feedback formatter

2026-10-09 06:40:13 +05:30
parent 6633d0cca3
commit 7d7ba2a002
4 changed files with 219 additions and 8 deletions
@@ -11,6 +11,7 @@ import (
 	"github.com/prabhupadasays/spsays-bff/internal/model"
 	"github.com/prabhupadasays/spsays-bff/internal/repository"
 	"github.com/prabhupadasays/spsays-bff/pkg/mailer"
+	"github.com/prabhupadasays/spsays-bff/pkg/richtext"
 	"go.uber.org/zap"
 )

@@ -335,8 +336,9 @@ func (s *AdminService) ReplyFeedback(ctx context.Context, id, message string) (f
 	var buf bytes.Buffer
 	if err := feedbackReplyEmailTpl.Execute(&buf, map[string]any{
 		"RecipientName": name,
-		"Reply":         message,
-		"URL":           s.frontendURL,
+		// Rendered markers; escaped by richtext, newlines become <br>.
+		"Reply": richtext.ToHTML(message),
+		"URL":   s.frontendURL,
 	}); err != nil {
 		s.logger.Warn("render feedback reply email failed", zap.Error(err))
 		return true, false, nil
@@ -435,7 +437,7 @@ var feedbackReplyEmailTpl = template.Must(template.New("feedbackReply").Parse(`<

  <p>Thank you for writing to us. Here's our reply to your feedback:</p>

-  <blockquote style="white-space:pre-line;border-left:3px solid #9a6b2f;padding-left:1em;margin:1em 0;color:#3a3024">{{.Reply}}</blockquote>
+  <blockquote style="border-left:3px solid #9a6b2f;padding-left:1em;margin:1em 0;color:#3a3024">{{.Reply}}</blockquote>

  <p style="margin:1.25em 0">
    <a href="{{.URL}}" style="display:inline-block;background:#9a6b2f;color:#fff;text-decoration:none;padding:0.6em 1.3em;border-radius:8px;font-weight:600">Open Prabhupāda Says</a>
@@ -26,6 +26,7 @@ import (
 	"github.com/prabhupadasays/spsays-bff/internal/repository"
 	"github.com/prabhupadasays/spsays-bff/pkg/mailer"
 	"github.com/prabhupadasays/spsays-bff/pkg/realtime"
+	"github.com/prabhupadasays/spsays-bff/pkg/richtext"
 	"go.uber.org/zap"
 )

@@ -300,7 +301,7 @@ func (s *NotificationService) NotifyPostLike(ctx context.Context, postID, author
 	if s.push != nil && !prefOff(off, NotifPostLike, repository.ChannelPush) {
 		s.push.SendToUser(ctx, authorID, PushPayload{
 			Title: "New Like",
-			Body:  body,
+			Body:  richtext.Plain(body),
 			URL:   url,
 			Icon:  s.iconURL(),
 			Tag:   NotifPostLike + ":" + postID,
@@ -642,7 +643,7 @@ func (s *NotificationService) NotifyAdminMessage(ctx context.Context, recipientI
 	if s.rt != nil {
 		if err := s.rt.TriggerUser(ctx, recipientID, "notification", map[string]any{
 			"kind": "admin_message",
-			"body": body,
+			"body": richtext.Plain(body),
 		}); err != nil {
 			s.logger.Warn("realtime admin message publish failed",
 				zap.String("recipient", recipientID), zap.Error(err))
@@ -670,8 +671,10 @@ func (s *NotificationService) NotifyAdminMessage(ctx context.Context, recipientI
 		if err := adminMessageEmailTpl.Execute(&buf, map[string]any{
 			"RecipientName": recipient.Name,
 			"Title":         strings.TrimSpace(title),
-			"Body":          body,
-			"URL":           url,
+			// Rendered markers (bold, links…). Already escaped by richtext,
+			// and its <br>s replace the old white-space:pre-line.
+			"Body": richtext.ToHTML(body),
+			"URL":  url,
 		}); err != nil {
 			s.logger.Warn("render admin message email failed", zap.Error(err))
 		} else {
@@ -882,7 +885,7 @@ var adminMessageEmailTpl = template.Must(template.New("adminMessage").Parse(`<di

  {{if .Title}}<p style="font-weight:600;font-size:19px;margin-bottom:0.5em">{{.Title}}</p>{{end}}

