From 7fa06dd8ce849ef9e7231c44ed0be73ab399ee9e Mon Sep 17 00:00:00 2001
From: Niklas <niklas@kapelle.org>
Date: Tue, 26 Jan 2021 23:32:19 +0100
Subject: [PATCH] initial commit

---
 exampleLayout.yaml |  10 ++++
 go.mod             |   9 +++
 go.sum             |   7 +++
 opendock.go        | 143 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 169 insertions(+)
 create mode 100644 exampleLayout.yaml
 create mode 100644 go.mod
 create mode 100644 go.sum
 create mode 100644 opendock.go

diff --git a/exampleLayout.yaml b/exampleLayout.yaml
new file mode 100644
index 0000000..25484ba
--- /dev/null
+++ b/exampleLayout.yaml
@@ -0,0 +1,10 @@
+buttons:
+  - title: Click me
+    exec: notify-send "Click me"
+    pos: 0
+  - title: Also click me
+    exec: notify-send "Also click me"
+    pos: 1
+  - title: Click click
+    exec: notify-send "Click click"
+    pos: 2
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..917c6ca
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,9 @@
+module git.kapelle.org/niklas/opendock-backend
+
+go 1.15
+
+require (
+	github.com/gorilla/websocket v1.4.2
+	gopkg.in/yaml.v2 v2.4.0
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..18c5e9f
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,7 @@
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/opendock.go b/opendock.go
new file mode 100644
index 0000000..a2f7db9
--- /dev/null
+++ b/opendock.go
@@ -0,0 +1,143 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os/exec"
+
+	"github.com/gorilla/websocket"
+	"gopkg.in/yaml.v2"
+)
+
+type baseMessage struct {
+	MessageType string `json:"messageType"`
+}
+
+// message type "buttonPress"
+type buttonPressMessage struct {
+	ButtonIndex int  `json:"buttonIndex"`
+	Long        bool `json:"long"`
+}
+
+type buttonLayoutConfig struct {
+	Buttons []buttonConfig `yaml:"buttons" json:"buttons"`
+}
+
+type buttonConfig struct {
+	Title string `yaml:"title" json:"title"`
+	Exec  string `yaml:"exec"`
+	Pos   int    `yaml:"pos" json:"pos"`
+}
+
+var upgrader = websocket.Upgrader{}
+var buttonLayout buttonLayoutConfig
+
+func upgradeWebsocket(w http.ResponseWriter, r *http.Request) {
+	c, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		log.Print("Failed to upgrade connection:", err)
+		return
+	}
+	log.Print("New device connected")
+	eventLoop(c)
+}
+
+func eventLoop(c *websocket.Conn) {
+	defer c.Close()
+	for {
+		_, rawMessage, err := c.ReadMessage()
+		if err != nil {
+			log.Println("Failed to read message: ", err)
+			break
+		}
+
+		var base baseMessage
+
+		err = json.Unmarshal(rawMessage, &base)
+		if err != nil {
+			log.Printf("Failed to parse base message: %s", err.Error())
+			continue
+		}
+
+		response, err := handleMessage(base, rawMessage)
+		if err != nil {
+			log.Printf("Failed to handle message: %s", err.Error())
+		} else {
+			if response != nil {
+				c.WriteMessage(websocket.TextMessage, *response)
+			}
+		}
+	}
+}
+
+// handleMessage forwards the message to the handler
+func handleMessage(base baseMessage, raw []byte) (*[]byte, error) {
+	switch base.MessageType {
+	case "buttonPress":
+		var msg buttonPressMessage
+		err := json.Unmarshal(raw, &msg)
+		if err != nil {
+			return nil, err
+		}
+		handleButtonPress(msg)
+	case "layout":
+		val, err := json.Marshal(buttonLayout)
+		return &val, err
+
+	default:
+		return nil, errors.New("Unmachted message type: " + base.MessageType)
+	}
+
+	return nil, nil
+}
+
+// handleButtonPress handle the press of a button on the app
+func handleButtonPress(msg buttonPressMessage) {
+	log.Printf("Button press. Index: %d", msg.ButtonIndex)
+	// Find button in layout
+	for i := 0; i < len(buttonLayout.Buttons); i++ {
+		if buttonLayout.Buttons[i].Pos == msg.ButtonIndex {
+			command := buttonLayout.Buttons[i].Exec
+			go runCommand(command)
+			break
+		}
+	}
+
+}
+
+func runCommand(command string) {
+	cmd := exec.Command("sh", "-c", command)
+	cmd.Run()
+}
+
+// loadLayout loads the layout file
+func loadLayout(filePath string) (*buttonLayoutConfig, error) {
+	file, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		return nil, err
+	}
+
+	var layout buttonLayoutConfig
+
+	err = yaml.Unmarshal(file, &layout)
+	if err != nil {
+		return nil, err
+	}
+
+	return &layout, nil
+}
+
+func main() {
+	loadedLayout, err := loadLayout("exampleLayout.yaml")
+	if err != nil {
+		log.Fatalf("Failed to load layout: %s", err.Error())
+	}
+
+	buttonLayout = *loadedLayout
+
+	http.HandleFunc("/ws", upgradeWebsocket)
+	log.Fatal(http.ListenAndServe(":8069", nil))
+}