completes prometheus api functionality

cmd/tpapi/supportingFunctions.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"fmt"
+	"time"
+	"tplink/internal/tplink"
+)
+
+func switchDevice(host string, id int, state bool) (string, error) {
+	t := tplink.Tplink{
+		Host:     host,
+		SwitchID: id,
+	}
+
+	// send request to device
+	if err := t.ChangeStateMultiSwitch(state); err != nil {
+		return "", fmt.Errorf("Unable to change device state: %v\n", err)
+	}
+
+	// give device time to execute command
+	time.Sleep(100 * time.Millisecond)
+
+	// get device state
+	time.Sleep(100 * time.Millisecond)
+	sysInfo, err := t.SystemInfo()
+	if err != nil {
+		return "", fmt.Errorf("Unable to get info from target device: %v\n", err)
+	}
+
+	var ds int
+	if len(sysInfo.System.GetSysinfo.Children) == 0 {
+		ds = sysInfo.System.GetSysinfo.RelayState
+	} else {
+		ds = sysInfo.System.GetSysinfo.Children[id].State
+	}
+
+	var fs string
+	if ds == 0 {
+		fs = "OFF"
+	} else {
+		fs = "ON"
+	}
+
+	return fs, nil
+}