1 files changed, 176 insertions, 0 deletions
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..60de258
--- /dev/null
+++ b/main.go
@@ -0,0 +1,176 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+type Configuration struct {
+	Listen string
+	Vcp string
+}
+
+var configuration = Configuration{
+	Listen: "127.0.0.1:49281",
+	Vcp: "10"}
+
+type Brightness struct {
+	Lock         bool
+	Value        int
+	ToggledValue int
+}
+
+var currentBrightness Brightness
+
+func update() {
+	if currentBrightness.Lock == false {
+		currentBrightness.Lock = true
+		cmd := exec.Command("ddcutil", "getvcp", "--brief", configuration.Vcp)
+		log.Println(cmd.String())
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		outString := strings.Split(strings.Trim(string(out), "\n"), " ")
+		currentBrightness.Value, err = strconv.Atoi(outString[len(outString)-2])
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		log.Println("Current brightness is", currentBrightness.Value)
+		currentBrightness.Lock = false
+	} else {
+		log.Println("Active lock, no operation performed")
+		return
+	}
+}
+
+func get(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "GET" {
+                log.Println("Current brightness cached value is",
+			currentBrightness.Value)
+	}
+}
+
+func ddcutilSetBrightness(brightness Brightness) {
+	if currentBrightness.Lock == false {
+		currentBrightness.Lock = true
+		cmd := exec.Command("ddcutil", "setvcp", configuration.Vcp,
+			strconv.Itoa(brightness.Value))
+		log.Println(cmd.String())
+		_, err := cmd.CombinedOutput()
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		currentBrightness.Value = brightness.Value
+		currentBrightness.Lock = false
+	} else {
+		log.Println("Active lock, no operation performed")
+		return
+	}
+}
+
+func set(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "POST" {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		var brightness Brightness
+		json.Unmarshal([]byte(body), &brightness)
+		ddcutilSetBrightness(brightness)
+	}
+}
+
+func decrease(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "POST" {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		var brightness Brightness
+		json.Unmarshal([]byte(body), &brightness)
+		newValue := Brightness{Value: currentBrightness.Value - brightness.Value}
+		if newValue.Value < 0 {
+			log.Println("Brightness is minimum")
+		} else {
+			ddcutilSetBrightness(newValue)
+			log.Println("Current brightness is", currentBrightness.Value)
+		}
+	} else {
+		log.Println("Active lock, no operation performed")
+		return
+	}
+}
+
+func increase(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "POST" {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		var brightness Brightness
+		json.Unmarshal([]byte(body), &brightness)
+		newValue := Brightness{Value: currentBrightness.Value + brightness.Value}
+		if newValue.Value > 100 {
+			log.Println("Brightness is maximum")
+		} else {
+			ddcutilSetBrightness(newValue)
+			log.Println("Current brightness is", currentBrightness.Value)
+		}
+	} else {
+		log.Println("Active lock, no operation performed")
+		return
+	}
+}
+
+func toggle(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "POST" {
+		if currentBrightness.Value == 0 {
+			ddcutilSetBrightness(Brightness{Value: currentBrightness.ToggledValue})
+			log.Println("Current brightness is", currentBrightness.Value)
+		} else {
+			currentBrightness.ToggledValue = currentBrightness.Value
+			ddcutilSetBrightness(Brightness{Value: 0})
+			log.Println("Current brightness is", currentBrightness.Value)
+		}
+	}
+}
+
+func main() {
+	jsonFile, err := os.Open("ddcutil-daemon.json")
+	if err != nil {
+		log.Fatalln(err)
+	}
+	byteValue, err := ioutil.ReadAll(jsonFile)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	var configuration Configuration
+	json.Unmarshal(byteValue, &configuration)
+	jsonFile.Close()
+
+	currentBrightness.Lock = false
+	update()
+	http.HandleFunc("/update", func(w http.ResponseWriter, r *http.Request) {
+		update()
+	})
+	http.HandleFunc("/get", get)
+	http.HandleFunc("/set", set)
+	http.HandleFunc("/decrease", decrease)
+	http.HandleFunc("/increase", increase)
+	http.HandleFunc("/toggle", toggle)
+	log.Fatal(http.ListenAndServe(configuration.Listen, nil))
+}