// FWIW: At the time of this commit, including a timestamp in task increases
// time cost of Push by 3%.
func BenchmarkTaskQueuePush(b *testing.B) {
	q := newPRQ()
	peers := []peer.ID{
		testutil.RandPeerIDFatal(b),
		testutil.RandPeerIDFatal(b),
		testutil.RandPeerIDFatal(b),
	}
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		q.Push(wantlist.Entry{Key: key.Key(i), Priority: math.MaxInt32}, peers[i%len(peers)])
	}
}

// This test checks that peers wont starve out other peers
func TestPeerRepeats(t *testing.T) {
	prq := newPRQ()
	a := testutil.RandPeerIDFatal(t)
	b := testutil.RandPeerIDFatal(t)
	c := testutil.RandPeerIDFatal(t)
	d := testutil.RandPeerIDFatal(t)

	// Have each push some blocks

	for i := 0; i < 5; i++ {
		prq.Push(wantlist.Entry{Key: key.Key(i)}, a)
		prq.Push(wantlist.Entry{Key: key.Key(i)}, b)
		prq.Push(wantlist.Entry{Key: key.Key(i)}, c)
		prq.Push(wantlist.Entry{Key: key.Key(i)}, d)
	}

	// now, pop off four entries, there should be one from each
	var targets []string
	var tasks []*peerRequestTask
	for i := 0; i < 4; i++ {
		t := prq.Pop()
		targets = append(targets, t.Target.Pretty())
		tasks = append(tasks, t)
	}

	expected := []string{a.Pretty(), b.Pretty(), c.Pretty(), d.Pretty()}
	sort.Strings(expected)
	sort.Strings(targets)

	t.Log(targets)
	t.Log(expected)
	for i, s := range targets {
		if expected[i] != s {
			t.Fatal("unexpected peer", s, expected[i])
		}
	}

	// Now, if one of the tasks gets finished, the next task off the queue should
	// be for the same peer
	for blockI := 0; blockI < 4; blockI++ {
		for i := 0; i < 4; i++ {
			// its okay to mark the same task done multiple times here (JUST FOR TESTING)
			tasks[i].Done()

			ntask := prq.Pop()
			if ntask.Target != tasks[i].Target {
				t.Fatal("Expected task from peer with lowest active count")
			}
		}
	}
}

func TestDialBadAddrs(t *testing.T) {

	m := func(s string) ma.Multiaddr {
		maddr, err := ma.NewMultiaddr(s)
		if err != nil {
			t.Fatal(err)
		}
		return maddr
	}

	ctx := context.Background()
	s := makeSwarms(ctx, t, 1)[0]

	test := func(a ma.Multiaddr) {
		p := testutil.RandPeerIDFatal(t)
		s.peers.AddAddr(p, a, peer.PermanentAddrTTL)
		if _, err := s.Dial(ctx, p); err == nil {
			t.Error("swarm should not dial: %s", m)
		}
	}

	test(m("/ip6/fe80::1"))                // link local
	test(m("/ip6/fe80::100"))              // link local
	test(m("/ip4/127.0.0.1/udp/1234/utp")) // utp
}

func TestTableFindMultiple(t *testing.T) {
	local := tu.RandPeerIDFatal(t)
	m := peer.NewMetrics()
	rt := NewRoutingTable(20, ConvertPeerID(local), time.Hour, m)

	peers := make([]peer.ID, 100)
	for i := 0; i < 18; i++ {
		peers[i] = tu.RandPeerIDFatal(t)
		rt.Update(peers[i])
	}

	t.Logf("Searching for peer: '%s'", peers[2])
	found := rt.NearestPeers(ConvertPeerID(peers[2]), 15)
	if len(found) != 15 {
		t.Fatalf("Got back different number of peers than we expected.")
	}
}

func TestTableFind(t *testing.T) {
	local := tu.RandPeerIDFatal(t)
	m := peer.NewMetrics()
	rt := NewRoutingTable(10, ConvertPeerID(local), time.Hour, m)

	peers := make([]peer.ID, 100)
	for i := 0; i < 5; i++ {
		peers[i] = tu.RandPeerIDFatal(t)
		rt.Update(peers[i])
	}

	t.Logf("Searching for peer: '%s'", peers[2])
	found := rt.NearestPeer(ConvertPeerID(peers[2]))
	if !(found == peers[2]) {
		t.Fatalf("Failed to lookup known node...")
	}
}

func TestPushPop(t *testing.T) {
	prq := newPRQ()
	partner := testutil.RandPeerIDFatal(t)
	alphabet := strings.Split("abcdefghijklmnopqrstuvwxyz", "")
	vowels := strings.Split("aeiou", "")
	consonants := func() []string {
		var out []string
		for _, letter := range alphabet {
			skip := false
			for _, vowel := range vowels {
				if letter == vowel {
					skip = true
				}
			}
			if !skip {
				out = append(out, letter)
			}
		}
		return out
	}()
	sort.Strings(alphabet)
	sort.Strings(vowels)
	sort.Strings(consonants)

	// add a bunch of blocks. cancel some. drain the queue. the queue should only have the kept entries

	for _, index := range rand.Perm(len(alphabet)) { // add blocks for all letters
		letter := alphabet[index]
		t.Log(partner.String())
		prq.Push(wantlist.Entry{Key: key.Key(letter), Priority: math.MaxInt32 - index}, partner)
	}
	for _, consonant := range consonants {
		prq.Remove(key.Key(consonant), partner)
	}

	var out []string
	for {
		received := prq.Pop()
		if received == nil {
			break
		}

		out = append(out, string(received.Entry.Key))
	}

	// Entries popped should already be in correct order
	for i, expected := range vowels {
		if out[i] != expected {
			t.Fatal("received", out[i], "expected", expected)
		}
	}
}

