package fs

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

const (
	cgroupFile  = "cgroup.file"
	floatValue  = 2048.0
	floatString = "2048"
)

func TestGetCgroupParamsFloat64(t *testing.T) {
	// Setup tempdir.
	tempDir, err := ioutil.TempDir("", "cgroup_utils_test")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tempDir)
	tempFile := filepath.Join(tempDir, cgroupFile)

	// Success.
	err = ioutil.WriteFile(tempFile, []byte(floatString), 0755)
	if err != nil {
		t.Fatal(err)
	}
	value, err := getCgroupParamFloat64(tempDir, cgroupFile)
	if err != nil {
		t.Fatal(err)
	} else if value != floatValue {
		t.Fatalf("Expected %f to equal %f", value, floatValue)
	}

	// Success with new line.
	err = ioutil.WriteFile(tempFile, []byte(floatString+"\n"), 0755)
	if err != nil {
		t.Fatal(err)
	}
	value, err = getCgroupParamFloat64(tempDir, cgroupFile)
	if err != nil {
		t.Fatal(err)
	} else if value != floatValue {
		t.Fatalf("Expected %f to equal %f", value, floatValue)
	}

	// Not a float.
	err = ioutil.WriteFile(tempFile, []byte("not-a-float"), 0755)
	if err != nil {
		t.Fatal(err)
	}
	_, err = getCgroupParamFloat64(tempDir, cgroupFile)
	if err == nil {
		t.Fatal("Expecting error, got none")
	}

	// Unknown file.
	err = os.Remove(tempFile)
	if err != nil {
		t.Fatal(err)
	}
	_, err = getCgroupParamFloat64(tempDir, cgroupFile)
	if err == nil {
		t.Fatal("Expecting error, got none")
	}
}
