// Misc returnes miscellaneous host-wide statistics.
// Note: the name should be changed near future.
func Misc() (*MiscStat, error) {
	filename := common.HostProc("stat")
	out, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, err
	}

	ret := &MiscStat{}
	lines := strings.Split(string(out), "\n")
	for _, line := range lines {
		fields := strings.Fields(line)
		if len(fields) != 2 {
			continue
		}
		v, err := strconv.ParseInt(fields[1], 10, 64)
		if err != nil {
			continue
		}
		switch fields[0] {
		case "procs_running":
			ret.ProcsRunning = int(v)
		case "procs_blocked":
			ret.ProcsBlocked = int(v)
		case "ctxt":
			ret.Ctxt = int(v)
		default:
			continue
		}

	}

	return ret, nil
}

// Get num_fds from /proc/(pid)/fd
func (p *Process) fillFromfd() (int32, []*OpenFilesStat, error) {
	pid := p.Pid
	statPath := common.HostProc(strconv.Itoa(int(pid)), "fd")
	d, err := os.Open(statPath)
	if err != nil {
		return 0, nil, err
	}
	defer d.Close()
	fnames, err := d.Readdirnames(-1)
	numFDs := int32(len(fnames))

	var openfiles []*OpenFilesStat
	for _, fd := range fnames {
		fpath := filepath.Join(statPath, fd)
		filepath, err := os.Readlink(fpath)
		if err != nil {
			continue
		}
		t, err := strconv.ParseUint(fd, 10, 64)
		if err != nil {
			return numFDs, openfiles, err
		}
		o := &OpenFilesStat{
			Path: filepath,
			Fd:   t,
		}
		openfiles = append(openfiles, o)
	}

	return numFDs, openfiles, nil
}

func LoadAvg() (*LoadAvgStat, error) {
	filename := common.HostProc("loadavg")
	line, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, err
	}

	values := strings.Fields(string(line))

	load1, err := strconv.ParseFloat(values[0], 64)
	if err != nil {
		return nil, err
	}
	load5, err := strconv.ParseFloat(values[1], 64)
	if err != nil {
		return nil, err
	}
	load15, err := strconv.ParseFloat(values[2], 64)
	if err != nil {
		return nil, err
	}

	ret := &LoadAvgStat{
		Load1:  load1,
		Load5:  load5,
		Load15: load15,
	}

	return ret, nil
}

func Times(percpu bool) ([]TimesStat, error) {
	filename := common.HostProc("stat")
	var lines = []string{}
	if percpu {
		var startIdx uint = 1
		for {
			linen, _ := common.ReadLinesOffsetN(filename, startIdx, 1)
			line := linen[0]
			if !strings.HasPrefix(line, "cpu") {
				break
			}
			lines = append(lines, line)
			startIdx++
		}
	} else {
		lines, _ = common.ReadLinesOffsetN(filename, 0, 1)
	}

	ret := make([]TimesStat, 0, len(lines))

	for _, line := range lines {
		ct, err := parseStatLine(line)
		if err != nil {
			continue
		}
		ret = append(ret, *ct)

	}
	return ret, nil
}

// Get status from /proc/(pid)/status
func (p *process) fillFromStatus() error {
	pid := p.Pid
	statPath := common.HostProc(strconv.Itoa(int(pid)), "status")
	contents, err := ioutil.ReadFile(statPath)
	if err != nil {
		return err
	}
	lines := strings.Split(string(contents), "\n")
	for _, line := range lines {
		tabParts := strings.SplitN(line, "\t", 2)
		if len(tabParts) < 2 {
			continue
		}
		value := tabParts[1]
		switch strings.TrimRight(tabParts[0], ":") {
		case "Uid":
			p.uids = make([]int32, 0, 4)
			for _, i := range strings.Split(value, "\t") {
				v, err := strconv.ParseInt(i, 10, 32)
				if err != nil {
					return err
				}
				p.uids = append(p.uids, int32(v))
			}
		}
	}
	return nil
}

func IOCounters() (map[string]IOCountersStat, error) {
	filename := common.HostProc("diskstats")
	lines, err := common.ReadLines(filename)
	if err != nil {
		return nil, err
	}
	ret := make(map[string]IOCountersStat, 0)
	empty := IOCountersStat{}

