	if err != nil {
+		return err
+	}
+
+	plainBody := new(bytes.Buffer)
+	err = textTmpl.ExecuteTemplate(plainBody, "plainBody", data)
+	if err != nil {
+		return err
+	}
+
+	htmlTmpl, err := ht.New("").ParseFS(templateFS, "templates/"+templateFile)
+	if err != nil {
+		return err
+	}
+
+	htmlBody := new(bytes.Buffer)
+	err = htmlTmpl.ExecuteTemplate(htmlBody, "htmlBody", data)
+	if err != nil {
+		return err
+	}
+
+	msg := mail.NewMsg()
+
+	err = msg.To(recipient)
+	if err != nil {
+		return err
+	}
+
+	err = msg.From(m.sender)
+	if err != nil {
+		return err
+	}
+
+	msg.Subject(subject.String())
+	msg.SetBodyString(mail.TypeTextPlain, plainBody.String())
+	msg.AddAlternativeString(mail.TypeTextHTML, htmlBody.String())
+
+	if m.mode == ModeFile {
+		return m.appendToFile(msg)
+	}
+
+	return m.client.DialAndSend(msg)
+}
+
+func (m *Mailer) appendToFile(msg *mail.Msg) error {
+	var content bytes.Buffer
+	if _, err := msg.WriteTo(&content); err != nil {
+		return fmt.Errorf("mailer: format message: %w", err)
+	}
+
+	m.fileMu.Lock()
+	defer m.fileMu.Unlock()
+
+	file, err := os.OpenFile(m.filePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o600)
+	if err != nil {
+		return fmt.Errorf("mailer: open output file: %w", err)
+	}
+	defer file.Close()
+
+	if _, err = file.WriteString("\n=== gardomatic mail ===\n"); err != nil {
+		return fmt.Errorf("mailer: append separator: %w", err)
+	}
+	if _, err = content.WriteTo(file); err != nil {
+		return fmt.Errorf("mailer: append message: %w", err)
+	}
+	if _, err = file.WriteString("\n"); err != nil {
+		return fmt.Errorf("mailer: finish message: %w", err)
+	}
+
+	return nil
+}

internal/mailer/mailer_test.go

@@ -0,0 +1,64 @@
+package mailer
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestFileModeAppendsMessages(t *testing.T) {
+	filePath := filepath.Join(t.TempDir(), "mails.log")
+	m, err := New(Config{
+		Mode:     ModeFile,
+		Sender:   "gardomatic@example.com",
+		FilePath: filePath,
+	})
+	if err != nil {
+		t.Fatalf("New() returned an error: %v", err)
+	}
+
+	data := map[string]any{
+		"userID":          42,
+		"activationToken": "test-token",
+	}
+	for _, recipient := range []string{"alice@example.com", "bob@example.com"} {
+		if err = m.Send(recipient, "user_welcome.tmpl", data); err != nil {
+			t.Fatalf("Send() returned an error: %v", err)
+		}
+	}
+
+	content, err := os.ReadFile(filePath)
+	if err != nil {
+		t.Fatalf("reading mail output: %v", err)
+	}
+	output := string(content)
+
+	if got := strings.Count(output, "=== gardomatic mail ==="); got != 2 {
+		t.Errorf("message count = %d, want 2", got)
+	}
+	for _, expected := range []string{
+		"alice@example.com",
+		"bob@example.com",
+		"Subject: Welcome to Gardomatic!",
+		"test-token",
+	} {
+		if !strings.Contains(output, expected) {
+			t.Errorf("output does not contain %q", expected)
+		}
+	}
+}
+
+func TestFileModeRequiresPath(t *testing.T) {
+	_, err := New(Config{Mode: ModeFile, Sender: "gardomatic@example.com"})
+	if err == nil {
+		t.Fatal("New() returned no error without a file path")
+	}
+}
+
+func TestNewRejectsUnknownMode(t *testing.T) {
+	_, err := New(Config{Mode: "unknown", Sender: "gardomatic@example.com"})
+	if err == nil {
+		t.Fatal("New() returned no error for an unknown mode")
+	}
+}

