func TestClientFindProviders(t *testing.T) {
	pi := testutil.RandIdentityOrFatal(t)
	rs := NewServer()
	client := rs.Client(pi)

	k := key.Key("hello")
	err := client.Provide(context.Background(), k)
	if err != nil {
		t.Fatal(err)
	}

	// This is bad... but simulating networks is hard
	time.Sleep(time.Millisecond * 300)
	max := 100

	providersFromClient := client.FindProvidersAsync(context.Background(), key.Key("hello"), max)
	isInClient := false
	for pi := range providersFromClient {
		if pi.ID == pi.ID {
			isInClient = true
		}
	}
	if !isInClient {
		t.Fatal("Despite client providing key, client didn't receive peer when finding providers")
	}
}

func TestToNetFromNetPreservesWantList(t *testing.T) {
	original := New(true)
	original.AddEntry(key.Key("M"), 1)
	original.AddEntry(key.Key("B"), 1)
	original.AddEntry(key.Key("D"), 1)
	original.AddEntry(key.Key("T"), 1)
	original.AddEntry(key.Key("F"), 1)

	buf := new(bytes.Buffer)
	if err := original.ToNet(buf); err != nil {
		t.Fatal(err)
	}

	copied, err := FromNet(buf)
	if err != nil {
		t.Fatal(err)
	}

	keys := make(map[key.Key]bool)
	for _, k := range copied.Wantlist() {
		keys[k.Key] = true
	}

	for _, k := range original.Wantlist() {
		if _, ok := keys[k.Key]; !ok {
			t.Fatalf("Key Missing: \"%v\"", k)
		}
	}
}

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)
		}
	}
}

// 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")
			}
		}
	}
}

// GetNode returns the MDAG Node that this link points to
func (l *Link) GetNode(ctx context.Context, serv DAGService) (*Node, error) {
	if l.Node != nil {
		return l.Node, nil
	}

	return serv.Get(ctx, key.Key(l.Hash))
}

// VerifyRecord checks a record and ensures it is still valid.
// It runs needed validators
func (v Validator) VerifyRecord(r *pb.Record) error {
	// Now, check validity func
	parts := strings.Split(r.GetKey(), "/")
	if len(parts) < 3 {
		log.Infof("Record key does not have validator: %s", key.Key(r.GetKey()))
		return nil
	}

	val, ok := v[parts[1]]
	if !ok {
		log.Infof("Unrecognized key prefix: %s", parts[1])
		return ErrInvalidRecordType
	}

	return val.Func(key.Key(r.GetKey()), r.GetValue())
}

// putProvider sends a message to peer 'p' saying that the local node
// can provide the value of 'key'
func (dht *IpfsDHT) putProvider(ctx context.Context, p peer.ID, skey string) error {

	// add self as the provider
	pi := peer.PeerInfo{
		ID:    dht.self,
		Addrs: dht.host.Addrs(),
	}

	// // only share WAN-friendly addresses ??
	// pi.Addrs = addrutil.WANShareableAddrs(pi.Addrs)
	if len(pi.Addrs) < 1 {
		// log.Infof("%s putProvider: %s for %s error: no wan-friendly addresses", dht.self, p, key.Key(key), pi.Addrs)
		return fmt.Errorf("no known addresses for self. cannot put provider.")
	}

	pmes := pb.NewMessage(pb.Message_ADD_PROVIDER, skey, 0)
	pmes.ProviderPeers = pb.RawPeerInfosToPBPeers([]peer.PeerInfo{pi})
	err := dht.sendMessage(ctx, p, pmes)
	if err != nil {
		return err
	}

	log.Debugf("%s putProvider: %s for %s (%s)", dht.self, p, key.Key(skey), pi.Addrs)
	return nil
}

// betterPeerToQuery returns nearestPeersToQuery, but iff closer than self.
func (dht *IpfsDHT) betterPeersToQuery(pmes *pb.Message, p peer.ID, count int) []peer.ID {
	closer := dht.nearestPeersToQuery(pmes, count)