	for _, line := range lines {
		fields := strings.Fields(line)
		name := fields[2]
		reads, err := strconv.ParseUint((fields[3]), 10, 64)
		if err != nil {
			return ret, err
		}
		rbytes, err := strconv.ParseUint((fields[5]), 10, 64)
		if err != nil {
			return ret, err
		}
		rtime, err := strconv.ParseUint((fields[6]), 10, 64)
		if err != nil {
			return ret, err
		}
		writes, err := strconv.ParseUint((fields[7]), 10, 64)
		if err != nil {
			return ret, err
		}
		wbytes, err := strconv.ParseUint((fields[9]), 10, 64)
		if err != nil {
			return ret, err
		}
		wtime, err := strconv.ParseUint((fields[10]), 10, 64)
		if err != nil {
			return ret, err
		}
		iotime, err := strconv.ParseUint((fields[12]), 10, 64)
		if err != nil {
			return ret, err
		}
		d := IOCountersStat{
			ReadBytes:  rbytes * SectorSize,
			WriteBytes: wbytes * SectorSize,
			ReadCount:  reads,
			WriteCount: writes,
			ReadTime:   rtime,
			WriteTime:  wtime,
			IoTime:     iotime,
		}
		if d == empty {
			continue
		}
		d.Name = name

		d.SerialNumber = GetDiskSerialNumber(name)
		ret[name] = d
	}
	return ret, nil
}

func (p *Process) fillFromStat() (string, int32, *cpu.TimesStat, int64, int32, error) {
	pid := p.Pid
	statPath := common.HostProc(strconv.Itoa(int(pid)), "stat")
	contents, err := ioutil.ReadFile(statPath)
	if err != nil {
		return "", 0, nil, 0, 0, err
	}
	fields := strings.Fields(string(contents))

	i := 1
	for !strings.HasSuffix(fields[i], ")") {
		i++
	}

	termmap, err := getTerminalMap()
	terminal := ""
	if err == nil {
		t, err := strconv.ParseUint(fields[i+5], 10, 64)
		if err != nil {
			return "", 0, nil, 0, 0, err
		}
		terminal = termmap[t]
	}

	ppid, err := strconv.ParseInt(fields[i+2], 10, 32)
	if err != nil {
		return "", 0, nil, 0, 0, err
	}
	utime, err := strconv.ParseFloat(fields[i+12], 64)
	if err != nil {
		return "", 0, nil, 0, 0, err
	}

	stime, err := strconv.ParseFloat(fields[i+13], 64)
	if err != nil {
		return "", 0, nil, 0, 0, err
	}

	cpuTimes := &cpu.TimesStat{
		CPU:    "cpu",
		User:   float64(utime / ClockTicks),
		System: float64(stime / ClockTicks),
	}

	bootTime, _ := host.BootTime()
	t, err := strconv.ParseUint(fields[i+20], 10, 64)
	if err != nil {
		return "", 0, nil, 0, 0, err
	}
	ctime := (t / uint64(ClockTicks)) + uint64(bootTime)
	createTime := int64(ctime * 1000)

	//	p.Nice = mustParseInt32(fields[18])
	// use syscall instead of parse Stat file
	snice, _ := syscall.Getpriority(PrioProcess, int(pid))
	nice := int32(snice) // FIXME: is this true?

	return terminal, int32(ppid), cpuTimes, createTime, nice, nil
}

// NewProcess creates a new Process instance, it only stores the pid and
// checks that the process exists. Other method on Process can be used
// to get more information about the process. An error will be returned
// if the process does not exist.
func NewProcess(pid int32) (*Process, error) {
	p := &Process{
		Pid: int32(pid),
	}
	file, err := os.Open(common.HostProc(strconv.Itoa(int(p.Pid))))
	defer file.Close()
	return p, err
}

// Get cwd from /proc/(pid)/cwd
func (p *Process) fillFromCwd() (string, error) {
	pid := p.Pid
	cwdPath := common.HostProc(strconv.Itoa(int(pid)), "cwd")
	cwd, err := os.Readlink(cwdPath)
	if err != nil {
		return "", err
	}
	return string(cwd), nil
}

// Get exe from /proc/(pid)/exe
func (p *Process) fillFromExe() (string, error) {
	pid := p.Pid
	exePath := common.HostProc(strconv.Itoa(int(pid)), "exe")
	exe, err := os.Readlink(exePath)
	if err != nil {
		return "", err
	}
	return string(exe), nil
}

func TestGetProcInodesAll(t *testing.T) {
	if os.Getenv("CIRCLECI") == "true" {
		t.Skip("Skip CI")
	}

	root := common.HostProc("")
	v, err := getProcInodesAll(root)
	assert.Nil(t, err)
	assert.NotEmpty(t, v)
}

