Files
plumber/internal/mail/mail.go
codegirl007 f0591ccea3 Generalize post reply notifications (#6)
## Summary
- Notify the direct parent post author for replies throughout nested conversations
- Skip root creation, self-replies, edits, disabled mail, and recipients without email
- Link directly to each reply and use per-reply Resend idempotency

Co-authored-by: codegirl-007 <s.raide@gmail.com>
2026-08-27 16:03:33 +00:00

206 lines
7.5 KiB
Go

package mail
import (
"context"
_ "embed"
"fmt"
"html"
"net/url"
"os"
"strings"
"github.com/resend/resend-go/v3"
)
//go:embed mark.png
var markPNG []byte
// PostReply is the payload for notifying a post author of a direct reply.
type PostReply struct {
ToEmail string
ToName string
RootID string
RootTitle string
ReplyID string
ReplyBody string
ReplyAuthorName string
}
// Notifier sends transactional email about post replies.
type Notifier interface {
NotifyPostReply(ctx context.Context, msg PostReply) error
}
// Nop is a no-op Notifier used when Resend is not configured.
type Nop struct{}
func (Nop) NotifyPostReply(context.Context, PostReply) error { return nil }
// Resend sends via the Resend HTTP API.
type Resend struct {
client *resend.Client
from string
baseURL string
}
// FromEnv builds a Notifier from RESEND_* and APP_BASE_URL.
// Returns Nop when RESEND_API_KEY is unset.
func FromEnv() (Notifier, error) {
key := strings.TrimSpace(os.Getenv("RESEND_API_KEY"))
if key == "" {
return Nop{}, nil
}
from := strings.TrimSpace(os.Getenv("RESEND_FROM"))
base := strings.TrimRight(strings.TrimSpace(os.Getenv("APP_BASE_URL")), "/")
if from == "" {
return nil, fmt.Errorf("RESEND_FROM is required when RESEND_API_KEY is set")
}
if base == "" {
return nil, fmt.Errorf("APP_BASE_URL is required when RESEND_API_KEY is set")
}
return &Resend{
client: resend.NewClient(key),
from: from,
baseURL: base,
}, nil
}
func (r *Resend) NotifyPostReply(ctx context.Context, msg PostReply) error {
if r == nil || r.client == nil {
return nil
}
to := strings.TrimSpace(msg.ToEmail)
if to == "" {
return nil
}
text, htmlBody := postReplyContent(r.baseURL, msg)
params := &resend.SendEmailRequest{
From: r.from,
To: []string{to},
Subject: "New reply to your post",
Text: text,
Html: htmlBody,
Attachments: []*resend.Attachment{{
Content: markPNG,
Filename: "ask-a-plumber-first.png",
ContentType: "image/png",
ContentId: "reply-notification-mark",
}},
}
opts := &resend.SendEmailOptions{
IdempotencyKey: "post-reply:" + msg.ReplyID,
}
_, err := r.client.Emails.SendWithOptions(ctx, params, opts)
return err
}
func postReplyContent(baseURL string, msg PostReply) (string, string) {
link := strings.TrimRight(baseURL, "/") +
"/questions/" + url.PathEscape(msg.RootID) +
"#post-" + url.PathEscape(msg.ReplyID)
title := replyRootTitle(msg.RootTitle)
author := strings.TrimSpace(msg.ReplyAuthorName)
if author == "" {
author = "Someone"
}
text := fmt.Sprintf(
"Hi%s,\n\n%s replied in %q:\n\n%s\n\nView the reply:\n%s\n",
greetingName(msg.ToName),
author,
title,
msg.ReplyBody,
link,
)
htmlBody := strings.NewReplacer(
"{{PREHEADER}}", html.EscapeString(author+" replied in "+title+"."),
"{{GREETING}}", html.EscapeString(greetingName(msg.ToName)),
"{{TITLE}}", html.EscapeString(title),
"{{AUTHOR}}", html.EscapeString(author),
"{{REPLY}}", html.EscapeString(msg.ReplyBody),
"{{LINK}}", html.EscapeString(link),
"{{MARK}}", "cid:reply-notification-mark",
).Replace(postReplyHTML)
return text, htmlBody
}
func replyRootTitle(title string) string {
title = strings.TrimSpace(title)
if title == "" {
return "your conversation"
}
return title
