Rework code documentation

Comments inside functions are not that helpful. While the functino
docstring should explain everything to a user, the implementation inside
should speak for itself.

2 files changed, 2 insertions, 19 deletions

diff --git a/hs100.go b/hs100.go
index ff25576..f08c7de 100644
--- a/hs100.go
+++ b/hs100.go
@@ -26,18 +26,15 @@ type Hs100Conf struct {
 // encrypt() encrypts data for a TP-Link WiFi plug.
 func encrypt(data []byte) ([]byte, error) {
 
-	// assert maximum payload size to cast data length safely
 	if len(data) > MAX_PAYLOAD {
 		return []byte{}, fmt.Errorf("Too many bytes to encrypt (%d > %d)!\n",
 			len(data), MAX_PAYLOAD)
 	}
 	length := uint32(len(data))
 
-	// encode payload length as header
-	out := make([]byte, 4) // header buffer
+	out := make([]byte, 4)
 	binary.BigEndian.PutUint32(out, length)
 
-	// encryption algorithm
 	key := byte(171)
 	for _, value := range data {
 		key = key ^ value
@@ -52,10 +49,8 @@ func decrypt(data []byte) []byte {
 
 	// TODO check if length given in header is correct
 
-	// cut-off header
 	data = data[4:]
 
-	// decryption algorithm
 	key := byte(171)
 	for index, value := range data {
 		data[index] = key ^ value
@@ -68,19 +63,16 @@ func decrypt(data []byte) []byte {
 // send() sends data via TCP to an address (like "192.168.1.42:9999").
 func send(address string, data []byte) error {
 
-	// create a Dialer with context
 	var d net.Dialer
 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 	defer cancel()
 
-	// establish connection
 	conn, err := d.DialContext(ctx, "tcp", address)
 	if err != nil {
 		return fmt.Errorf("Failed to dial: %v", err)
 	}
 	defer conn.Close()
 
-	// writing data
 	_, err = conn.Write(data)
 	if err != nil {
 		return fmt.Errorf("Could not write data: %v", err)
@@ -95,7 +87,6 @@ func set(host string, state string) error {
 
 	cmd := ""
 
-	// modify command according to state
 	if state == "on" {
 		cmd = `{"system":{"set_relay_state":{"state":1}}}`
 	} else if state == "off" {
@@ -104,7 +95,6 @@ func set(host string, state string) error {
 		return fmt.Errorf("set() just accepts values 'on' and 'off'!")
 	}
 
-	// format address, encrypt data and send it
 	address := fmt.Sprintf("%s:9999", host)
 	data, err := encrypt([]byte(cmd))
 	if err != nil {
diff --git a/main.go b/main.go
index 637f7d1..a99b46b 100644
--- a/main.go
+++ b/main.go
@@ -28,7 +28,6 @@ type WebConfig struct {
 	Listen netip.AddrPort
 }
 
-// main() contains the control flow of this program.
 func main() {
 	configPath := parseFlags()
 	c := parseConfig(configPath)
@@ -42,7 +41,7 @@ func main() {
 // parseFlags() handles command line interface (CLI) flags.
 func parseFlags() string {
 
-	var r string // return value
+	var r string
 
 	flag.StringVar(&r, "c", "/etc/webiot/config.json",
 		"path to configuration file")
@@ -57,13 +56,11 @@ func parseFlags() string {
 // returns it as Go datastructure.
 func parseConfig(path string) RuntimeConfig {
 
-	// read config file and ensure proper JSON formatting
 	data := mustRead(path)
 	if !json.Valid(data) {
 		log.Fatalf("%s contains invalid JSON!", path)
 	}
 
-	// read to RuntimeConfig struct and handle errors
 	config := RuntimeConfig{}
 	err := json.Unmarshal(data, &config)
 	if err != nil {
@@ -76,7 +73,6 @@ func parseConfig(path string) RuntimeConfig {
 // index() returns a HTTP handler for the index page.
 func index(devices DevicesConfig, appdata string) func(http.ResponseWriter, *http.Request) {
 
-	// prepare HTML
 	path := filepath.Join(appdata, "index.html.tmpl")
 	html := mustRender(path, devices)
 
@@ -87,7 +83,6 @@ func index(devices DevicesConfig, appdata string) func(http.ResponseWriter, *htt
 
 func css(appdata string) func(http.ResponseWriter, *http.Request) {
 
-	// read CSS file
 	path := filepath.Join(appdata, "simple.css")
 	css := string(mustRead(path))
 
@@ -128,7 +123,6 @@ func api() func(http.ResponseWriter, *http.Request) {
 
 		// TODO assert correct HTTP method
 
-		// read parameters and handle errors
 		errHost, host := assertSingleParam(r, "host")
 		errState, state := assertSingleParam(r, "state")
 		if (errHost != nil) || (errState != nil) {
@@ -137,7 +131,6 @@ func api() func(http.ResponseWriter, *http.Request) {
 			return
 		}
 
-		// set WiFi plug
 		err := set(host, state)
 		if err != nil {
 			http.Error(w, "Could not set WiFi plug.", 500)