-  <p style="white-space:pre-line">{{.Body}}</p>
+  <p>{{.Body}}</p>

  <p style="margin:1.25em 0">
    <a href="{{.URL}}" style="display:inline-block;background:#9a6b2f;color:#fff;text-decoration:none;padding:0.6em 1.3em;border-radius:8px;font-weight:600">Open Prabhupāda Says</a>
@@ -0,0 +1,121 @@
+// Package richtext renders the light formatting the admin panel's message
+// fields allow, for the two places that text leaves the app:
+//
+//   - ToHTML, for email bodies.
+//   - Plain, for push notifications and toasts, which can't render markup.
+//
+// The format is a handful of markers typed into a plain textarea:
+//
+//	*bold*   _italic_   __underline__   ~strike~   [label](https://…)
+//
+// plus bare http(s) URLs, which become links on their own. *bold* and ~strike~
+// match what chat already uses, so the two read the same.
+//
+// Safety comes from the order of operations: the input is HTML-escaped FIRST,
+// and only then are the markers turned into tags. Nothing an author types can
+// therefore produce markup of its own — the only tags in the output are the
+// ones this package writes. Links are limited to http and https, so a
+// `javascript:` URL is never made clickable.
+package richtext
+
+import (
+	"fmt"
+	"html"
+	"html/template"
+	"regexp"
+	"strings"
+)
+
+var (
+	// A labelled link, or a bare URL. One alternation so a URL is never
+	// linked twice — once as the label's target and once on its own.
+	linkRe = regexp.MustCompile(`\[([^\]\n]+)\]\((https?://[^\s)]+)\)|(https?://[^\s<]+)`)
+
+	underlineRe = regexp.MustCompile(`__([^_\n]+?)__`)
+	boldRe      = regexp.MustCompile(`\*([^*\n]+?)\*`)
+	strikeRe    = regexp.MustCompile(`~([^~\n]+?)~`)
+	// Italic needs a non-word character (or an edge) on each side, so the
+	// underscores inside snake_case or a handle aren't read as markers. RE2
+	// has no lookbehind, so the neighbours are captured and put back.
+	italicRe = regexp.MustCompile(`(^|[^\w])_([^_\n]+?)_($|[^\w])`)
+
+	// Punctuation that ends a sentence rather than belonging to the URL.
+	trailingPunct = ".,;:!?)"
+)
+
+// placeholder marks where a finished link sits while markers are applied, so
+// the underscores and tildes common in URLs aren't read as formatting.
+func placeholder(i int) string { return fmt.Sprintf("\x00%d\x00", i) }
+
+// splitTrailing separates sentence punctuation from the end of a bare URL.
+func splitTrailing(u string) (url, tail string) {
+	end := len(u)
+	for end > 0 && strings.ContainsRune(trailingPunct, rune(u[end-1])) {
+		end--
+	}
+	return u[:end], u[end:]
+}
+
+// ToHTML renders the markers as HTML for an email body.
+func ToHTML(s string) template.HTML {
+	escaped := html.EscapeString(strings.ReplaceAll(s, "\r\n", "\n"))
+
+	var links []string
+	withHolders := linkRe.ReplaceAllStringFunc(escaped, func(m string) string {
+		parts := linkRe.FindStringSubmatch(m)
+		var label, href, tail string
+		if parts[1] != "" {
+			label, href = parts[1], parts[2]
+		} else {
+			href, tail = splitTrailing(parts[3])
+			label = href
+		}
+		// href is already escaped (it came from the escaped input), so it is
+		// safe inside the attribute as-is.
+		links = append(links, fmt.Sprintf(
+			`<a href="%s" style="color:#9a6b2f;font-weight:600">%s</a>`, href, label))
+		return placeholder(len(links)-1) + tail
+	})
+
+	out := underlineRe.ReplaceAllString(withHolders, `<u>$1</u>`)
+	out = boldRe.ReplaceAllString(out, `<strong>$1</strong>`)
+	out = strikeRe.ReplaceAllString(out, `<s>$1</s>`)
+	out = italicRe.ReplaceAllString(out, `$1<em>$2</em>$3`)
+
+	for i, l := range links {
+		out = strings.Replace(out, placeholder(i), l, 1)
+	}
+	out = strings.ReplaceAll(out, "\n", "<br>")
+
+	// Every tag here was written by this function, and all author text was
+	// escaped before any of them were added.
+	return template.HTML(out) //nolint:gosec // see above
+}
+
