package platform

import (
	"os"
	"os/exec"
	"path/filepath"
	"testing"
)

func TestExportFileToTargetUnmountsExistingMountpoint(t *testing.T) {
	t.Parallel()

	tmp := t.TempDir()
	src := filepath.Join(tmp, "bundle.tar.gz")
	mountpoint := filepath.Join(tmp, "mnt")
	if err := os.MkdirAll(mountpoint, 0755); err != nil {
		t.Fatalf("mkdir mountpoint: %v", err)
	}
	if err := os.WriteFile(src, []byte("bundle"), 0644); err != nil {
		t.Fatalf("write src: %v", err)
	}

	var calls [][]string
	oldExec := exportExecCommand
	exportExecCommand = func(name string, args ...string) *exec.Cmd {
		calls = append(calls, append([]string{name}, args...))
		return exec.Command("sh", "-c", "exit 0")
	}
	t.Cleanup(func() { exportExecCommand = oldExec })

	s := &System{}
	dst, err := s.ExportFileToTarget(src, RemovableTarget{
		Device:     "/dev/sdb1",
		Mountpoint: mountpoint,
	})
	if err != nil {
		t.Fatalf("ExportFileToTarget error: %v", err)
	}
	if got, want := dst, filepath.Join(mountpoint, "bundle.tar.gz"); got != want {
		t.Fatalf("dst=%q want %q", got, want)
	}
	if _, err := os.Stat(filepath.Join(mountpoint, "bundle.tar.gz")); err != nil {
		t.Fatalf("exported file missing: %v", err)
	}

	foundUmount := false
	for _, call := range calls {
		if len(call) == 2 && call[0] == "umount" && call[1] == mountpoint {
			foundUmount = true
			break
		}
	}
	if !foundUmount {
		t.Fatalf("expected umount %q call, got %#v", mountpoint, calls)
	}
}