package notify

import (
	"b612.me/stario"
	"context"
	"errors"
	"math"
	"net"
	"testing"
	"time"
)

func readServerEnvelopeFromConnWithProfile(t *testing.T, server *ServerCommon, profile transportProtectionProfile, conn net.Conn, timeout time.Duration) Envelope {
	t.Helper()

	queue := stario.NewQueue()
	deadline := time.Now().Add(timeout)
	buf := make([]byte, 4096)
	for time.Now().Before(deadline) {
		if err := conn.SetReadDeadline(deadline); err != nil {
			t.Fatalf("SetReadDeadline failed: %v", err)
		}
		n, err := conn.Read(buf)
		if n > 0 {
			if parseErr := queue.ParseMessage(buf[:n], "server-inbound-profile"); parseErr != nil {
				t.Fatalf("ParseMessage failed: %v", parseErr)
			}
			select {
			case msg := <-queue.RestoreChan():
				plain, decErr := decryptTransportPayloadCodec(profile.mode, profile.runtime, profile.msgDe, profile.secretKey, msg.Msg)
				if decErr != nil {
					t.Fatalf("decryptTransportPayloadCodec failed: %v", decErr)
				}
				env, decErr := server.decodeEnvelopePlain(plain)
				if decErr != nil {
					t.Fatalf("decodeEnvelopePlain failed: %v", decErr)
				}
				return env
			default:
			}
		}
		if err == nil {
			continue
		}
		if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
			break
		}
		t.Fatalf("conn Read failed: %v", err)
	}
	t.Fatal("timed out waiting for server envelope")
	return Envelope{}
}

func TestMessageReplyUsesInboundConnForStaleTransport(t *testing.T) {
	server := NewServer().(*ServerCommon)
	UseLegacySecurityServer(server)

	stopCtx, stopFn := context.WithCancel(context.Background())
	defer stopFn()
	server.setServerSessionRuntime(&serverSessionRuntime{
		stopCtx: stopCtx,
		stopFn:  stopFn,
		queue:   stario.NewQueueCtx(stopCtx, 4, math.MaxUint32),
	})
	server.markSessionStarted()
	defer server.markSessionStopped("test done", nil)

	firstLeft, firstRight := net.Pipe()
	defer firstLeft.Close()
	defer firstRight.Close()

	logical, _, _ := newRegisteredServerLogicalForTest(t, server, "reply-inbound-stale", firstLeft, stopCtx, stopFn)
	client := clientConnFromLogical(logical)
	client.applyClientConnAttachmentProfile(0, 0, server.defaultMsgEn, server.defaultMsgDe, server.handshakeRsaKey, server.SecretKey)

	staleTransport := logical.transportConnSnapshotForInbound(firstLeft, nil, logical.transportGenerationSnapshot()+1, true)
	if staleTransport == nil {
		t.Fatal("stale transport snapshot should exist")
	}
	if staleTransport.IsCurrent() {
		t.Fatal("stale transport should not be current for mismatched generation")
	}

	message := Message{
		NetType:       NET_SERVER,
		LogicalConn:   logical,
		TransportConn: staleTransport,
		TransferMsg: TransferMsg{
			ID:   11,
			Key:  "reply-inbound",
			Type: MSG_SYNC_ASK,
		},
		Time:        time.Now(),
		inboundConn: firstLeft,
	}

	done := make(chan error, 1)
	go func() {
		done <- message.Reply(MsgVal("ok"))
	}()

	env := readServerEnvelopeFromConn(t, server, logical, firstRight, time.Second)
	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("Message.Reply failed: %v", err)
		}
	case <-time.After(time.Second):
		t.Fatal("timed out waiting for Message.Reply to finish")
	}

	transfer, err := unwrapTransferMsgEnvelope(env, server.sequenceDe)
	if err != nil {
		t.Fatalf("unwrapTransferMsgEnvelope failed: %v", err)
	}
	if transfer.Type != MSG_SYNC_REPLY {
		t.Fatalf("reply type = %v, want %v", transfer.Type, MSG_SYNC_REPLY)
	}
	if transfer.ID != 11 {
		t.Fatalf("reply id = %d, want %d", transfer.ID, 11)
	}
	if transfer.Key != "reply-inbound" {
		t.Fatalf("reply key = %q, want %q", transfer.Key, "reply-inbound")
	}
	if string(transfer.Value) != "ok" {
		t.Fatalf("reply value = %q, want %q", string(transfer.Value), "ok")
	}
}

func TestMessageReplyUsesInboundProtectionSnapshotAfterLogicalSwitch(t *testing.T) {
	secret := []byte("correct horse battery staple")
	alternate, err := deriveModernPSKProtectionProfile([]byte("notify-reply-snapshot-alternate"), testModernPSKOptions(), ProtectionManaged)
	if err != nil {
		t.Fatalf("deriveModernPSKProtectionProfile failed: %v", err)
	}
	handlerErr := make(chan error, 1)
	server := newRunningPeerAttachServerForTest(t, func(server *ServerCommon) {
		if err := UseModernPSKServer(server, secret, testModernPSKOptions()); err != nil {
			t.Fatalf("UseModernPSKServer failed: %v", err)
		}
		server.SetLink("reply-snapshot", func(msg *Message) {
			if msg == nil || msg.LogicalConn == nil {
				select {
				case handlerErr <- errors.New("reply-snapshot logical is nil"):
				default:
				}
				return
			}
			msg.LogicalConn.applyTransportProtectionProfile(alternate)
			if err := msg.Reply([]byte("ack")); err != nil {
				select {
				case handlerErr <- err:
				default:
				}
			}
		})
	})
	client := NewClient().(*ClientCommon)
	if err := UseModernPSKClient(client, secret, testModernPSKOptions()); err != nil {
		t.Fatalf("UseModernPSKClient failed: %v", err)
	}

