// Test script: Exam events through Kafka → push-gateway → WebSocket (v2)
// Verifies that the 3 exam events (ExamExtended, ExamForceSubmitted,
// ExamQuestionReordered) traverse the new edu.notify.notification.sent topic
// and reach the WebSocket client with correct event_type passthrough.
//
// Usage: node services/push-gateway/scripts/test-exam-events.mjs

import WebSocket from "ws";
import { Kafka } from "kafkajs";

const WS_URL = "ws://localhost:8081/ws?token=dev-token";
const KAFKA_BROKER = "localhost:9092";
const TOPIC = "edu.notify.notification.sent";
const USER_ID = "dev-user";

const examEvents = [
  {
    event_type: "ExamExtended",
    data: { examId: "exam-001", extendedMinutes: 15, reason: "special needs" },
  },
  {
    event_type: "ExamForceSubmitted",
    data: { examId: "exam-001", reason: "time_expired", submissionId: "sub-001" },
  },
  {
    event_type: "ExamQuestionReordered",
    data: { examId: "exam-001", questionIds: ["q-3", "q-1", "q-2"] },
  },
];

console.log("[exam-test] connecting WebSocket to", WS_URL);
const ws = new WebSocket(WS_URL);
const received = [];

ws.on("open", async () => {
  console.log("[exam-test] WebSocket connected, publishing 3 exam events...");
  const kafka = new Kafka({ brokers: [KAFKA_BROKER] });
  const producer = kafka.producer();
  await producer.connect();

  for (const ev of examEvents) {
    const payload = {
      event_id: `evt-exam-${ev.event_type}-${Date.now()}`,
      user_id: USER_ID,
      event_type: ev.event_type,
      channel: "ws",
      title: `Exam event: ${ev.event_type}`,
      content: `Verification of ${ev.event_type} passthrough`,
      data: ev.data,
      broadcast: false,
      occurred_at: Date.now(),
    };
    await producer.send({
      topic: TOPIC,
      messages: [{ value: JSON.stringify(payload) }],
    });
    console.log(`[exam-test] published ${ev.event_type}`);
  }
  await producer.disconnect();

  // Wait up to 15 seconds for all 3 messages.
  const deadline = Date.now() + 15000;
  while (Date.now() < deadline && received.length < 3) {
    await new Promise((r) => setTimeout(r, 200));
  }

  if (received.length < 3) {
    console.error(`[exam-test] FAIL: only ${received.length}/3 messages received`);
    process.exit(1);
  }
  const got = received.map((m) => m.event).sort();
  const want = examEvents.map((e) => e.event_type).sort();
  if (JSON.stringify(got) === JSON.stringify(want)) {
    console.log("[exam-test] PASS: all 3 exam events received with correct event_type");
    console.log("[exam-test] events:", got.join(", "));
    process.exit(0);
  } else {
    console.error("[exam-test] FAIL: event mismatch");
    console.error("  got:", got);
    console.error("  want:", want);
    process.exit(1);
  }
});

ws.on("message", (data) => {
  const msg = JSON.parse(data.toString());
  console.log("[exam-test] received:", JSON.stringify(msg));
  received.push(msg);
});
ws.on("error", (err) => {
  console.error("[exam-test] WebSocket error:", err.message);
  process.exit(1);
});

setTimeout(() => {
  console.error("[exam-test] FAIL: overall timeout 20s");
  process.exit(1);
}, 20000);