//go:build mxl_integration

package mxlfabrics_test

import (
	"os"
	"testing"

	"github.com/qvest-digital/go-mxl/fabrics"
	"github.com/qvest-digital/go-mxl/mxl"
)

func requireSHMInterface(
	t *testing.T,
	instance *fabrics.Instance,
) fabrics.InterfaceConfig {
	t.Helper()

	interfaces, err := instance.Interfaces(&fabrics.InterfaceConfig{
		Provider: fabrics.ProviderSHM,
	})
	if err != nil {
		t.Fatalf("enumerate SHM interfaces: %v", err)
	}

	for _, iface := range interfaces {
		if iface.Provider != fabrics.ProviderSHM {
			continue
		}
		if iface.Caps.Flags&fabrics.InterfaceCapRemoteWrite == 0 {
			continue
		}

		// Allow libfabric to assign a unique local SHM endpoint during
		// Target.Setup or Initiator.Setup. The enumerated service is
		// descriptive and should not be reused by both endpoints.
		iface.Address.Service = ""
		return iface
	}

	t.Fatal("no remote-write-capable SHM Fabrics interface found")
	return fabrics.InterfaceConfig{}
}

func TestInterfacesIncludesSHM(t *testing.T) {
	if _, err := os.Stat("/dev/shm"); err != nil {
		t.Skipf("/dev/shm is unavailable: %v", err)
	}

	domain, err := os.MkdirTemp("/dev/shm", "mxl-player-fabrics-*")
	if err != nil {
		t.Fatalf("create temporary MXL domain: %v", err)
	}
	t.Cleanup(func() {
		if err := os.RemoveAll(domain); err != nil {
			t.Errorf("remove temporary MXL domain: %v", err)
		}
	})

	instance, err := mxl.NewInstance(domain, "")
	if err != nil {
		t.Fatalf("create MXL instance: %v", err)
	}
	t.Cleanup(func() {
		if err := instance.Close(); err != nil {
			t.Errorf("close MXL instance: %v", err)
		}
	})

	fabricInstance, err := fabrics.NewInstance(instance)
	if err != nil {
		t.Fatalf("create Fabrics instance: %v", err)
	}
	t.Cleanup(func() {
		if err := fabricInstance.Close(); err != nil {
			t.Errorf("close Fabrics instance: %v", err)
		}
	})

	iface := requireSHMInterface(t, fabricInstance)

	t.Logf(
		"SHM interface: node=%q flags=%#x max-message-size=%d attr=%q",
		iface.Address.Node,
		iface.Caps.Flags,
		iface.Caps.MaxMessageSize,
		iface.Attr,
	)
}