}
const postReplyHTML = `<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="color-scheme" content="dark">
<meta name="supported-color-schemes" content="dark">
<title>New reply to your conversation</title>
</head>
<body style="margin:0;padding:0;background:#161719;color:#ecebe7;font-family:Arial,'Helvetica Neue',sans-serif;">
<div style="display:none;max-height:0;overflow:hidden;opacity:0;color:transparent;">{{PREHEADER}}</div>
<table role="presentation" width="100%" cellspacing="0" cellpadding="0" border="0" style="width:100%;background:#161719;">
<tr>
<td align="center" style="padding:32px 16px;">
<table role="presentation" width="560" cellspacing="0" cellpadding="0" border="0" style="width:100%;max-width:560px;background:#1e2023;border:1px solid #2e3136;border-top:3px solid #e96a26;border-radius:3px;">
<tr>
<td style="padding:24px 28px 20px;border-bottom:1px solid #2e3136;">
<table role="presentation" cellspacing="0" cellpadding="0" border="0">
<tr>
<td style="padding-right:12px;vertical-align:middle;">
<img src="{{MARK}}" width="32" height="32" alt="" style="display:block;width:32px;height:32px;border:0;">
</td>
<td style="vertical-align:middle;">
<div style="color:#ecebe7;font-size:14px;font-weight:700;line-height:1.2;letter-spacing:1px;text-transform:uppercase;">Ask a Plumber First</div>
<div style="margin-top:4px;color:#8d9096;font-family:'Courier New',monospace;font-size:10px;line-height:1.2;letter-spacing:1.4px;text-transform:uppercase;">Bay Area · Shop Dispatch</div>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td style="padding:30px 28px 32px;">
<div style="margin:0 0 10px;color:#e96a26;font-family:'Courier New',monospace;font-size:11px;font-weight:700;line-height:1.4;letter-spacing:1.8px;text-transform:uppercase;">New reply</div>
<h1 style="margin:0;color:#ecebe7;font-size:28px;font-weight:600;line-height:1.2;letter-spacing:-0.4px;">The conversation has a new reply.</h1>
<p style="margin:18px 0 0;color:#b8babf;font-size:16px;line-height:1.6;">Hi{{GREETING}}, {{AUTHOR}} replied in:</p>
<p style="margin:8px 0 0;color:#ecebe7;font-size:17px;font-weight:600;line-height:1.45;">“{{TITLE}}”</p>
<table role="presentation" width="100%" cellspacing="0" cellpadding="0" border="0" style="width:100%;margin-top:24px;background:#161719;border:1px solid #2e3136;border-radius:3px;">
<tr>
<td style="padding:20px 18px;">
<div style="margin:0 0 10px;color:#8d9096;font-family:'Courier New',monospace;font-size:10px;font-weight:700;line-height:1.4;letter-spacing:1.5px;text-transform:uppercase;">The reply</div>
<div style="margin:0;color:#ecebe7;font-size:16px;line-height:1.65;white-space:pre-wrap;">{{REPLY}}</div>
</td>
</tr>
</table>
<table role="presentation" cellspacing="0" cellpadding="0" border="0" style="margin-top:26px;">
<tr>
<td bgcolor="#e96a26" style="border-radius:3px;">
<a href="{{LINK}}" style="display:inline-block;padding:13px 18px;color:#161719;font-family:'Courier New',monospace;font-size:12px;font-weight:700;line-height:1;text-decoration:none;letter-spacing:0.8px;text-transform:uppercase;">View the reply&nbsp;&rarr;</a>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td style="padding:18px 28px;border-top:1px solid #2e3136;color:#8d9096;font-family:'Courier New',monospace;font-size:10px;line-height:1.6;letter-spacing:0.4px;">
You received this because someone replied to your post on Ask a Plumber First.
</td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>`
func greetingName(name string) string {
name = strings.TrimSpace(name)
if name == "" {
return ""
}
return " " + name
}