Refactored code and added support for kasa smart plugs

kasa/kasa.go

@@ -0,0 +1,88 @@
+package kasa
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"net"
+)
+
+func encrypt(data []byte) []byte {
+	var key byte = 171
+	buf := new(bytes.Buffer)
+	binary.Write(buf, binary.BigEndian, uint32(len(data)))
+
+	for _, c := range []byte(data) {
+		a := key ^ c
+		key = a
+		buf.WriteByte(a)
+	}
+
+	return buf.Bytes()
+}
+
+func decrypt(data []byte) string {
+	var key byte = 171
+	buf := new(bytes.Buffer)
+	binary.Write(buf, binary.BigEndian, uint32(len(data)))
+
+	for _, c := range data {
+		a := key ^ c
+		key = c
+		buf.WriteByte(a)
+	}
+
+	return string(buf.Bytes())
+}
+
+
+type Kasa struct {
+	ip string
+}
+
+func New(ip string) Kasa {
+	return Kasa{ip}
+}
+
+func (kasa *Kasa) sendCmd(cmd cmd) {
+	con, err := net.Dial("tcp", fmt.Sprintf("%s:9999", kasa.ip))
+	if err != nil {
+		panic(err)
+	}
+
+	defer con.Close()
+
+	b, err := json.Marshal(cmd)
+	if err != nil {
+		panic(err)
+	}
+
+	_, err = con.Write(encrypt(b))
+	if err != nil {
+		panic(err)
+	}
+
+	resp := make([]byte, 2048)
+	_, err = con.Read(resp)
+	if err != nil {
+		panic(err)
+	}
+
+	var reply reply
+	json.Unmarshal(resp, &reply)
+
+	if reply.System.SetRelayState.ErrCode != 0 {
+		fmt.Println(reply)
+		fmt.Println(resp)
+	}
+}
+
+func (kasa *Kasa) SetState(on bool) {
+	var cmd cmd
+	if on {
+		cmd.System.SetRelayState.State = 1
+	}
+
+	kasa.sendCmd(cmd)
+}

kasa/reply.go

@@ -0,0 +1,19 @@
+package kasa
+
+type errCode struct {
+	ErrCode int
+}
+
+type reply struct {
+	System struct {
+		SetRelayState errCode `json:"set_relay_state"`
+	} `json:"system"`
+}
+
+type cmd struct {
+	System struct {
+		SetRelayState struct {
+			State int `json:"state"`
+		} `json:"set_relay_state"`
+	} `json:"system"`
+}