//go:build linux

package console

import (
	"errors"
	"os"
	"syscall"
	"testing"

	"github.com/carlosframework/platform/internal/hostops"
)

func init() {
	// The shared test TMPDIR is tmpfs, which production must refuse because
	// its receipts do not survive boot. Model only its filesystem UUID; keep
	// the real file descriptor, inode and DB UUID for all SQL/fence tests.
	sqlFilesystemUUID = func(fd uintptr) ([16]byte, error) {
		var fs syscall.Statfs_t
		if err := syscall.Fstatfs(int(fd), &fs); err != nil {
			return [16]byte{}, err
		}
		if fs.Type == 0x01021994 {
			return [16]byte{0x54, 0x45, 0x53, 0x54}, nil
		}
		return readSQLFilesystemUUID(fd)
	}
}

func TestPlan9SQLIdentitySurvivesDeviceRenumber(t *testing.T) {
	uuid := [16]byte{1, 2, 3, 4}
	st := syscall.Stat_t{Dev: 17, Ino: 99}
	before, err := sqlPhysicalIdentityFrom([]byte("machine"), uuid, st)
	if err != nil {
		t.Fatal(err)
	}
	st.Dev = 4097
	after, err := sqlPhysicalIdentityFrom([]byte("machine"), uuid, st)
	if err != nil || before != after {
		t.Fatalf("device renumber changed identity: %q %q %v", before, after, err)
	}
	st.Ino++
	copied, err := sqlPhysicalIdentityFrom([]byte("machine"), uuid, st)
	if err != nil || copied == before {
		t.Fatal("copy on the same filesystem claimed original inode")
	}
	st.Ino--
	uuid[0]++
	copied, err = sqlPhysicalIdentityFrom([]byte("machine"), uuid, st)
	if err != nil || copied == before {
		t.Fatal("different filesystem claimed original inode")
	}
	if _, err = sqlPhysicalIdentityFrom([]byte("machine"), [16]byte{}, st); err == nil {
		t.Fatal("missing authoritative filesystem UUID accepted")
	}
}

func TestPlan9SQLIdentityUnsupportedFilesystemRefuses(t *testing.T) {
	f, err := os.Open("/proc/self/status")
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()
	if _, err = readSQLFilesystemUUID(f.Fd()); !errors.Is(err, hostops.ErrContract) {
		t.Fatalf("proc filesystem accepted: %v", err)
	}
}

func TestPlan9Fix1SQLFilesystemProbeAcceptsBtrfs(t *testing.T) {
	for _, tc := range []struct {
		name string
		typ  int64
		want bool
	}{{"ext4", 0xef53, true}, {"xfs", 0x58465342, true}, {"btrfs", 0x9123683e, true}, {"tmpfs", 0x01021994, false}, {"proc", 0x9fa0, false}} {
		if got := sqlFilesystemSupported(tc.typ); got != tc.want {
			t.Errorf("%s: supported=%v, want %v", tc.name, got, tc.want)
		}
	}
}