+// Plain strips the markers for surfaces that can't render them — a push
+// notification or a toast. A labelled link keeps only its label; a bare URL
+// stays as written, since it is still useful to see.
+func Plain(s string) string {
+	s = strings.ReplaceAll(s, "\r\n", "\n")
+
+	var links []string
+	withHolders := linkRe.ReplaceAllStringFunc(s, func(m string) string {
+		parts := linkRe.FindStringSubmatch(m)
+		if parts[1] != "" {
+			links = append(links, parts[1])
+		} else {
+			links = append(links, parts[3])
+		}
+		return placeholder(len(links) - 1)
+	})
+
+	out := underlineRe.ReplaceAllString(withHolders, `$1`)
+	out = boldRe.ReplaceAllString(out, `$1`)
+	out = strikeRe.ReplaceAllString(out, `$1`)
+	out = italicRe.ReplaceAllString(out, `$1$2$3`)
+
+	for i, l := range links {
+		out = strings.Replace(out, placeholder(i), l, 1)
+	}
+	return out
+}
@@ -0,0 +1,85 @@
+package richtext
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestToHTML_Markers(t *testing.T) {
+	cases := []struct{ in, want string }{
+		{"*bold*", "<strong>bold</strong>"},
+		{"_italic_", "<em>italic</em>"},
+		{"__under__", "<u>under</u>"},
+		{"~gone~", "<s>gone</s>"},
+		{"a *b* and _c_", "a <strong>b</strong> and <em>c</em>"},
+		{"line one\nline two", "line one<br>line two"},
+		// Underscores inside words are not italics.
+		{"snake_case_name", "snake_case_name"},
+		{"@some_handle here", "@some_handle here"},
+	}
+	for _, c := range cases {
+		if got := string(ToHTML(c.in)); got != c.want {
+			t.Errorf("ToHTML(%q) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}
+
+func TestToHTML_Links(t *testing.T) {
+	got := string(ToHTML("see [the gītā](https://prabhupadasays.org/books/bg)"))
+	if !strings.Contains(got, `href="https://prabhupadasays.org/books/bg"`) ||
+		!strings.Contains(got, ">the gītā</a>") {
+		t.Errorf("labelled link: %q", got)
+	}
+
+	// A bare URL becomes a link, but sentence punctuation stays outside it.
+	got = string(ToHTML("Visit https://prabhupadasays.org."))
+	if !strings.Contains(got, `href="https://prabhupadasays.org"`) ||
+		!strings.HasSuffix(got, "</a>.") {
+		t.Errorf("bare link with trailing period: %q", got)
+	}
+
+	// Underscores and tildes inside a URL are not formatting.
+	got = string(ToHTML("https://example.com/a_b_c~d"))
+	if strings.Contains(got, "<em>") || strings.Contains(got, "<s>") {
+		t.Errorf("markers applied inside a URL: %q", got)
+	}
+}
+
+// The security property: nothing typed can become markup of its own.
+func TestToHTML_EscapesAuthorInput(t *testing.T) {
+	cases := []string{
+		`<script>alert(1)</script>`,
+		`<img src=x onerror=alert(1)>`,
+		`*<b>bold</b>*`,
+		`[click](javascript:alert(1))`,
+		`[x](https://ok.example/" onmouseover="alert(1))`,
+	}
+	for _, in := range cases {
+		got := string(ToHTML(in))
+		if strings.Contains(got, "<script") || strings.Contains(got, "<img") ||
+			strings.Contains(got, "<b>") || strings.Contains(got, "javascript:alert") && strings.Contains(got, "href=\"javascript") {
+			t.Errorf("ToHTML(%q) produced author markup: %q", in, got)
+		}
+		if strings.Contains(got, `" onmouseover=`) {
+			t.Errorf("ToHTML(%q) let a quote break out of an attribute: %q", in, got)
+		}
+	}
+	// A javascript: URL is never made a link at all.
+	if got := string(ToHTML(`[click](javascript:alert(1))`)); strings.Contains(got, "<a ") {
+		t.Errorf("javascript: URL was linked: %q", got)
+	}
+}
+
+func TestPlain(t *testing.T) {
+	cases := []struct{ in, want string }{
+		{"*New:* _chat_ is __here__ ~soon~", "New: chat is here soon"},
+		{"read [the gītā](https://x.example)", "read the gītā"},
+		{"see https://prabhupadasays.org", "see https://prabhupadasays.org"},
+		{"snake_case stays", "snake_case stays"},
+	}
+	for _, c := range cases {
+		if got := Plain(c.in); got != c.want {
+			t.Errorf("Plain(%q) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}