package system

import (
    "os/exec"
    "bytes"
    "hash/fnv"
    "strings"
)

// this package serves to add in wrappers for system commands to get hwinfo from the board
// this package does not actually use the hwinfo command, but rather gathers hardware info from a variety of commands

// command for model :
    // lshw -C system 2>/dev/null | head -n 1
// command for ip && mac address :
    // ifconfig eth0 | awk '/inet |ether / {print $2}'

// can combine and dump into file using
    // lshw -C system 2>/dev/null | head -n 1 > hwinfo.txt && ifconfig eth0 | awk '/inet |ether / {print $2}' >> hwinfo.txt
    // *** will just replace info in file everytime


type HWinfo struct {
    Ip string
    Id uint32
    Bus int
    Model string
    Port int
}

func NewHWinfo() (*HWinfo, error) {
    h := &HWinfo{Port:2000}
    err := h.Get()
    return h, err
}

func (h *HWinfo) Get() error {
    // responsible for filling out struct
    bus := map[string]int{"raspberrypi":1,"beaglebone":2} // eventually will replace this with a config file

    ipcmd := "ifconfig eth0 | awk '/inet / {print $2}'"
    maccmd := "ifconfig eth0 | awk '/ether / {print $2}'"
    devcmd := "lshw -C system 2>/dev/null | head -n 1"

    res := [3]bytes.Buffer{}
    var stderr bytes.Buffer
    cmds := []string{ipcmd,maccmd,devcmd}
    for i,c := range cmds {
        cmd := exec.Command("bash","-c",c)
        cmd.Stdout = &res[i]
        cmd.Stderr = &stderr
        err := cmd.Run()
        if err != nil {
            return err
        }
    }
    // formatting
    ip := res[0].String()
    ip = strings.Trim(ip," \n")
    h.Ip = ip

    hash := fnv.New32a()
    hash.Write(res[1].Bytes())
    h.Id = hash.Sum32()

    b := res[2].String()
    b = strings.Trim(b," \n")
    h.Model = b
    h.Bus = bus[b]
    return nil
}