	left, right := net.Pipe()
	defer right.Close()
	bootstrapPeerAttachConnForTest(t, server, right)
	if err := client.ConnectByConn(left); err != nil {
		t.Fatalf("ConnectByConn failed: %v", err)
	}
	defer func() {
		client.setByeFromServer(true)
		_ = client.Stop()
	}()

	reply, err := client.SendWait("reply-snapshot", []byte("ping"), time.Second)
	if err != nil {
		t.Fatalf("SendWait failed: %v", err)
	}
	if got, want := string(reply.Value), "ack"; got != want {
		t.Fatalf("reply value = %q, want %q", got, want)
	}
	select {
	case err := <-handlerErr:
		t.Fatalf("reply-snapshot handler failed: %v", err)
	default:
	}
}

func TestServerHandleReceivedSignalReliabilityUsesInboundConnForStaleTransport(t *testing.T) {
	server := NewServer().(*ServerCommon)
	UseLegacySecurityServer(server)
	if err := UseSignalReliabilityServer(server, &SignalReliabilityOptions{Enabled: true}); err != nil {
		t.Fatalf("UseSignalReliabilityServer failed: %v", err)
	}

	stopCtx, stopFn := context.WithCancel(context.Background())
	defer stopFn()
	server.setServerSessionRuntime(&serverSessionRuntime{
		stopCtx: stopCtx,
		stopFn:  stopFn,
		queue:   stario.NewQueueCtx(stopCtx, 4, math.MaxUint32),
	})

	firstLeft, firstRight := net.Pipe()
	defer firstLeft.Close()
	defer firstRight.Close()

	logical, _, _ := newRegisteredServerLogicalForTest(t, server, "signal-ack-inbound-stale", firstLeft, stopCtx, stopFn)
	client := clientConnFromLogical(logical)
	client.applyClientConnAttachmentProfile(0, 0, server.defaultMsgEn, server.defaultMsgDe, server.handshakeRsaKey, server.SecretKey)

	staleTransport := logical.transportConnSnapshotForInbound(firstLeft, nil, logical.transportGenerationSnapshot()+1, true)
	if staleTransport == nil {
		t.Fatal("stale transport snapshot should exist")
	}
	if staleTransport.IsCurrent() {
		t.Fatal("stale transport should not be current for mismatched generation")
	}

	done := make(chan bool, 1)
	go func() {
		done <- server.handleReceivedSignalReliabilityTransport(logical, staleTransport, firstLeft, TransferMsg{
			ID:   22,
			Key:  "signal-reliable",
			Type: MSG_ASYNC,
		})
	}()

	env := readServerEnvelopeFromConn(t, server, logical, firstRight, time.Second)
	select {
	case duplicate := <-done:
		if duplicate {
			t.Fatal("first reliable signal receive should not be duplicate")
		}
	case <-time.After(time.Second):
		t.Fatal("timed out waiting for signal reliability handler to finish")
	}

	if env.Kind != EnvelopeSignalAck {
		t.Fatalf("ack envelope kind = %v, want %v", env.Kind, EnvelopeSignalAck)
	}
	if env.ID != 22 {
		t.Fatalf("ack signal id = %d, want %d", env.ID, 22)
	}
}

func TestServerDispatchFileEnvelopeUsesInboundConnForStaleTransportAck(t *testing.T) {
	server := NewServer().(*ServerCommon)
	UseLegacySecurityServer(server)

	stopCtx, stopFn := context.WithCancel(context.Background())
	defer stopFn()
	server.setServerSessionRuntime(&serverSessionRuntime{
		stopCtx: stopCtx,
		stopFn:  stopFn,
		queue:   stario.NewQueueCtx(stopCtx, 4, math.MaxUint32),
	})

	firstLeft, firstRight := net.Pipe()
	defer firstLeft.Close()
	defer firstRight.Close()

	logical, _, _ := newRegisteredServerLogicalForTest(t, server, "file-ack-inbound-stale", firstLeft, stopCtx, stopFn)
	client := clientConnFromLogical(logical)
	client.applyClientConnAttachmentProfile(0, 0, server.defaultMsgEn, server.defaultMsgDe, server.handshakeRsaKey, server.SecretKey)

	staleTransport := logical.transportConnSnapshotForInbound(firstLeft, nil, logical.transportGenerationSnapshot()+1, true)
	if staleTransport == nil {
		t.Fatal("stale transport snapshot should exist")
	}
	if staleTransport.IsCurrent() {
		t.Fatal("stale transport should not be current for mismatched generation")
	}

	done := make(chan struct{})
	go func() {
		server.dispatchFileEnvelope(logical, staleTransport, firstLeft, newFileMetaEnvelope("file-1", "demo.bin", 4, "", 0, 0), time.Now())
		close(done)
	}()

	env := readServerEnvelopeFromConn(t, server, logical, firstRight, time.Second)
	select {
	case <-done:
	case <-time.After(time.Second):
		t.Fatal("timed out waiting for file dispatch to finish")
	}

	if env.Kind != EnvelopeAck {
		t.Fatalf("file ack envelope kind = %v, want %v", env.Kind, EnvelopeAck)
	}
	if env.File.FileID != "file-1" {
		t.Fatalf("file ack file id = %q, want %q", env.File.FileID, "file-1")
	}
	if env.File.Stage != "meta" {
		t.Fatalf("file ack stage = %q, want %q", env.File.Stage, "meta")
	}
	if env.File.Offset != 0 {
		t.Fatalf("file ack offset = %d, want %d", env.File.Offset, 0)
	}
}