refactor: decompose backend services and routes for maintainability

backend/src/services/planner-service.ts

@@ -0,0 +1,57 @@
+import { getPlannerUnitKind, isAmountBasedPackageType } from "../utils/package-profiles.js";
+
+// Escape HTML to prevent XSS in email templates.
+export function escapeHtml(text: string): string {
+	const htmlEscapes: Record<string, string> = {
+		"&": "&amp;",
+		"<": "&lt;",
+		">": "&gt;",
+		'"': "&quot;",
+		"'": "&#39;",
+	};
+	return text.replace(/[&<>"']/g, (char) => htmlEscapes[char] || char);
+}
+
+type MailDeliveryInfo = {
+	accepted?: unknown;
+	rejected?: unknown;
+	response?: unknown;
+};
+
+function normalizeRecipients(value: unknown): string[] {
+	if (!Array.isArray(value)) return [];
+	return value
+		.map((entry) => (typeof entry === "string" ? entry : String(entry ?? "")))
+		.map((entry) => entry.trim())
+		.filter(Boolean);
+}
+
+export function getDeliveryError(info: MailDeliveryInfo): string | null {
+	const accepted = normalizeRecipients(info.accepted);
+	const rejected = normalizeRecipients(info.rejected);
+
+	if (accepted.length > 0) return null;
+	if (rejected.length > 0) {
+		return `SMTP rejected all recipients: ${rejected.join(", ")}`;
+	}
+
+	if (typeof info.response === "string" && info.response.trim()) {
+		return `SMTP did not confirm accepted recipients. Response: ${info.response}`;
+	}
+
+	return "SMTP did not confirm accepted recipients.";
+}
+
+export function isContainerPackage(packageType?: string): boolean {
+	return isAmountBasedPackageType(packageType);
+}
+
+export function getPlannerUnit(
+	packageType: string | undefined,
+	tr: { common: { units: string; ml: string; pills: string } }
+): string {
+	const unitKind = getPlannerUnitKind(packageType);
+	if (unitKind === "units") return tr.common.units;
+	if (unitKind === "ml") return tr.common.ml;
+	return tr.common.pills;
+}