package edu.ics211.h08;

import static org.junit.jupiter.api.Assertions.*;

import java.util.List;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

/**
 * JUnit tests for the Router class.
 *
 * @author esb@hawaii.edu
 *
 */
class RouterTest {

	private Router router;
	private List<Packet> sent;
	private List<Packet> packets;

	private class Sender implements PacketSenderInterface {
		public void send(int queue, Packet p) {
			sent.add(p);
			// System.out.println ("sending packet " + p + " on queue " + queue);
		}
	}

	/**
	 * @throws java.lang.Exception
	 */
	@BeforeEach
	void setUp() throws Exception {
		router = new Router(new Sender());
		sent = new java.util.LinkedList<Packet>();
		packets = new java.util.LinkedList<Packet>();
	}

	@Test
	void test() {
		assertNotNull(router);
		assertNotNull(sent);
		// test each of the queues
		for (int q = 0; q < 7; q++) {
			// send 7 packets, all to queue q
			Packet p = new Packet(q);
			packets.add(p);
			assertNotNull(p);
			for (int i = 0; i < 7; i++) {
				assertTrue(router.acceptPacket(p));
			}
			sent.clear();          // see which packets we send
			router.advanceTime();  // send the first packet in all the queues that have packets
			// every queue 0..q-1 should have packets to send, except once we get to queue 6,
			// the first queue should have already sent all its 10 packets (because
			// for each value of q, we call router.advanceTime() twice)
			final int expectedSend = (q <= 5) ? q + 1 : q;
			assertEquals(sent.size(), expectedSend);
			if (q <= 5) {  // there should be a packet from each queue
				for (Packet checkP: packets) {
					assertTrue(sent.contains(checkP));
				}
			} else {       // at least check that the latest packet was sent
				assertTrue(sent.contains(p));
			}
			sent.clear();
			// should be 6 packets in queue q.  Send 4 more
			for (int i = 0; i < 4; i++) {
				assertTrue(router.acceptPacket(p));
			}
			// now queue q should be full.  See if the packet is dropped
			assertFalse(router.acceptPacket(p));
			router.advanceTime();  // send the first packet in every queue that has packets
			assertEquals(sent.size(), expectedSend);
			if (q <= 5) {  // there should be a packet from each queue
				for (Packet checkP: packets) {
					assertTrue(sent.contains(checkP));
				}
			} else {       // at least check that the lastest packet was sent
				assertTrue(sent.contains(p));
			}
			sent.clear();
			// should be able to add one more to queue q, then the next should be dropped
			assertTrue(router.acceptPacket(p));
			assertFalse(router.acceptPacket(p));
			// we end this loop with 10 packets on queue q, 9 on queue i - 1, etc
		}
	}

}