internal/mailer/templates/email_change.tmpl

@@ -0,0 +1,3 @@
+{{define "subject"}}E-Mail-Adresse bei Gardomatic bestätigen{{end}}
+{{define "plainBody"}}Bestätige deine neue E-Mail-Adresse: {{.confirmationURL}}{{end}}
+{{define "htmlBody"}}<p>Bestätige deine neue E-Mail-Adresse:</p><p><a href="{{.confirmationURL}}">E-Mail-Adresse bestätigen</a></p>{{end}}

internal/mailer/templates/garden_invite.tmpl

@@ -0,0 +1,3 @@
+{{define "subject"}}Einladung zu Gardomatic{{end}}
+{{define "plainBody"}}Du wurdest zu einem Garten eingeladen. Einladung annehmen: {{.inviteURL}}{{end}}
+{{define "htmlBody"}}<p>Du wurdest zu einem Garten eingeladen.</p><p><a href="{{.inviteURL}}">Einladung annehmen</a></p>{{end}}

internal/mailer/templates/test_mail.tmpl

@@ -0,0 +1,25 @@
+{{define "subject"}}Gardomatic Testmail{{end}}
+
+{{define "plainBody"}}
+Hallo,
+
+diese Testmail bestätigt, dass der Mailversand von Gardomatic funktioniert.
+
+Viele Grüße
+Gardomatic
+{{end}}
+
+{{define "htmlBody"}}
+<!doctype html>
+<html lang="de">
+<head>
+    <meta name="viewport" content="width=device-width">
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+</head>
+<body>
+    <p>Hallo,</p>
+    <p>diese Testmail bestätigt, dass der Mailversand von Gardomatic funktioniert.</p>
+    <p>Viele Grüße<br>Gardomatic</p>
+</body>
+</html>
+{{end}}

internal/mailer/templates/token_activation.tmpl

@@ -0,0 +1,48 @@
+{{define "subject"}}Activate your Gardomatic account{{end}}
+
+{{define "plainBody"}}
+Hi,
+
+{{if .activationURL}}Activate your account using this link:
+
+{{.activationURL}}
+
+Alternatively, enter this activation token on the activation page:
+{{.activationToken}}
+{{else}}Please send a `PUT /v1/users/activated` request with the following JSON body to activate your account:
+
+{"token": "{{.activationToken}}"}
+{{end}}
+
+Please note that this is a one-time use token and it will expire in 3 days.
+
+Thanks,
+
+The Gardomatic Team
+{{end}}
+
+{{define "htmlBody"}}
+<!doctype html>
+<html>
+  <head>
+    <meta name="viewport" content="width=device-width" />
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+  </head>
+  <body>
+    <p>Hi,</p>
+    {{if .activationURL}}
+    <p><a href="{{.activationURL}}">Activate your Gardomatic account</a></p>
+    <p>Alternatively, enter this activation token on the activation page:</p>
+    <pre><code>{{.activationToken}}</code></pre>
+    {{else}}
+    <p>Please send a <code>PUT /v1/users/activated</code> request with the following JSON body to activate your account:</p>
+    <pre><code>
+    {"token": "{{.activationToken}}"}
+    </code></pre> 
+    {{end}}
+    <p>Please note that this is a one-time use token and it will expire in 3 days.</p>
+    <p>Thanks,</p>
+    <p>The Gardomatic Team</p>
+  </body>
+</html>
+{{end}}

