added base examples and drills

kata/notifications/original/notificationService.js

@@ -0,0 +1,33 @@
+const fs = require("fs");
+
+function sendReminder(filePath, userId, channel) {
+  const raw = fs.readFileSync(filePath, "utf8");
+  const state = JSON.parse(raw);
+  const user = state.users.find((item) => item.id === userId);
+
+  if (!user) {
+    throw new Error("User not found");
+  }
+
+  if (!user.remindersEnabled) {
+    return { sent: false, reason: "disabled" };
+  }
+
+  const hour = new Date().getHours();
+
+  if (hour < 8 || hour > 20) {
+    return { sent: false, reason: "quiet-hours" };
+  }
+
+  if (channel === "sms" && !user.phoneNumber) {
+    return { sent: false, reason: "missing-phone" };
+  }
+
+  user.lastReminderAt = new Date().toISOString();
+  fs.writeFileSync(filePath, JSON.stringify(state, null, 2));
+  console.log("Sent reminder", userId, channel);
+
+  return { sent: true, channel };
+}
+
+module.exports = { sendReminder };