	// no node? nil
	if closer == nil {
		return nil
	}

	// == to self? thats bad
	for _, p := range closer {
		if p == dht.self {
			log.Debug("Attempted to return self! this shouldnt happen...")
			return nil
		}
	}

	var filtered []peer.ID
	for _, clp := range closer {
		// Dont send a peer back themselves
		if p == clp {
			continue
		}

		// must all be closer than self
		key := key.Key(pmes.GetKey())
		if !kb.Closer(dht.self, clp, key) {
			filtered = append(filtered, clp)
		}
	}

	// ok seems like closer nodes
	return filtered
}

func TestValidAfter(t *testing.T) {

	pi := testutil.RandIdentityOrFatal(t)
	var key = key.Key("mock key")
	var ctx = context.Background()
	conf := DelayConfig{
		ValueVisibility: delay.Fixed(1 * time.Hour),
		Query:           delay.Fixed(0),
	}

	rs := NewServerWithDelay(conf)

	rs.Client(pi).Provide(ctx, key)

	var providers []peer.PeerInfo
	providers, err := rs.Client(pi).FindProviders(ctx, key)
	if err != nil {
		t.Fatal(err)
	}
	if len(providers) > 0 {
		t.Fail()
	}

	conf.ValueVisibility.Set(0)
	providers, err = rs.Client(pi).FindProviders(ctx, key)
	if err != nil {
		t.Fatal(err)
	}
	t.Log("providers", providers)
	if len(providers) != 1 {
		t.Fail()
	}
}

func TestClientOverMax(t *testing.T) {
	rs := NewServer()
	k := key.Key("hello")
	numProvidersForHelloKey := 100
	for i := 0; i < numProvidersForHelloKey; i++ {
		pi := testutil.RandIdentityOrFatal(t)
		err := rs.Client(pi).Provide(context.Background(), k)
		if err != nil {
			t.Fatal(err)
		}
	}

	max := 10
	pi := testutil.RandIdentityOrFatal(t)
	client := rs.Client(pi)

	providersFromClient := client.FindProvidersAsync(context.Background(), k, max)
	i := 0
	for _ = range providersFromClient {
		i++
	}
	if i != max {
		t.Fatal("Too many providers returned")
	}
}

func (dht *IpfsDHT) handleAddProvider(ctx context.Context, p peer.ID, pmes *pb.Message) (*pb.Message, error) {
	lm := make(lgbl.DeferredMap)
	lm["peer"] = func() interface{} { return p.Pretty() }

	defer log.EventBegin(ctx, "handleAddProvider", lm).Done()
	key := key.Key(pmes.GetKey())
	lm["key"] = func() interface{} { return key.Pretty() }

	log.Debugf("%s adding %s as a provider for '%s'\n", dht.self, p, key)

	// add provider should use the address given in the message
	pinfos := pb.PBPeersToPeerInfos(pmes.GetProviderPeers())
	for _, pi := range pinfos {
		if pi.ID != p {
			// we should ignore this provider reccord! not from originator.
			// (we chould sign them and check signature later...)
			log.Debugf("handleAddProvider received provider %s from %s. Ignore.", pi.ID, p)
			continue
		}

		if len(pi.Addrs) < 1 {
			log.Debugf("%s got no valid addresses for provider %s. Ignore.", dht.self, p)
			continue
		}

		log.Infof("received provider %s for %s (addrs: %s)", p, key, pi.Addrs)
		if pi.ID != dht.self { // dont add own addrs.
			// add the received addresses to our peerstore.
			dht.peerstore.AddAddrs(pi.ID, pi.Addrs, peer.ProviderAddrTTL)
		}
		dht.providers.AddProvider(ctx, key, p)
	}

	return nil, nil
}

func TestBlockReturnsErr(t *testing.T) {
	off := Exchange(bstore())
	_, err := off.GetBlock(context.Background(), key.Key("foo"))
	if err != nil {
		return // as desired
	}
	t.Fail()
}

