func TestGetBlockFromPeerAfterPeerAnnounces(t *testing.T) {

	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	block := blocks.NewBlock([]byte("block"))
	g := NewTestSessionGenerator(net)
	defer g.Close()

	peers := g.Instances(2)
	hasBlock := peers[0]
	defer hasBlock.Exchange.Close()

	if err := hasBlock.Exchange.HasBlock(block); err != nil {
		t.Fatal(err)
	}

	wantsBlock := peers[1]
	defer wantsBlock.Exchange.Close()

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	received, err := wantsBlock.Exchange.GetBlock(ctx, block.Key())
	if err != nil {
		t.Log(err)
		t.Fatal("Expected to succeed")
	}

	if !bytes.Equal(block.Data, received.Data) {
		t.Fatal("Data doesn't match")
	}
}

func TestBasicBitswap(t *testing.T) {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	t.Log("Test a one node trying to get one block from another")

	instances := sg.Instances(2)
	blocks := bg.Blocks(1)
	err := instances[0].Exchange.HasBlock(blocks[0])
	if err != nil {
		t.Fatal(err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
	defer cancel()
	blk, err := instances[1].Exchange.GetBlock(ctx, blocks[0].Key())
	if err != nil {
		t.Fatal(err)
	}

	t.Log(blk)
	for _, inst := range instances {
		err := inst.Exchange.Close()
		if err != nil {
			t.Fatal(err)
		}
	}
}

func TestRoutingResolve(t *testing.T) {
	dstore := dssync.MutexWrap(ds.NewMapDatastore())
	serv := mockrouting.NewServer()
	id := testutil.RandIdentityOrFatal(t)
	d := serv.ClientWithDatastore(context.Background(), id, dstore)

	resolver := NewRoutingResolver(d, 0)
	publisher := NewRoutingPublisher(d, dstore)

	privk, pubk, err := testutil.RandTestKeyPair(512)
	if err != nil {
		t.Fatal(err)
	}

	h := path.FromString("/ipfs/QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN")
	err = publisher.Publish(context.Background(), privk, h)
	if err != nil {
		t.Fatal(err)
	}

	pid, err := peer.IDFromPublicKey(pubk)
	if err != nil {
		t.Fatal(err)
	}

	res, err := resolver.Resolve(context.Background(), pid.Pretty())
	if err != nil {
		t.Fatal(err)
	}

	if res != h {
		t.Fatal("Got back incorrect value.")
	}
}

func TestRoutingResolve(t *testing.T) {
	d := mockrouting.NewServer().Client(testutil.RandIdentityOrFatal(t))
	dstore := ds.NewMapDatastore()

	resolver := NewRoutingResolver(d, 0)
	publisher := NewRoutingPublisher(d, dstore)

	privk, pubk, err := testutil.RandTestKeyPair(512)
	if err != nil {
		t.Fatal(err)
	}

	h := path.FromString("/ipfs/QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN")
	err = publisher.Publish(context.Background(), privk, h)
	if err != nil {
		t.Fatal(err)
	}

	pubkb, err := pubk.Bytes()
	if err != nil {
		t.Fatal(err)
	}

	pkhash := u.Hash(pubkb)
	res, err := resolver.Resolve(context.Background(), key.Key(pkhash).Pretty())
	if err != nil {
		t.Fatal(err)
	}

	if res != h {
		t.Fatal("Got back incorrect value.")
	}
}

func TestDoubleGet(t *testing.T) {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	t.Log("Test a one node trying to get one block from another")

	instances := sg.Instances(2)
	blocks := bg.Blocks(1)

	ctx1, cancel1 := context.WithCancel(context.Background())
	blkch1, err := instances[1].Exchange.GetBlocks(ctx1, []*cid.Cid{blocks[0].Cid()})
	if err != nil {
		t.Fatal(err)
	}

	ctx2, cancel2 := context.WithCancel(context.Background())
	defer cancel2()

	blkch2, err := instances[1].Exchange.GetBlocks(ctx2, []*cid.Cid{blocks[0].Cid()})
	if err != nil {
		t.Fatal(err)
	}

	// ensure both requests make it into the wantlist at the same time
	time.Sleep(time.Millisecond * 100)
	cancel1()

