package fs2

import (
	"io/ioutil"
	"os"
	"path/filepath"
	"testing"
)

func TestGetMemoryLimit(t *testing.T) {
	tmpCgroupDir, err := ioutil.TempDir("/tmp", "cgroup-")
	if err != nil {
		t.Fatal("Cannot create temporary file", err)
	}
	defer os.RemoveAll(tmpCgroupDir)

	tmpMemLimitFile := filepath.Join(tmpCgroupDir, "memory.max")
	DefaultMemLimit := float64(3 * 1024 * 1024 * 1024)

	type memTest struct {
		limitSet string
		limitGet float64
	}
	memTests := []memTest{
		{limitSet: "max", limitGet: DefaultMemLimit},
		{limitSet: "1024000000", limitGet: float64(1024000000)},
		{limitSet: "0", limitGet: DefaultMemLimit},
	}
	for i, test := range memTests {
		err = ioutil.WriteFile(tmpMemLimitFile, []byte(test.limitSet), 0)
		if err != nil {
			t.Fatal(i, "Failed to write to temporary file", err)
		}

		memLimit := GetMemoryLimit(tmpCgroupDir, DefaultMemLimit)
		if memLimit != test.limitGet {
			t.Fatalf("%d memLimit(%f) != expected(%f)", i, memLimit, test.limitGet)
		}
	}
}

func TestGetMemoryUsage(t *testing.T) {
	usage, workingSet, err := GetMemoryUsage("../testdata/cg2")
	if err != nil {
		t.Error("err:", err)
		return
	}
	if usage != 102400001 {
		t.Errorf("unexpected usage %d, should be %d", usage, 102400000)
		return
	}
	if workingSet != 100000001 {
		t.Errorf("unexpected usage %d, should be %d", workingSet, 100000000)
		return
	}
}

func TestGetKernelMemoryUsage(t *testing.T) {
	_, err := GetKernelMemoryUsage("../testdata/cg2")
	if err == nil {
		t.Error("err should not be nil")
		return
	}
}

func TestGetKernelMemorySlabInfo(t *testing.T) {
	_, err := GetKernelMemorySlabInfo("../testdata/cg2")
	if err == nil {
		t.Error("err should not be nil")
		return
	}
}