package chill

import (
	"bytes"
	"context"
	"errors"
	"os"
	"strconv"
	"time"
)

var TempFile string = "/sys/class/thermal/thermal_zone2/temp"
var MaxTemp int = 72500
var Sleep = time.Second * 10
var ErrChilledOut = errors.New("temperature dropped below threshold")

func Chill(baseCtx context.Context) context.Context {
	ctx, cancel := context.WithCancelCause(baseCtx)

	go func() {
		var by []byte
		var err error
		current := MaxTemp + 1

		for current >= MaxTemp {
			by, err = os.ReadFile(TempFile)
			if err != nil {
				cancel(err)
				return
			}

			by = bytes.TrimSpace(by)
			current, err = strconv.Atoi(string(by))
			if err != nil {
				cancel(err)
				return
			}
			if current < MaxTemp {
				break
			}
			time.Sleep(Sleep)
		}
		cancel(ErrChilledOut)
	}()

	return ctx
}