// +build linux darwin

package staros

import (
	"bytes"
	"errors"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"syscall"
	"time"
)

// FindProcessByName 通过进程名来查询应用信息
func FindProcessByName(pname string) (datas []Process, err error) {
	var name, main string
	var mainb []byte
	paths, errs := ioutil.ReadDir("/proc")
	if errs != nil {
		err = errs
		return
	}
	for _, v := range paths {
		if v.IsDir() && Exists("/proc/"+v.Name()+"/comm") {
			name, err = readAsString("/proc/" + v.Name() + "/comm")
			if err != nil {
				return
			}
			if strings.TrimSpace(name) == pname {
				var tmp Process
				main, err = readAsString("/proc/" + v.Name() + "/status")
				if err != nil {
					return
				}
				data := splitBy(main, ":")
				tmp.Name = pname
				tmp.Pid, _ = strconv.ParseInt(data["Pid"], 10, 64)
				tmp.PPid, _ = strconv.ParseInt(data["PPid"], 10, 64)
				tmp.TPid, _ = strconv.ParseInt(data["TracerPid"], 10, 64)
				uids := splitBySpace(data["Uid"])
				gids := splitBySpace(data["Gid"])
				tmp.RUID, _ = strconv.Atoi(uids[0])
				tmp.EUID, _ = strconv.Atoi(uids[1])
				tmp.RGID, _ = strconv.Atoi(gids[0])
				tmp.EGID, _ = strconv.Atoi(gids[1])
				mainb, err = ioutil.ReadFile("/proc/" + v.Name() + "/cmdline")
				if err != nil {
					return
				}
				args := bytes.Split(mainb, []byte{0})
				for _, v := range args {
					tmp.Args = append(tmp.Args, string(v))
				}
				tmp.LocalPath, err = os.Readlink("/proc/" + v.Name() + "/exe")
				if err != nil {
					return
				}
				tmp.Path = tmp.LocalPath
				tmp.LocalPath = filepath.Dir(tmp.LocalPath)
				tmp.ExecPath, err = os.Readlink("/proc/" + v.Name() + "/cwd")
				if err != nil {
					return
				}
				main, err = readAsString("/proc/" + v.Name() + "/stat")
				if err != nil {
					return
				}
				times := splitBySpace(main)
				uptime, _ := strconv.ParseInt(strings.TrimSpace(times[21]), 10, 64)
				tmp.Uptime = time.Unix(StartTime().Unix()+uptime/100, int64((float64(uptime)/100-float64(uptime/100))*1000000000))
				datas = append(datas, tmp)
			}
		}
	}
	return
}

// FindProcessByPid 通过Pid来查询应用信息
func FindProcessByPid(pid int64) (datas Process, err error) {
	var name, main string
	var mainb []byte
	if !Exists("/proc/" + fmt.Sprint(pid) + "/comm") {
		err = errors.New("Not Found")
		return
	}
	name, err = readAsString("/proc/" + fmt.Sprint(pid) + "/comm")
	if err != nil {
		return
	}
	main, err = readAsString("/proc/" + fmt.Sprint(pid) + "/status")
	if err != nil {
		return
	}
	data := splitBy(main, ":")
	datas.Name = strings.TrimSpace(name)
	datas.Pid, _ = strconv.ParseInt(data["Pid"], 10, 64)
	datas.PPid, _ = strconv.ParseInt(data["PPid"], 10, 64)
	datas.TPid, _ = strconv.ParseInt(data["TracerPid"], 10, 64)
	uids := splitBySpace(data["Uid"])
	gids := splitBySpace(data["Gid"])
	datas.RUID, _ = strconv.Atoi(uids[0])
	datas.EUID, _ = strconv.Atoi(uids[1])
	datas.RGID, _ = strconv.Atoi(gids[0])
	datas.EGID, _ = strconv.Atoi(gids[1])
	mainb, err = ioutil.ReadFile("/proc/" + fmt.Sprint(pid) + "/cmdline")
	if err != nil {
		return
	}
	args := bytes.Split(mainb, []byte{0})
	for _, v := range args {
		datas.Args = append(datas.Args, string(v))
	}
	datas.LocalPath, err = os.Readlink("/proc/" + fmt.Sprint(pid) + "/exe")
	if err != nil {
		return
	}
	datas.Path = datas.LocalPath
	datas.LocalPath = filepath.Dir(datas.LocalPath)
	datas.ExecPath, err = os.Readlink("/proc/" + fmt.Sprint(pid) + "/cwd")
	if err != nil {
		return
	}
	main, err = readAsString("/proc/" + fmt.Sprint(pid) + "/stat")
	if err != nil {
		return
	}
	times := splitBySpace(main)
	uptime, _ := strconv.ParseInt(strings.TrimSpace(times[21]), 10, 64)
	datas.Uptime = time.Unix(StartTime().Unix()+uptime/100, int64((float64(uptime)/100-float64(uptime/100))*1000000000))
	return
}

func Daemon(path string, args ...string) (int, error) {
	cmd := exec.Command(path, args...)
	cmd.SysProcAttr = &syscall.SysProcAttr{
		Setsid: true,
	}
	if err := cmd.Start(); err != nil {
		return -1, err
	}
	pid := cmd.Process.Pid
	err := cmd.Process.Release()
	return pid, err
}

func (starcli *StarCmd) SetRunUser(uid, gid uint32) {
	starcli.CMD.SysProcAttr = &syscall.SysProcAttr{
		Credential: &syscall.Credential{
			Uid: uid,
			Gid: gid,
		},
		Setsid: true,
	}
}

func (starcli *StarCmd) Release() error {
	if err := starcli.CMD.Start(); err != nil {
		return err
	}
	starcli.CMD.SysProcAttr = &syscall.SysProcAttr{
		Setsid: true,
	}
	starcli.CMD.Process.Release()
	return nil
}

func (starcli *StarCmd) SetKeepCaps() error {
	_, _, err := syscall.RawSyscall(157 /*SYS PRCTL */, 0x8 /*PR SET KEEPCAPS*/, 1, 0)
	if 0 != err {
		return err
	}
	return nil
}