go rewrite

internal/battery/battery.go

@@ -0,0 +1,71 @@
+package battery
+
+import (
+	"os"
+	"strings"
+	"time"
+
+	"gomon/internal/exec"
+	"gomon/internal/logger"
+	"gomon/internal/model"
+)
+
+// battery monitor service
+func Monitor(bat model.Battery, profiles ...string) error {
+	// wait a while if needed
+	startupWait := os.Getenv("STARTUP_WAIT")
+	if startupWait != "" {
+		duration, err := time.ParseDuration(startupWait)
+		if err != nil {
+			logger.Error("Invalid STARTUP_WAIT duration")
+			return nil
+		}
+		time.Sleep(duration)
+	}
+
+	// start the monitor loop
+	var prevProfile string
+	for {
+		// read the current state
+		batteryStatus, err := os.ReadFile(bat.Path + "/status")
+		if err != nil {
+			logger.Error("Failed to read battery status")
+			return nil
+		}
+		currentProfile := "performance"
+		if strings.TrimSpace(string(batteryStatus)) == "Discharging" {
+			currentProfile = "balanced"
+		}
+
+		// set the new profile
+		if currentProfile != prevProfile {
+			logger.Info("Setting power profile to %s for battery %s", currentProfile, bat.Path)
+			var commandArgs []string
+			if bat.Command != "" {
+				commandArgs = strings.Split(bat.Command, " ")
+			} else {
+				commandArgs = []string{"powerprofilesctl", "set", currentProfile}
+			}
+			err = exec.ExecCommand(commandArgs[0], commandArgs[1:]...)
+			if err != nil {
+				logger.Error("Failed to execute command")
+				return nil
+			}
+
+			// execute the extra command
+            // if any
+			if bat.ExtraCommand != "" {
+				extraCommandArgs := strings.Split(bat.ExtraCommand, " ")
+				err = exec.ExecCommand(extraCommandArgs[0], extraCommandArgs[1:]...)
+				if err != nil {
+					logger.Error("Failed to execute extra command")
+					return nil
+				}
+			}
+		}
+		prevProfile = currentProfile
+
+		// wait for the next power change event
+		time.Sleep(1 * time.Second)
+	}
+}

internal/config/config.go

@@ -0,0 +1,29 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+
+	"gomon/internal/logger"
+	"gomon/internal/model"
+)
+
+// Load loads the battery configuration from a file.
+func Load(filename string) (model.BatteryConfig, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		logger.Error("Failed to open file")
+		return model.BatteryConfig{}, err
+	}
+	defer file.Close()
+
+	var config model.BatteryConfig
+	decoder := json.NewDecoder(file)
+	err = decoder.Decode(&config)
+	if err != nil {
+		logger.Error("Failed to decode JSON")
+		return model.BatteryConfig{}, err
+	}
+
+	return config, nil
+}

internal/exec/exec.go

@@ -0,0 +1,21 @@
+package exec
+
+import (
+	"os/exec"
+
+	"gomon/internal/logger"
+)
+
+// execute a command with args and returns its output
+// this will be used primarily for executing external commands if configured
+// or executing bash commands verbatim
+func ExecCommand(name string, arg ...string) error {
+	cmd := exec.Command(name, arg...)
+	err := cmd.Run()
+	if err != nil {
+		logger.Error("Failed to execute command")
+		return err
+	}
+
+	return nil
+}

internal/logger/logger.go

@@ -0,0 +1,24 @@
+package logger
+
+import (
+	"github.com/sirupsen/logrus"
+)
+
+var Log *logrus.Logger
+
+func init() {
+	Log = logrus.New()
+	Log.SetFormatter(&logrus.JSONFormatter{})
+}
+
+func Info(format string, v ...interface{}) {
+	Log.Infof(format, v...)
+}
+
+func Error(format string, v ...interface{}) {
+	Log.Errorf(format, v...)
+}
+
+func Fatal(format string, v ...interface{}) {
+	Log.Fatalf(format, v...)
+}

internal/model/model.go

@@ -0,0 +1,11 @@
+package model
+
+type Battery struct {
+	Path         string `json:"path"`
+	Command      string `json:"command"`
+	ExtraCommand string `json:"extraCommand"`
+}
+
+type BatteryConfig struct {
+	BatPaths []Battery `json:"batPaths"`
+}