package main

import (
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/mattn/go-gtk/glib"
)

func initBattery(a *App) {
	base := "/sys/class/power_supply"
	entries, err := os.ReadDir(base)
	if err != nil {
		fmt.Println("battery init:", err)
		return
	}

	var folder string
	for _, e := range entries {
		if strings.Contains(strings.ToLower(e.Name()), "bat") {
			folder = e.Name()
			break
		}
	}
	if folder == "" {
		fmt.Println("no battery folder found")
		return
	}
	rootPath := base + "/" + folder

	info, err := readBattery(rootPath)
	if err != nil {
		fmt.Println("read battery:", err)
		return
	}
	a.battery = info
	a.updateBatteryLabel(info)

	go func() {
		last := info
		for {
			cur, err := readBattery(rootPath)
			if err == nil &&
				(cur.Percent != last.Percent || cur.Charging != last.Charging) {
				last = cur
				a.battery = cur
				glib.IdleAdd(func() {
					a.updateBatteryLabel(cur)
				})
			}
			time.Sleep(30 * time.Second)
		}
	}()

}

func readBattery(rootPath string) (BatteryInfo, error) {
	val, err := os.ReadFile(rootPath + "/capacity")
	if err != nil {
		return BatteryInfo{}, err
	}
	status, err := os.ReadFile(rootPath + "/status")
	if err != nil {
		return BatteryInfo{}, err
	}

	p, err := strconv.Atoi(strings.TrimSpace(string(val)))
	if err != nil {
		return BatteryInfo{}, err
	}

	s := strings.ToLower(strings.TrimSpace(string(status)))
	charging := !strings.Contains(s, "dis")

	return BatteryInfo{Percent: p, Charging: charging, Path: rootPath}, nil
}