// NetProtoCounters returns network statistics for the entire system
// If protocols is empty then all protocols are returned, otherwise
// just the protocols in the list are returned.
// Available protocols:
//   ip,icmp,icmpmsg,tcp,udp,udplite
func ProtoCounters(protocols []string) ([]ProtoCountersStat, error) {
	if len(protocols) == 0 {
		protocols = netProtocols
	}

	stats := make([]ProtoCountersStat, 0, len(protocols))
	protos := make(map[string]bool, len(protocols))
	for _, p := range protocols {
		protos[p] = true
	}

	filename := common.HostProc("net/snmp")
	lines, err := common.ReadLines(filename)
	if err != nil {
		return nil, err
	}

	linecount := len(lines)
	for i := 0; i < linecount; i++ {
		line := lines[i]
		r := strings.IndexRune(line, ':')
		if r == -1 {
			return nil, errors.New(filename + " is not fomatted correctly, expected ':'.")
		}
		proto := strings.ToLower(line[:r])
		if !protos[proto] {
			// skip protocol and data line
			i++
			continue
		}

		// Read header line
		statNames := strings.Split(line[r+2:], " ")

		// Read data line
		i++
		statValues := strings.Split(lines[i][r+2:], " ")
		if len(statNames) != len(statValues) {
			return nil, errors.New(filename + " is not fomatted correctly, expected same number of columns.")
		}
		stat := ProtoCountersStat{
			Protocol: proto,
			Stats:    make(map[string]int64, len(statNames)),
		}
		for j := range statNames {
			value, err := strconv.ParseInt(statValues[j], 10, 64)
			if err != nil {
				return nil, err
			}
			stat.Stats[statNames[j]] = value
		}
		stats = append(stats, stat)
	}
	return stats, nil
}

func VirtualMemory() (*VirtualMemoryStat, error) {
	filename := common.HostProc("meminfo")
	lines, _ := common.ReadLines(filename)
	// flag if MemAvailable is in /proc/meminfo (kernel 3.14+)
	memavail := false

	ret := &VirtualMemoryStat{}
	for _, line := range lines {
		fields := strings.Split(line, ":")
		if len(fields) != 2 {
			continue
		}
		key := strings.TrimSpace(fields[0])
		value := strings.TrimSpace(fields[1])
		value = strings.Replace(value, " kB", "", -1)

		t, err := strconv.ParseUint(value, 10, 64)
		if err != nil {
			return ret, err
		}
		switch key {
		case "MemTotal":
			ret.Total = t * 1024
		case "MemFree":
			ret.Free = t * 1024
		case "MemAvailable":
			memavail = true
			ret.Available = t * 1024
		case "Buffers":
			ret.Buffers = t * 1024
		case "Cached":
			ret.Cached = t * 1024
		case "Active":
			ret.Active = t * 1024
		case "Inactive":
			ret.Inactive = t * 1024
		case "Writeback":
			ret.Writeback = t * 1024
		case "WritebackTmp":
			ret.WritebackTmp = t * 1024
		case "Dirty":
			ret.Dirty = t * 1024
		}
	}
	if !memavail {
		ret.Available = ret.Free + ret.Buffers + ret.Cached
	}
	ret.Used = ret.Total - ret.Available
	ret.UsedPercent = float64(ret.Total-ret.Available) / float64(ret.Total) * 100.0

	return ret, nil
}

// Get memory info from /proc/(pid)/statm
func (p *Process) fillFromStatm() (*MemoryInfoStat, *MemoryInfoExStat, error) {
	pid := p.Pid
	memPath := common.HostProc(strconv.Itoa(int(pid)), "statm")
	contents, err := ioutil.ReadFile(memPath)
	if err != nil {
		return nil, nil, err
	}
	fields := strings.Split(string(contents), " ")

	vms, err := strconv.ParseUint(fields[0], 10, 64)
	if err != nil {
		return nil, nil, err
	}
	rss, err := strconv.ParseUint(fields[1], 10, 64)
	if err != nil {
		return nil, nil, err
	}
	memInfo := &MemoryInfoStat{
		RSS: rss * PageSize,
		VMS: vms * PageSize,
	}

	shared, err := strconv.ParseUint(fields[2], 10, 64)
	if err != nil {
		return nil, nil, err
	}
	text, err := strconv.ParseUint(fields[3], 10, 64)
	if err != nil {
		return nil, nil, err
	}
	lib, err := strconv.ParseUint(fields[4], 10, 64)
	if err != nil {
		return nil, nil, err
	}
	dirty, err := strconv.ParseUint(fields[5], 10, 64)
	if err != nil {
		return nil, nil, err
	}

