Improve tool detail formatting

internal/telegram/render.go

@@ -35,6 +35,119 @@ func ExpandableQuoteHTML(text string) string {
 	return "<blockquote expandable>" + EscapeHTML(text) + "</blockquote>"
 }
 
+func ExpandableQuoteRawHTML(htmlText string) string {
+	htmlText = strings.TrimSpace(htmlText)
+	if htmlText == "" {
+		return ""
+	}
+	return "<blockquote expandable>" + htmlText + "</blockquote>"
+}
+
+func SummaryDetailsRawHTML(summary, detailsHTML string) string {
+	summary = strings.TrimSpace(summary)
+	detailsHTML = strings.TrimSpace(detailsHTML)
+	if detailsHTML == "" {
+		return EscapeHTML(summary)
+	}
+	if summary == "" {
+		return ExpandableQuoteRawHTML(detailsHTML)
+	}
+	return EscapeHTML(summary) + "\n" + ExpandableQuoteRawHTML(detailsHTML)
+}
+
+func SummaryDetailsRawHTMLLimited(summary, detailsHTML string, limit int) string {
+	if limit <= 0 {
+		limit = TelegramHTMLMessageLimit
+	}
+	summary = strings.TrimSpace(summary)
+	detailsHTML = strings.TrimSpace(detailsHTML)
+	out := SummaryDetailsRawHTML(summary, detailsHTML)
+	if len([]rune(out)) <= limit || detailsHTML == "" {
+		return out
+	}
+
+	plain := stripSimpleHTML(detailsHTML)
+	suffix := "\n...[truncated]"
+	runes := []rune(plain)
+	for len(runes) > 0 {
+		candidateLen := len(runes) - max(1, (len([]rune(out))-limit)/2)
+		if candidateLen < 0 {
+			candidateLen = 0
+		}
+		if candidateLen > len(runes) {
+			candidateLen = len(runes)
+		}
+		candidate := CodeBlockHTML("text", strings.TrimSpace(string(runes[:candidateLen]))+suffix)
+		out = SummaryDetailsRawHTML(summary, candidate)
+		if len([]rune(out)) <= limit || candidateLen == 0 {
+			return out
+		}
+		runes = runes[:candidateLen]
+	}
+	return SummaryDetailsRawHTML(summary, EscapeHTML(suffix))
+}
+
+func CodeBlockHTML(language, text string) string {
+	text = strings.TrimSpace(text)
+	if text == "" {
+		return ""
+	}
+	language = safeCodeLanguage(language)
+	return "<pre><code class=\"language-" + language + "\">" + EscapeHTML(text) + "</code></pre>"
+}
+
+func FieldHTML(label, value string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return ""
+	}
+	return "<b>" + EscapeHTML(label) + ":</b> " + EscapeHTML(value)
+}
+
+func safeCodeLanguage(language string) string {
+	language = strings.ToLower(strings.TrimSpace(language))
+	if language == "" {
+		return "text"
+	}
+	var builder strings.Builder
+	for _, r := range language {
+		switch {
+		case r >= 'a' && r <= 'z':
+			builder.WriteRune(r)
+		case r >= '0' && r <= '9':
+			builder.WriteRune(r)
+		case r == '-', r == '_':
+			builder.WriteRune(r)
+		}
+	}
+	if builder.Len() == 0 {
+		return "text"
+	}
+	return builder.String()
+}
+
+func stripSimpleHTML(htmlText string) string {
+	replacer := strings.NewReplacer(
+		"<pre>", "", "</pre>", "",
+		"<code>", "", "</code>", "",
+		"<b>", "", "</b>", "",
+		"<i>", "", "</i>", "",
+	)
+	text := replacer.Replace(htmlText)
+	for {
+		start := strings.Index(text, "<code ")
+		if start < 0 {
+			break
+		}
+		end := strings.Index(text[start:], ">")
+		if end < 0 {
+			break
+		}
+		text = text[:start] + text[start+end+1:]
+	}
+	return html.UnescapeString(text)
+}
+
 func SummaryDetailsHTMLLimited(summary, details string, limit int) string {
 	if limit <= 0 {
 		limit = TelegramHTMLMessageLimit