package notify

import (
	"context"
	"errors"
	"math"
	"net"
	"testing"
	"time"

	"b612.me/stario"
)

func TestClientConnCurrentTransportConnStreamSnapshot(t *testing.T) {
	server := NewServer().(*ServerCommon)
	left, right := net.Pipe()
	defer left.Close()
	defer right.Close()

	logical := server.bootstrapAcceptedLogical("transport-stream", nil, left)
	if logical == nil {
		t.Fatal("bootstrapAcceptedLogical should return logical")
	}

	transport := logical.CurrentTransportConn()
	if transport == nil {
		t.Fatal("CurrentTransportConn should expose active stream transport")
	}
	if transport.LogicalConn() != logical {
		t.Fatal("LogicalConn mismatch")
	}
	if !transport.Attached() {
		t.Fatal("Attached mismatch: got false want true")
	}
	if !transport.HasRuntimeConn() {
		t.Fatal("HasRuntimeConn mismatch: got false want true")
	}
	if !transport.UsesStreamTransport() {
		t.Fatal("UsesStreamTransport mismatch: got false want true")
	}
	if !transport.IsCurrent() {
		t.Fatal("IsCurrent mismatch: got false want true")
	}
	snapshot, err := GetTransportConnRuntimeSnapshot(transport)
	if err != nil {
		t.Fatalf("GetTransportConnRuntimeSnapshot failed: %v", err)
	}
	if got, want := snapshot.ClientID, logical.ClientID; got != want {
		t.Fatalf("ClientID mismatch: got %q want %q", got, want)
	}
	if !snapshot.Attached || !snapshot.HasRuntimeConn || !snapshot.Current {
		t.Fatalf("unexpected transport snapshot: %+v", snapshot)
	}
	if got, want := snapshot.BindingOwner, "server-transport"; got != want {
		t.Fatalf("BindingOwner mismatch: got %q want %q", got, want)
	}
	if !snapshot.BindingCurrent || !snapshot.LogicalAlive {
		t.Fatalf("binding state mismatch: %+v", snapshot)
	}
}

func TestClientConnCurrentTransportConnPacketSnapshot(t *testing.T) {
	server := NewServer().(*ServerCommon)
	stopCtx, stopFn := context.WithCancel(context.Background())
	defer stopFn()
	udpListener, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.ParseIP("127.0.0.1"), Port: 0})
	if err != nil {
		t.Fatalf("ListenUDP failed: %v", err)
	}
	defer udpListener.Close()
	server.setServerSessionRuntime(&serverSessionRuntime{
		stopCtx:     stopCtx,
		stopFn:      stopFn,
		udpListener: udpListener,
	})

	addr, err := net.ResolveUDPAddr("udp", "127.0.0.1:34567")
	if err != nil {
		t.Fatalf("ResolveUDPAddr failed: %v", err)
	}
	logical := server.bootstrapAcceptedLogical("transport-packet", addr, nil)
	if logical == nil {
		t.Fatal("bootstrapAcceptedLogical should return packet logical")
	}

	transport := logical.CurrentTransportConn()
	if transport == nil {
		t.Fatal("CurrentTransportConn should expose packet transport route")
	}
	if got, want := transport.RemoteAddr().String(), addr.String(); got != want {
		t.Fatalf("RemoteAddr mismatch: got %q want %q", got, want)
	}
	if !transport.Attached() {
		t.Fatal("Attached mismatch: got false want true")
	}
	if transport.HasRuntimeConn() {
		t.Fatal("packet transport should not expose runtime conn")
	}
	if transport.TransportGeneration() != 0 {
		t.Fatalf("packet transport generation mismatch: got %d want 0", transport.TransportGeneration())
	}
}

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

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

	firstLeft, firstRight := net.Pipe()
	defer firstRight.Close()
	logical, _, _ := newRegisteredServerLogicalForTest(t, server, "transport-send-stale", firstLeft, runtimeCtx, runtimeCancel)
	logical.applyClientConnAttachmentProfile(0, 100*time.Millisecond, server.defaultMsgEn, server.defaultMsgDe, server.handshakeRsaKey, server.SecretKey)
	firstTransport := logical.CurrentTransportConn()
	if firstTransport == nil {
		t.Fatal("first transport snapshot should exist")
	}

	secondLeft, secondRight := net.Pipe()
	defer secondRight.Close()
	if err := logical.attachClientConnSessionTransport(secondLeft); err != nil {
		t.Fatalf("attachClientConnSessionTransport failed: %v", err)
	}
	secondTransport := logical.CurrentTransportConn()
	if secondTransport == nil {
		t.Fatal("second transport snapshot should exist after reattach")
	}
	if firstTransport.IsCurrent() {
		t.Fatal("first transport should become stale after reattach")
	}

	if err := firstTransport.Send("stale", MsgVal("payload")); !errors.Is(err, errTransportDetached) {
		t.Fatalf("stale transport send error = %v, want errors.Is(..., %v)", err, errTransportDetached)
	}

	recvCh := make(chan []byte, 1)
	errCh := make(chan error, 1)
	go func() {
		_ = secondRight.SetReadDeadline(time.Now().Add(time.Second))
		reader := stario.NewFrameReader(secondRight, nil)
		payload, err := reader.Next()
		if err != nil {
			errCh <- err
			return
		}
		recvCh <- payload
	}()

	if err := secondTransport.Send("fresh", MsgVal("payload")); err != nil {
		t.Fatalf("fresh transport send failed: %v", err)
	}

	select {
	case err := <-errCh:
		t.Fatalf("fresh transport read failed: %v", err)
	case got := <-recvCh:
		if len(got) == 0 {
			t.Fatal("fresh transport should produce framed payload")
		}
	case <-time.After(time.Second):
		t.Fatal("fresh transport send timed out")
	}
}

func TestTransportConnRuntimeSnapshotIncludesDetachDiagnostics(t *testing.T) {
	server := NewServer().(*ServerCommon)
	left, right := net.Pipe()
	defer right.Close()

	logical := server.bootstrapAcceptedLogical("transport-detach", nil, left)
	if logical == nil {
		t.Fatal("bootstrapAcceptedLogical should return logical")
	}
	transport := logical.CurrentTransportConn()
	if transport == nil {
		t.Fatal("CurrentTransportConn should return active transport")
	}

	server.detachLogicalSessionTransport(logical, "read error", errors.New("boom"))

	snapshot, err := GetTransportConnRuntimeSnapshot(transport)
	if err != nil {
		t.Fatalf("GetTransportConnRuntimeSnapshot failed: %v", err)
	}
	if snapshot.Current {
		t.Fatalf("snapshot Current should be false after detach: %+v", snapshot)
	}
	if snapshot.BindingCurrent {
		t.Fatalf("snapshot BindingCurrent should be false after detach: %+v", snapshot)
	}
	if got, want := snapshot.LogicalReason, ""; got != want {
		t.Fatalf("snapshot LogicalReason = %q, want %q", got, want)
	}
	if got, want := snapshot.TransportDetachReason, "read error"; got != want {
		t.Fatalf("snapshot TransportDetachReason = %q, want %q", got, want)
	}
	if got, want := snapshot.TransportDetachKind, clientConnTransportDetachKindReadError; got != want {
		t.Fatalf("snapshot TransportDetachKind = %q, want %q", got, want)
	}
	if got, want := snapshot.TransportDetachError, "boom"; got != want {
		t.Fatalf("snapshot TransportDetachError = %q, want %q", got, want)
	}
}