	memInfoEx := &MemoryInfoExStat{
		RSS:    rss * PageSize,
		VMS:    vms * PageSize,
		Shared: shared * PageSize,
		Text:   text * PageSize,
		Lib:    lib * PageSize,
		Dirty:  dirty * PageSize,
	}

	return memInfo, memInfoEx, nil
}

func KernelVersion() (version string, err error) {
	filename := common.HostProc("sys/kernel/osrelease")
	if common.PathExists(filename) {
		contents, err := common.ReadLines(filename)
		if err != nil {
			return "", err
		}

		if len(contents) > 0 {
			version = contents[0]
		}
	}

	return version, nil
}

// NetFilterCounters returns iptables conntrack statistics
// the currently in use conntrack count and the max.
// If the file does not exist or is invalid it will return nil.
func FilterCounters() ([]FilterStat, error) {
	countfile := common.HostProc("sys/net/netfilter/nf_conntrackCount")
	maxfile := common.HostProc("sys/net/netfilter/nf_conntrackMax")

	count, err := common.ReadInts(countfile)

	if err != nil {
		return nil, err
	}
	stats := make([]FilterStat, 0, 1)

	max, err := common.ReadInts(maxfile)
	if err != nil {
		return nil, err
	}

	payload := FilterStat{
		ConnTrackCount: count[0],
		ConnTrackMax:   max[0],
	}

	stats = append(stats, payload)
	return stats, nil
}

// Get cmdline from /proc/(pid)/cmdline
func (p *Process) fillFromCmdline() (string, error) {
	pid := p.Pid
	cmdPath := common.HostProc(strconv.Itoa(int(pid)), "cmdline")
	cmdline, err := ioutil.ReadFile(cmdPath)
	if err != nil {
		return "", err
	}
	ret := strings.FieldsFunc(string(cmdline), func(r rune) bool {
		if r == '\u0000' {
			return true
		}
		return false
	})

	return strings.Join(ret, " "), nil
}

func SwapMemory() (*SwapMemoryStat, error) {
	sysinfo := &syscall.Sysinfo_t{}

	if err := syscall.Sysinfo(sysinfo); err != nil {
		return nil, err
	}
	ret := &SwapMemoryStat{
		Total: uint64(sysinfo.Totalswap) * uint64(sysinfo.Unit),
		Free:  uint64(sysinfo.Freeswap) * uint64(sysinfo.Unit),
	}
	ret.Used = ret.Total - ret.Free
	//check Infinity
	if ret.Total != 0 {
		ret.UsedPercent = float64(ret.Total-ret.Free) / float64(ret.Total) * 100.0
	} else {
		ret.UsedPercent = 0
	}
	filename := common.HostProc("vmstat")
	lines, _ := common.ReadLines(filename)
	for _, l := range lines {
		fields := strings.Fields(l)
		if len(fields) < 2 {
			continue
		}
		switch fields[0] {
		case "pswpin":
			value, err := strconv.ParseUint(fields[1], 10, 64)
			if err != nil {
				continue
			}
			ret.Sin = value * 4 * 1024
		case "pswpout":
			value, err := strconv.ParseUint(fields[1], 10, 64)
			if err != nil {
				continue
			}
			ret.Sout = value * 4 * 1024
		}
	}
	return ret, nil
}

func (p *Process) fillSliceFromCmdline() ([]string, error) {
	pid := p.Pid
	cmdPath := common.HostProc(strconv.Itoa(int(pid)), "cmdline")
	cmdline, err := ioutil.ReadFile(cmdPath)
	if err != nil {
		return nil, err
	}
	if len(cmdline) == 0 {
		return nil, nil
	}
	if cmdline[len(cmdline)-1] == 0 {
		cmdline = cmdline[:len(cmdline)-1]
	}
	parts := bytes.Split(cmdline, []byte{0})
	var strParts []string
	for _, p := range parts {
		strParts = append(strParts, string(p))
	}

	return strParts, nil
}

// getFileSystems returns supported filesystems from /proc/filesystems
func getFileSystems() ([]string, error) {
	filename := common.HostProc("filesystems")
	lines, err := common.ReadLines(filename)
	if err != nil {
		return nil, err
	}
	var ret []string
	for _, line := range lines {
		if !strings.HasPrefix(line, "nodev") {
			ret = append(ret, strings.TrimSpace(line))
			continue
		}
		t := strings.Split(line, "\t")
		if len(t) != 2 || t[1] != "zfs" {
			continue
		}
		ret = append(ret, strings.TrimSpace(t[1]))
	}

	return ret, nil
}