// Right now, this just makes sure that it doesnt hang or crash
func TestTableUpdate(t *testing.T) {
	local := tu.RandPeerIDFatal(t)
	m := peer.NewMetrics()
	rt := NewRoutingTable(10, ConvertPeerID(local), time.Hour, m)

	peers := make([]peer.ID, 100)
	for i := 0; i < 100; i++ {
		peers[i] = tu.RandPeerIDFatal(t)
	}

	// Testing Update
	for i := 0; i < 10000; i++ {
		rt.Update(peers[rand.Intn(len(peers))])
	}

	for i := 0; i < 100; i++ {
		id := ConvertPeerID(tu.RandPeerIDFatal(t))
		ret := rt.NearestPeers(id, 5)
		if len(ret) == 0 {
			t.Fatal("Failed to find node near ID.")
		}
	}
}

// Test basic features of the bucket struct
func TestBucket(t *testing.T) {
	b := newBucket()

	peers := make([]peer.ID, 100)
	for i := 0; i < 100; i++ {
		peers[i] = tu.RandPeerIDFatal(t)
		b.PushFront(peers[i])
	}

	local := tu.RandPeerIDFatal(t)
	localID := ConvertPeerID(local)

	i := rand.Intn(len(peers))
	if !b.Has(peers[i]) {
		t.Errorf("Failed to find peer: %v", peers[i])
	}

	spl := b.Split(0, ConvertPeerID(local))
	llist := b.list
	for e := llist.Front(); e != nil; e = e.Next() {
		p := ConvertPeerID(e.Value.(peer.ID))
		cpl := commonPrefixLen(p, localID)
		if cpl > 0 {
			t.Fatalf("Split failed. found id with cpl > 0 in 0 bucket")
		}
	}

	rlist := spl.list
	for e := rlist.Front(); e != nil; e = e.Next() {
		p := ConvertPeerID(e.Value.(peer.ID))
		cpl := commonPrefixLen(p, localID)
		if cpl == 0 {
			t.Fatalf("Split failed. found id with cpl == 0 in non 0 bucket")
		}
	}
}

func BenchmarkUpdates(b *testing.B) {
	b.StopTimer()
	local := ConvertKey("localKey")
	m := peer.NewMetrics()
	tab := NewRoutingTable(20, local, time.Hour, m)

	var peers []peer.ID
	for i := 0; i < b.N; i++ {
		peers = append(peers, tu.RandPeerIDFatal(b))
	}

	b.StartTimer()
	for i := 0; i < b.N; i++ {
		tab.Update(peers[i])
	}
}

func newSilentPeer(t *testing.T) (peer.ID, ma.Multiaddr, net.Listener) {
	dst := testutil.RandPeerIDFatal(t)
	lst, err := net.Listen("tcp", ":0")
	if err != nil {
		t.Fatal(err)
	}
	addr, err := manet.FromNetAddr(lst.Addr())
	if err != nil {
		t.Fatal(err)
	}
	addrs := []ma.Multiaddr{addr}
	addrs, err = addrutil.ResolveUnspecifiedAddresses(addrs, nil)
	if err != nil {
		t.Fatal(err)
	}
	t.Log("new silent peer:", dst, addrs[0])
	return dst, addrs[0], lst
}

func TestPartnerWantsThenCancels(t *testing.T) {
	numRounds := 10
	if testing.Short() {
		numRounds = 1
	}
	alphabet := strings.Split("abcdefghijklmnopqrstuvwxyz", "")
	vowels := strings.Split("aeiou", "")

	type testCase [][]string
	testcases := []testCase{
		{
			alphabet, vowels,
		},
		{
			alphabet, stringsComplement(alphabet, vowels),
		},
	}

	bs := blockstore.NewBlockstore(dssync.MutexWrap(ds.NewMapDatastore()))
	for _, letter := range alphabet {
		block := blocks.NewBlock([]byte(letter))
		if err := bs.Put(block); err != nil {
			t.Fatal(err)
		}
	}

	for i := 0; i < numRounds; i++ {
		for _, testcase := range testcases {
			set := testcase[0]
			cancels := testcase[1]
			keeps := stringsComplement(set, cancels)

			e := NewEngine(context.Background(), bs)
			partner := testutil.RandPeerIDFatal(t)

			partnerWants(e, set, partner)
			partnerCancels(e, cancels, partner)
			if err := checkHandledInOrder(t, e, keeps); err != nil {
				t.Logf("run #%d of %d", i, numRounds)
				t.Fatal(err)
			}
		}
	}
}

// Looks for race conditions in table operations. For a more 'certain'
// test, increase the loop counter from 1000 to a much higher number
// and set GOMAXPROCS above 1
func TestTableMultithreaded(t *testing.T) {
	local := peer.ID("localPeer")
	m := peer.NewMetrics()
	tab := NewRoutingTable(20, ConvertPeerID(local), time.Hour, m)
	var peers []peer.ID
	for i := 0; i < 500; i++ {
		peers = append(peers, tu.RandPeerIDFatal(t))
	}

	done := make(chan struct{})
	go func() {
		for i := 0; i < 1000; i++ {
			n := rand.Intn(len(peers))
			tab.Update(peers[n])
		}
		done <- struct{}{}
	}()

	go func() {
		for i := 0; i < 1000; i++ {
			n := rand.Intn(len(peers))
			tab.Update(peers[n])
		}
		done <- struct{}{}
	}()

	go func() {
		for i := 0; i < 1000; i++ {
			n := rand.Intn(len(peers))
			tab.Find(peers[n])
		}
		done <- struct{}{}
	}()
	<-done
	<-done
	<-done
}