internal/mailer/templates/token_password_reset.tmpl

@@ -0,0 +1,37 @@
+{{define "subject"}}Reset your Gardomatic password{{end}}
+
+{{define "plainBody"}}
+Hi,
+
+Please send a `PUT /v1/users/password` request with the following JSON body to set a new password:
+
+{"password": "your new password", "token": "{{.passwordResetToken}}"}
+
+Please note that this is a one-time use token and it will expire in 45 minutes. If you need 
+another token please make a `POST /v1/tokens/password-reset` request.
+
+Thanks,
+
+The Gardomatic Team
+{{end}}
+
+{{define "htmlBody"}}
+<!doctype html>
+<html>
+  <head>
+    <meta name="viewport" content="width=device-width" />
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+  </head>
+  <body>
+    <p>Hi,</p>
+    <p>Please send a <code>PUT /v1/users/password</code> request with the following JSON body to set a new password:</p>
+    <pre><code>
+    {"password": "your new password", "token": "{{.passwordResetToken}}"}
+    </code></pre>  
+    <p>Please note that this is a one-time use token and it will expire in 45 minutes.
+    If you need another token please make a <code>POST /v1/tokens/password-reset</code> request.</p>
+    <p>Thanks,</p>
+    <p>The Gardomatic Team</p>
+  </body>
+</html>
+{{end}}

internal/mailer/templates/user_invitation.tmpl

@@ -0,0 +1,31 @@
+{{define "subject"}}Einladung zu Gardomatic{{end}}
+
+{{define "plainBody"}}
+Hallo {{.name}},
+
+du wurdest zu Gardomatic eingeladen. Öffne den folgenden Link, um deinen Account zu aktivieren und ein Passwort festzulegen:
+
+{{.activationURL}}
+
+Der Link ist drei Tage lang gültig.
+
+Viele Grüße
+Gardomatic
+{{end}}
+
+{{define "htmlBody"}}
+<!doctype html>
+<html lang="de">
+<head>
+    <meta name="viewport" content="width=device-width">
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+</head>
+<body>
+    <p>Hallo {{.name}},</p>
+    <p>du wurdest zu Gardomatic eingeladen.</p>
+    <p><a href="{{.activationURL}}">Account aktivieren und Passwort festlegen</a></p>
+    <p>Der Link ist drei Tage lang gültig.</p>
+    <p>Viele Grüße<br>Gardomatic</p>
+</body>
+</html>
+{{end}}

internal/mailer/templates/user_welcome.tmpl

@@ -0,0 +1,59 @@
+{{define "subject"}}Welcome to Gardomatic!{{end}}
+
+{{define "plainBody"}}
+Hi,
+
+Thanks for signing up for a Gardomatic account. We're excited to have you on board!
+
+For future reference, your user ID number is {{.userID}}.
+
+{{if .activationURL}}Activate your account using this link:
+
+{{.activationURL}}
+
+Alternatively, enter this activation token on the activation page:
+{{.activationToken}}
+{{else}}Please send a request to the `PUT /v1/users/activated` endpoint with the following JSON
+body to activate your account:
+
+{"token": "{{.activationToken}}"}
+{{end}}
+
+Please note that this is a one-time use token and it will expire in 3 days.
+
+Thanks,
+
+The Gardomatic Team
+{{end}}
+
+{{define "htmlBody"}}
+<!doctype html>
+<html>
+
+<head>
+    <meta name="viewport" content="width=device-width" />
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+</head>
+
+<body>
+    <p>Hi,</p>
+    <p>Thanks for signing up for a Gardomatic account. We're excited to have you on board!</p>
+    <p>For future reference, your user ID number is {{.userID}}.</p>
+    {{if .activationURL}}
+    <p><a href="{{.activationURL}}">Activate your Gardomatic account</a></p>
+    <p>Alternatively, enter this activation token on the activation page:</p>
+    <pre><code>{{.activationToken}}</code></pre>
+    {{else}}
+    <p>Please send a request to the <code>PUT /v1/users/activated</code> endpoint with the
+    following JSON body to activate your account:</p>
+    <pre><code>
+    {"token": "{{.activationToken}}"}
+    </code></pre>
+    {{end}}
+    <p>Please note that this is a one-time use token and it will expire in 3 days.</p>
+    <p>Thanks,</p>
+    <p>The Gardomatic Team</p>
+</body>
+
+</html>
+{{end}}