initial

includes/Services/Emails/RsvEmailSender.php

@@ -0,0 +1,22 @@
+<?php
+
+class RsvEmailSender {
+
+    private function headers(): array {
+        return [
+            'From: ' . get_bloginfo('name') . ' <' . get_option('admin_email') . '>',
+            'Content-Type: text/html; charset=UTF-8',
+        ];
+    }
+
+    private function do_send(string $to, string $subject, string $body): void {
+        $success = wp_mail($to, $subject, $body, $this->headers());
+        if (!$success) {
+            throw new \RuntimeException('wp_mail failed for ' . $to);
+        }
+    }
+
+    public function send(string $to, string $subject, string $body): void {
+        $this->do_send($to, $subject, $body);
+    }
+}

includes/Services/Emails/RsvEmailTemplater.php

@@ -0,0 +1,9 @@
+<?php
+
+class RsvEmailTemplater {
+    public function render(string $template, array $data) : string {
+        return preg_replace_callback('/{{\s*(\w+)\s*}}/', function($matches) use ($data) {
+            return $data[$matches[1]] ?? '';
+        }, $template);
+    }
+}