package main

import (
	"encoding/csv"
	"fmt"
	"log"
	"os"
	"runtime"
	"strconv"
	"strings"
	"time"
)

func readTemp() string {
	temperatureFilePath := "/sys/class/hwmon/hwmon6/temp1_input"
	f, err := os.ReadFile(temperatureFilePath)

	if err != nil {
		log.Fatal(err)
	}
	//defer f.Close()
	tempFloat, err := strconv.ParseFloat(strings.Fields(string(f))[0], 32)
	if err != nil {
		log.Fatal(err)
	}

	tempFloat = tempFloat / 1000

	return string(fmt.Sprintf("%f", tempFloat))
}

func writeCsv(temp string, load string) {
	// Input: temp, load
	// Result: write data to CSV file
	t := time.Now()
	timestamp := t.Unix()
	targetFile := "lin_temp_mon.csv"
	fmt.Println(temp, load, timestamp)

	targetArr := []string{strconv.FormatInt(timestamp, 10), load, temp}

	f, err := os.OpenFile(targetFile, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
	if err != nil {
		log.Fatal("Error: ", err)
		return
	}
	w := csv.NewWriter(f)
	err = w.Write(targetArr)
	if err != nil {
		log.Fatal("Error: ", err)
		return
	}
	w.Flush()
	f.Close()
}

func getPerCPU() string {
	loadavgFile := "/proc/loadavg"
	nproc := float64(runtime.NumCPU())

	loadAvgRaw, err := os.ReadFile(loadavgFile)

	if err != nil {
		log.Fatal(err)
	}
	//defer loadAvgRaw.Close()

	loadAvgCur, err := strconv.ParseFloat(strings.Fields(string(loadAvgRaw))[0], 32)

	loadPerCpu := loadAvgCur / nproc

	return string(fmt.Sprintf("%f", loadPerCpu))

}

func main() {
	// Timestamp, LA, Temp
	writeCsv(readTemp(), getPerCPU())
}