	_, ok := <-blkch1
	if ok {
		t.Fatal("expected channel to be closed")
	}

	err = instances[0].Exchange.HasBlock(blocks[0])
	if err != nil {
		t.Fatal(err)
	}

	select {
	case blk, ok := <-blkch2:
		if !ok {
			t.Fatal("expected to get the block here")
		}
		t.Log(blk)
	case <-time.After(time.Second * 5):
		t.Fatal("timed out waiting on block")
	}

	for _, inst := range instances {
		err := inst.Exchange.Close()
		if err != nil {
			t.Fatal(err)
		}
	}
}

func TestEmptyKey(t *testing.T) {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bs := sg.Instances(1)[0].Exchange

	_, err := bs.GetBlock(context.Background(), key.Key(""))
	if err != blockstore.ErrNotFound {
		t.Error("empty str key should return ErrNotFound")
	}
}

// Mocks returns |n| connected mock Blockservices
func Mocks(n int) []BlockService {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(0))
	sg := bitswap.NewTestSessionGenerator(net)

	instances := sg.Instances(n)

	var servs []BlockService
	for _, i := range instances {
		servs = append(servs, New(i.Blockstore(), i.Exchange))
	}
	return servs
}

func TestClose(t *testing.T) {
	vnet := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sesgen := NewTestSessionGenerator(vnet)
	defer sesgen.Close()
	bgen := blocksutil.NewBlockGenerator()

	block := bgen.Next()
	bitswap := sesgen.Next()

	bitswap.Exchange.Close()
	bitswap.Exchange.GetBlock(context.Background(), block.Key())
}

// TODO simplify this test. get to the _essence_!
func TestSendToWantingPeer(t *testing.T) {
	if testing.Short() {
		t.SkipNow()
	}

	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	prev := rebroadcastDelay.Set(time.Second / 2)
	defer func() { rebroadcastDelay.Set(prev) }()

	peers := sg.Instances(2)
	peerA := peers[0]
	peerB := peers[1]

	t.Logf("Session %v\n", peerA.Peer)
	t.Logf("Session %v\n", peerB.Peer)

	timeout := time.Second
	waitTime := time.Second * 5

	alpha := bg.Next()
	// peerA requests and waits for block alpha
	ctx, cancel := context.WithTimeout(context.Background(), waitTime)
	defer cancel()
	alphaPromise, err := peerA.Exchange.GetBlocks(ctx, []key.Key{alpha.Key()})
	if err != nil {
		t.Fatal(err)
	}

	// peerB announces to the network that he has block alpha
	ctx, cancel = context.WithTimeout(context.Background(), timeout)
	defer cancel()
	err = peerB.Exchange.HasBlock(ctx, alpha)
	if err != nil {
		t.Fatal(err)
	}

	// At some point, peerA should get alpha (or timeout)
	blkrecvd, ok := <-alphaPromise
	if !ok {
		t.Fatal("context timed out and broke promise channel!")
	}

	if blkrecvd.Key() != alpha.Key() {
		t.Fatal("Wrong block!")
	}

}

func TestSendMessageAsyncButWaitForResponse(t *testing.T) {
	net := VirtualNetwork(mockrouting.NewServer(), delay.Fixed(0))
	responderPeer := testutil.RandIdentityOrFatal(t)
	waiter := net.Adapter(testutil.RandIdentityOrFatal(t))
	responder := net.Adapter(responderPeer)

	var wg sync.WaitGroup

	wg.Add(1)

	expectedStr := "received async"

	responder.SetDelegate(lambda(func(
		ctx context.Context,
		fromWaiter peer.ID,
		msgFromWaiter bsmsg.BitSwapMessage) {

		msgToWaiter := bsmsg.New(true)
		msgToWaiter.AddBlock(blocks.NewBlock([]byte(expectedStr)))
		waiter.SendMessage(ctx, fromWaiter, msgToWaiter)
	}))

	waiter.SetDelegate(lambda(func(
		ctx context.Context,
		fromResponder peer.ID,
		msgFromResponder bsmsg.BitSwapMessage) {