// Loggable turns a Message into machine-readable log output
func (m *Message) Loggable() map[string]interface{} {
	return map[string]interface{}{
		"message": map[string]string{
			"type": m.Type.String(),
			"key":  key.Key(m.GetKey()).Pretty(),
		},
	}
}

func init() {
	testCaseValues["hello"] = []byte("world")
	for i := 0; i < 100; i++ {
		k := fmt.Sprintf("%d -- key", i)
		v := fmt.Sprintf("%d -- value", i)
		testCaseValues[key.Key(k)] = []byte(v)
	}
}

func TestCopyProtoByValue(t *testing.T) {
	const str = "foo"
	m := New(true)
	protoBeforeAppend := m.ToProto()
	m.AddEntry(key.Key(str), 1)
	if wantlistContains(protoBeforeAppend.GetWantlist(), str) {
		t.Fail()
	}
}

// Store a value in this peer local storage
func (dht *IpfsDHT) handlePutValue(ctx context.Context, p peer.ID, pmes *pb.Message) (*pb.Message, error) {
	defer log.EventBegin(ctx, "handlePutValue", p).Done()
	dskey := key.Key(pmes.GetKey()).DsKey()

	if err := dht.verifyRecordLocally(pmes.GetRecord()); err != nil {
		log.Debugf("Bad dht record in PUT from: %s. %s", key.Key(pmes.GetRecord().GetAuthor()), err)
		return nil, err
	}

	data, err := proto.Marshal(pmes.GetRecord())
	if err != nil {
		return nil, err
	}

	err = dht.datastore.Put(dskey, data)
	log.Debugf("%s handlePutValue %v", dht.self, dskey)
	return pmes, err
}

// TODO does dht ensure won't receive self as a provider? probably not.
func TestCanceledContext(t *testing.T) {
	rs := NewServer()
	k := key.Key("hello")

	// avoid leaking goroutine, without using the context to signal
	// (we want the goroutine to keep trying to publish on a
	// cancelled context until we've tested it doesnt do anything.)
	done := make(chan struct{})
	defer func() { done <- struct{}{} }()

	t.Log("async'ly announce infinite stream of providers for key")
	i := 0
	go func() { // infinite stream
		for {
			select {
			case <-done:
				t.Log("exiting async worker")
				return
			default:
			}

			pi, err := testutil.RandIdentity()
			if err != nil {
				t.Error(err)
			}
			err = rs.Client(pi).Provide(context.Background(), k)
			if err != nil {
				t.Error(err)
			}
			i++
		}
	}()

	local := testutil.RandIdentityOrFatal(t)
	client := rs.Client(local)

	t.Log("warning: max is finite so this test is non-deterministic")
	t.Log("context cancellation could simply take lower priority")
	t.Log("and result in receiving the max number of results")
	max := 1000

	t.Log("cancel the context before consuming")
	ctx, cancelFunc := context.WithCancel(context.Background())
	cancelFunc()
	providers := client.FindProvidersAsync(ctx, k, max)

	numProvidersReturned := 0
	for _ = range providers {
		numProvidersReturned++
	}
	t.Log(numProvidersReturned)

	if numProvidersReturned == max {
		t.Fatal("Context cancel had no effect")
	}
}

func TestAppendWanted(t *testing.T) {
	const str = "foo"
	m := New(true)
	m.AddEntry(key.Key(str), 1)

	if !wantlistContains(m.ToProto().GetWantlist(), str) {
		t.Fail()
	}
	m.ToProto().GetWantlist().GetEntries()
}

func newMessageFromProto(pbm pb.Message) BitSwapMessage {
	m := newMsg(pbm.GetWantlist().GetFull())
	for _, e := range pbm.GetWantlist().GetEntries() {
		m.addEntry(key.Key(e.GetBlock()), int(e.GetPriority()), e.GetCancel())
	}
	for _, d := range pbm.GetBlocks() {
		b := blocks.NewBlock(d)
		m.AddBlock(b)
	}
	return m
}

func TestProviderManager(t *testing.T) {
	ctx := context.Background()
	mid := peer.ID("testing")
	p := NewProviderManager(ctx, mid)
	a := key.Key("test")
	p.AddProvider(ctx, a, peer.ID("testingprovider"))
	resp := p.GetProviders(ctx, a)
	if len(resp) != 1 {
		t.Fatal("Could not retrieve provider.")
	}
	p.proc.Close()
}