Refactor: Split into more packages to reduce server binary size

global/deviceIDs.go

@@ -0,0 +1,36 @@
+package global
+
+import (
+	"io/fs"
+	"os"
+
+	"github.com/rwinkhart/go-boilerplate/back"
+)
+
+// GetOldDeviceID returns the current device ID or
+// FSMisc if there is no device ID (e.g. first run).
+func GetCurrentDeviceID() string {
+	deviceIDList := GenDeviceIDList(false) // errorOnFail is false so that nil is received when the devices directory does not exist
+	var deviceID string
+	if len(deviceIDList) > 0 {
+		deviceID = (deviceIDList)[0].Name()
+	} else {
+		deviceID = FSMisc // indicates to server that no device ID is being replaced
+	}
+	return deviceID
+}
+
+// GenDeviceIDList returns a slice of all registered device IDs.
+// Requires: errorOnFail (set to true to throw an error if the devices directory cannot be read/does not exist)
+func GenDeviceIDList(errorOnFail bool) []fs.DirEntry {
+	// create a slice of all registered devices
+	deviceIDList, err := os.ReadDir(ConfigDir + PathSeparator + "devices")
+	if err != nil {
+		if errorOnFail {
+			back.PrintError("Failed to read the devices directory: "+err.Error(), back.ErrorRead, true)
+		} else {
+			return nil // a nil return value indicates that the devices directory could not be read/does not exist
+		}
+	}
+	return deviceIDList
+}