		// TODO assert that this came from the correct peer and that the message contents are as expected
		ok := false
		for _, b := range msgFromResponder.Blocks() {
			if string(b.Data) == expectedStr {
				wg.Done()
				ok = true
			}
		}

		if !ok {
			t.Fatal("Message not received from the responder")
		}
	}))

	messageSentAsync := bsmsg.New(true)
	messageSentAsync.AddBlock(blocks.NewBlock([]byte("data")))
	errSending := waiter.SendMessage(
		context.Background(), responderPeer.ID(), messageSentAsync)
	if errSending != nil {
		t.Fatal(errSending)
	}

	wg.Wait() // until waiter delegate function is executed
}

func PerformDistributionTest(t *testing.T, numInstances, numBlocks int) {
	ctx := context.Background()
	if testing.Short() {
		t.SkipNow()
	}
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	instances := sg.Instances(numInstances)
	blocks := bg.Blocks(numBlocks)

	t.Log("Give the blocks to the first instance")

	var blkeys []key.Key
	first := instances[0]
	for _, b := range blocks {
		blkeys = append(blkeys, b.Key())
		first.Exchange.HasBlock(ctx, b)
	}

	t.Log("Distribute!")

	wg := sync.WaitGroup{}
	for _, inst := range instances[1:] {
		wg.Add(1)
		go func(inst Instance) {
			defer wg.Done()
			outch, err := inst.Exchange.GetBlocks(ctx, blkeys)
			if err != nil {
				t.Fatal(err)
			}
			for _ = range outch {
			}
		}(inst)
	}
	wg.Wait()

	t.Log("Verify!")

	for _, inst := range instances {
		for _, b := range blocks {
			if _, err := inst.Blockstore().Get(b.Key()); err != nil {
				t.Fatal(err)
			}
		}
	}
}

// Mocks returns |n| connected mock Blockservices
func Mocks(t fataler, n int) []*BlockService {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(0))
	sg := bitswap.NewTestSessionGenerator(net)

	instances := sg.Instances(n)

	var servs []*BlockService
	for _, i := range instances {
		bserv, err := New(i.Blockstore(), i.Exchange)
		if err != nil {
			t.Fatal(err)
		}
		servs = append(servs, bserv)
	}
	return servs
}

func TestProviderForKeyButNetworkCannotFind(t *testing.T) { // TODO revisit this

	rs := mockrouting.NewServer()
	net := tn.VirtualNetwork(rs, delay.Fixed(kNetworkDelay))
	g := NewTestSessionGenerator(net)
	defer g.Close()

	block := blocks.NewBlock([]byte("block"))
	pinfo := p2ptestutil.RandTestBogusIdentityOrFatal(t)
	rs.Client(pinfo).Provide(context.Background(), block.Key()) // but not on network

	solo := g.Next()
	defer solo.Exchange.Close()

	ctx, _ := context.WithTimeout(context.Background(), time.Nanosecond)
	_, err := solo.Exchange.GetBlock(ctx, block.Key())

	if err != context.DeadlineExceeded {
		t.Fatal("Expected DeadlineExceeded error")
	}
}

func TestReprovide(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	mrserv := mock.NewServer()

	idA := testutil.RandIdentityOrFatal(t)
	idB := testutil.RandIdentityOrFatal(t)

	clA := mrserv.Client(idA)
	clB := mrserv.Client(idB)

	bstore := blockstore.NewBlockstore(dssync.MutexWrap(ds.NewMapDatastore()))

	blk := blocks.NewBlock([]byte("this is a test"))
	bstore.Put(blk)

	reprov := NewReprovider(clA, bstore)
	err := reprov.Reprovide(ctx)
	if err != nil {
		t.Fatal(err)
	}

	provs, err := clB.FindProviders(ctx, blk.Key())
	if err != nil {
		t.Fatal(err)
	}

	if len(provs) == 0 {
		t.Fatal("Should have gotten a provider")
	}

	if provs[0].ID != idA.ID() {
		t.Fatal("Somehow got the wrong peer back as a provider.")
	}
}

func TestPrexistingRecord(t *testing.T) {
	dstore := ds.NewMapDatastore()
	d := mockrouting.NewServer().ClientWithDatastore(context.Background(), testutil.RandIdentityOrFatal(t), dstore)

	resolver := NewRoutingResolver(d, 0)
	publisher := NewRoutingPublisher(d, dstore)

	privk, pubk, err := testutil.RandTestKeyPair(512)
	if err != nil {
		t.Fatal(err)
	}

	id, err := peer.IDFromPublicKey(pubk)
	if err != nil {
		t.Fatal(err)
	}

	// Make a good record and put it in the datastore
	h := path.FromString("/ipfs/QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN")
	eol := time.Now().Add(time.Hour)
	err = PutRecordToRouting(context.Background(), privk, h, 0, eol, d, id)
	if err != nil {
		t.Fatal(err)
	}

