// +build linux

package mem

import (
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestVirtualMemoryEx(t *testing.T) {
	v, err := VirtualMemoryEx()
	if err != nil {
		t.Error(err)
	}

	t.Log(v)
}

var virtualMemoryTests = []struct {
	mockedRootFS string
	stat         *VirtualMemoryStat
}{
	{"intelcorei5", &VirtualMemoryStat{
		Total:          16502300672,
		Available:      11495358464,
		Used:           3437277184,
		UsedPercent:    20.82907863769651,
		Free:           8783491072,
		Active:         4347392000,
		Inactive:       2938834944,
		Wired:          0,
		Laundry:        0,
		Buffers:        212496384,
		Cached:         4069036032,
		Writeback:      0,
		Dirty:          176128,
		WritebackTmp:   0,
		Shared:         1222402048,
		Slab:           253771776,
		SReclaimable:   186470400,
		SUnreclaim:     67301376,
		PageTables:     65241088,
		SwapCached:     0,
		CommitLimit:    16509730816,
		CommittedAS:    12360818688,
		HighTotal:      0,
		HighFree:       0,
		LowTotal:       0,
		LowFree:        0,
		SwapTotal:      8258580480,
		SwapFree:       8258580480,
		Mapped:         1172627456,
		VMallocTotal:   35184372087808,
		VMallocUsed:    0,
		VMallocChunk:   0,
		HugePagesTotal: 0,
		HugePagesFree:  0,
		HugePageSize:   2097152},
	},
	{"issue1002", &VirtualMemoryStat{
		Total:          260579328,
		Available:      215199744,
		Used:           34328576,
		UsedPercent:    13.173944481121694,
		Free:           124506112,
		Active:         108785664,
		Inactive:       8581120,
		Wired:          0,
		Laundry:        0,
		Buffers:        4915200,
		Cached:         96829440,
		Writeback:      0,
		Dirty:          0,
		WritebackTmp:   0,
		Shared:         0,
		Slab:           9293824,
		SReclaimable:   2764800,
		SUnreclaim:     6529024,
		PageTables:     405504,
		SwapCached:     0,
		CommitLimit:    130289664,
		CommittedAS:    25567232,
		HighTotal:      134217728,
		HighFree:       67784704,
		LowTotal:       126361600,
		LowFree:        56721408,
		SwapTotal:      0,
		SwapFree:       0,
		Mapped:         38793216,
		VMallocTotal:   1996488704,
		VMallocUsed:    0,
		VMallocChunk:   0,
		HugePagesTotal: 0,
		HugePagesFree:  0,
		HugePageSize:   0},
	},
}

func TestVirtualMemoryLinux(t *testing.T) {
	origProc := os.Getenv("HOST_PROC")
	defer os.Setenv("HOST_PROC", origProc)

	for _, tt := range virtualMemoryTests {
		t.Run(tt.mockedRootFS, func(t *testing.T) {
			os.Setenv("HOST_PROC", filepath.Join("testdata/linux/virtualmemory/", tt.mockedRootFS, "proc"))

			stat, err := VirtualMemory()
			skipIfNotImplementedErr(t, err)
			if err != nil {
				t.Errorf("error %v", err)
			}
			if !reflect.DeepEqual(stat, tt.stat) {
				t.Errorf("got: %+v\nwant: %+v", stat, tt.stat)
			}
		})
	}
}

const validFile = `Filename				Type		Size		Used		Priority
/dev/dm-2                               partition	67022844	490788		-2
/swapfile                               file		2		1		-3
`

const invalidFile = `INVALID				Type		Size		Used		Priority
/dev/dm-2                               partition	67022844	490788		-2
/swapfile                               file		1048572		0		-3
`

func TestParseSwapsFile_ValidFile(t *testing.T) {
	assert := assert.New(t)
	stats, err := parseSwapsFile(strings.NewReader(validFile))
	assert.NoError(err)

	assert.Equal(*stats[0], SwapDevice{
		Name:      "/dev/dm-2",
		UsedBytes: 502566912,
		FreeBytes: 68128825344,
	})

	assert.Equal(*stats[1], SwapDevice{
		Name:      "/swapfile",
		UsedBytes: 1024,
		FreeBytes: 1024,
	})
}

func TestParseSwapsFile_InvalidFile(t *testing.T) {
	_, err := parseSwapsFile(strings.NewReader(invalidFile))
	assert.Error(t, err)
}

func TestParseSwapsFile_EmptyFile(t *testing.T) {
	_, err := parseSwapsFile(strings.NewReader(""))
	assert.Error(t, err)
}
