// +build linux

package gopsutil

import (
	"errors"
	"strconv"
	"strings"

	common "github.com/shirou/gopsutil/common"
)

func CPUTimes(percpu bool) ([]CPUTimesStat, error) {
	filename := "/proc/stat"
	var lines []string
	if percpu {
		ncpu, _ := CPUCounts(true)
		lines, _ = common.ReadLinesOffsetN(filename, 1, ncpu)
	} else {
		lines, _ = common.ReadLinesOffsetN(filename, 0, 1)
	}

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

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

	}
	return ret, nil
}

func CPUInfo() ([]CPUInfoStat, error) {
	filename := "/proc/cpuinfo"
	lines, _ := common.ReadLines(filename)

	var ret []CPUInfoStat

	var c CPUInfoStat
	for _, line := range lines {
		fields := strings.Split(line, ":")
		if len(fields) < 2 {
			if c.VendorID != "" {
				ret = append(ret, c)
			}
			continue
		}
		key := strings.TrimSpace(fields[0])
		value := strings.TrimSpace(fields[1])

		switch key {
		case "processor":
			c = CPUInfoStat{}
			t, err := strconv.ParseInt(value, 10, 32)
			if err != nil {
				return ret, err
			}
			c.CPU = int32(t)
		case "vendor_id":
			c.VendorID = value
		case "cpu family":
			c.Family = value
		case "model":
			c.Model = value
		case "model name":
			c.ModelName = value
		case "stepping":
			t, err := strconv.ParseInt(value, 10, 32)
			if err != nil {
				return ret, err
			}
			c.Stepping = int32(t)
		case "cpu MHz":
			t, err := strconv.ParseFloat(value, 64)
			if err != nil {
				return ret, err
			}
			c.Mhz = t
		case "cache size":
			t, err := strconv.ParseInt(strings.Replace(value, " KB", "", 1), 10, 32)
			if err != nil {
				return ret, err
			}
			c.CacheSize = int32(t)
		case "physical id":
			c.PhysicalID = value
		case "core id":
			c.CoreID = value
		case "cpu cores":
			t, err := strconv.ParseInt(value, 10, 32)
			if err != nil {
				return ret, err
			}
			c.Cores = int32(t)
		case "flags":
			c.Flags = strings.Split(value, ",")
		}
	}
	return ret, nil
}

func parseStatLine(line string) (*CPUTimesStat, error) {
	fields := strings.Fields(line)

	if strings.HasPrefix(fields[0], "cpu") == false {
		//		return CPUTimesStat{}, e
		return nil, errors.New("not contain cpu")
	}

	cpu := fields[0]
	if cpu == "cpu" {
		cpu = "cpu-total"
	}
	user, err := strconv.ParseFloat(fields[1], 32)
	if err != nil {
		return nil, err
	}
	nice, err := strconv.ParseFloat(fields[2], 32)
	if err != nil {
		return nil, err
	}
	system, err := strconv.ParseFloat(fields[3], 32)
	if err != nil {
		return nil, err
	}
	idle, err := strconv.ParseFloat(fields[4], 32)
	if err != nil {
		return nil, err
	}
	iowait, err := strconv.ParseFloat(fields[5], 32)
	if err != nil {
		return nil, err
	}
	irq, err := strconv.ParseFloat(fields[6], 32)
	if err != nil {
		return nil, err
	}
	softirq, err := strconv.ParseFloat(fields[7], 32)
	if err != nil {
		return nil, err
	}
	stolen, err := strconv.ParseFloat(fields[8], 32)
	if err != nil {
		return nil, err
	}
	ct := &CPUTimesStat{
		CPU:     cpu,
		User:    float32(user),
		Nice:    float32(nice),
		System:  float32(system),
		Idle:    float32(idle),
		Iowait:  float32(iowait),
		Irq:     float32(irq),
		Softirq: float32(softirq),
		Stolen:  float32(stolen),
	}
	if len(fields) > 9 { // Linux >= 2.6.11
		steal, err := strconv.ParseFloat(fields[9], 32)
		if err != nil {
			return nil, err
		}
		ct.Steal = float32(steal)
	}
	if len(fields) > 10 { // Linux >= 2.6.24
		guest, err := strconv.ParseFloat(fields[10], 32)
		if err != nil {
			return nil, err
		}
		ct.Guest = float32(guest)
	}
	if len(fields) > 11 { // Linux >= 3.2.0
		guestNice, err := strconv.ParseFloat(fields[11], 32)
		if err != nil {
			return nil, err
		}
		ct.GuestNice = float32(guestNice)
	}

	return ct, nil
}