	// Now, with an old record in the system already, try and publish a new one
	err = publisher.Publish(context.Background(), privk, h)
	if err != nil {
		t.Fatal(err)
	}

	err = verifyCanResolve(resolver, id.Pretty(), h)
	if err != nil {
		t.Fatal(err)
	}
}

func getVirtualNetwork() tn.Network {
	return tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
}

func TestWantlistCleanup(t *testing.T) {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	instances := sg.Instances(1)[0]
	bswap := instances.Exchange
	blocks := bg.Blocks(20)

	var keys []*cid.Cid
	for _, b := range blocks {
		keys = append(keys, b.Cid())
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*50)
	defer cancel()
	_, err := bswap.GetBlock(ctx, keys[0])
	if err != context.DeadlineExceeded {
		t.Fatal("shouldnt have fetched any blocks")
	}

	time.Sleep(time.Millisecond * 50)

	if len(bswap.GetWantlist()) > 0 {
		t.Fatal("should not have anyting in wantlist")
	}

	ctx, cancel = context.WithTimeout(context.Background(), time.Millisecond*50)
	defer cancel()
	_, err = bswap.GetBlocks(ctx, keys[:10])
	if err != nil {
		t.Fatal(err)
	}

	<-ctx.Done()
	time.Sleep(time.Millisecond * 50)

	if len(bswap.GetWantlist()) > 0 {
		t.Fatal("should not have anyting in wantlist")
	}

	_, err = bswap.GetBlocks(context.Background(), keys[:1])
	if err != nil {
		t.Fatal(err)
	}

	ctx, cancel = context.WithCancel(context.Background())
	_, err = bswap.GetBlocks(ctx, keys[10:])
	if err != nil {
		t.Fatal(err)
	}

	time.Sleep(time.Millisecond * 50)
	if len(bswap.GetWantlist()) != 11 {
		t.Fatal("should have 11 keys in wantlist")
	}

	cancel()
	time.Sleep(time.Millisecond * 50)
	if !(len(bswap.GetWantlist()) == 1 && bswap.GetWantlist()[0] == keys[0]) {
		t.Fatal("should only have keys[0] in wantlist")
	}
}

func PerformDistributionTest(t *testing.T, numInstances, numBlocks int) {
	ctx := context.Background()
	if testing.Short() {
		t.SkipNow()
	}
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	instances := sg.Instances(numInstances)
	blocks := bg.Blocks(numBlocks)

	t.Log("Give the blocks to the first instance")

	nump := len(instances) - 1
	// assert we're properly connected
	for _, inst := range instances {
		peers := inst.Exchange.wm.ConnectedPeers()
		for i := 0; i < 10 && len(peers) != nump; i++ {
			time.Sleep(time.Millisecond * 50)
			peers = inst.Exchange.wm.ConnectedPeers()
		}
		if len(peers) != nump {
			t.Fatal("not enough peers connected to instance")
		}
	}

	var blkeys []key.Key
	first := instances[0]
	for _, b := range blocks {
		blkeys = append(blkeys, b.Key())
		first.Exchange.HasBlock(b)
	}

	t.Log("Distribute!")

	wg := sync.WaitGroup{}
	errs := make(chan error)

	for _, inst := range instances[1:] {
		wg.Add(1)
		go func(inst Instance) {
			defer wg.Done()
			outch, err := inst.Exchange.GetBlocks(ctx, blkeys)
			if err != nil {
				errs <- err
			}
			for _ = range outch {
			}
		}(inst)
	}

	go func() {
		wg.Wait()
		close(errs)
	}()

	for err := range errs {
		if err != nil {
			t.Fatal(err)
		}
	}

	t.Log("Verify!")

	for _, inst := range instances {
		for _, b := range blocks {
			if _, err := inst.Blockstore().Get(b.Key()); err != nil {
				t.Fatal(err)
			}
		}
	}
}