Added UI for plugin system and upnp example

- Added wip UI for plugin tag system
- Added upnp port forwarder plugin
- Added error and fatal printout for plugins
- Optimized UI flow for plugin context window
- Added dev web server for plugin development purpose

example/plugins/upnp/main.go

@@ -0,0 +1,194 @@
+package main
+
+import (
+	"embed"
+	_ "embed"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"strconv"
+	"time"
+
+	"plugins.zoraxy.aroz.org/zoraxy/upnp/mod/upnpc"
+	plugin "plugins.zoraxy.aroz.org/zoraxy/upnp/mod/zoraxy_plugin"
+)
+
+const (
+	PLUGIN_ID           = "org.aroz.zoraxy.plugins.upnp"
+	UI_PATH             = "/ui"
+	WEB_ROOT            = "/www"
+	CONFIG_FILE         = "upnp.json"
+	AUTO_RENEW_INTERVAL = 12 * 60 * 60 // 12 hours
+)
+
+type PortForwardRecord struct {
+	RuleName   string
+	PortNumber int
+}
+
+type UPnPConfig struct {
+	ForwardRules []*PortForwardRecord
+	Enabled      bool
+}
+
+//go:embed www/*
+var content embed.FS
+
+// Runtime variables
+var (
+	upnpRouterExists  bool        = false
+	upnpRuntimeConfig *UPnPConfig = &UPnPConfig{
+		ForwardRules: []*PortForwardRecord{},
+		Enabled:      false,
+	}
+	upnpClient      *upnpc.UPnPClient = nil
+	renewTickerStop chan bool
+)
+
+func main() {
+	//Handle introspect
+	runtimeCfg, err := plugin.ServeAndRecvSpec(&plugin.IntroSpect{
+		ID:            PLUGIN_ID,
+		Name:          "UPnP Forwarder",
+		Author:        "aroz.org",
+		AuthorContact: "https://github.com/aroz-online",
+		Description:   "A UPnP Port Forwarder Plugin for Zoraxy",
+		URL:           "https://github.com/aroz-online",
+		Type:          plugin.PluginType_Utilities,
+		VersionMajor:  1,
+		VersionMinor:  0,
+		VersionPatch:  0,
+		UIPath:        UI_PATH,
+	})
+	if err != nil {
+		//Terminate or enter standalone mode here
+		fmt.Println("This is a plugin for Zoraxy and should not be run standalone\n Visit zoraxy.aroz.org to download Zoraxy.")
+		panic(err)
+	}
+
+	//Read the configuration from file
+	if _, err := os.Stat(CONFIG_FILE); os.IsNotExist(err) {
+		err = os.WriteFile(CONFIG_FILE, []byte("{}"), 0644)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	cfgBytes, err := os.ReadFile(CONFIG_FILE)
+	if err != nil {
+		panic(err)
+	}
+
+	//Load the configuration
+	err = json.Unmarshal(cfgBytes, &upnpRuntimeConfig)
+	if err != nil {
+		panic(err)
+	}
+
+	//Start upnp client and auto-renew ticker
+	go func() {
+		TryStartUPnPClient()
+	}()
+
+	//Serve the plugin UI
+	embedWebRouter := plugin.NewPluginEmbedUIRouter(PLUGIN_ID, &content, WEB_ROOT, UI_PATH)
+	// For debugging, use the following line instead
+	//embedWebRouter := plugin.NewPluginFileSystemUIRouter(PLUGIN_ID, "."+WEB_ROOT, UI_PATH)
+	//embedWebRouter.EnableDebug = true
+	embedWebRouter.RegisterTerminateHandler(func() {
+		if renewTickerStop != nil {
+			renewTickerStop <- true
+		}
+		// Do cleanup here if needed
+		upnpClient.Close()
+	}, nil)
+	embedWebRouter.AttachHandlerToMux(nil)
+
+	//Serve the API
+	RegisterAPIs()
+
+	//Start the IO server
+	fmt.Println("UPnP Forwarder started at http://127.0.0.1:" + strconv.Itoa(runtimeCfg.Port))
+	err = http.ListenAndServe("127.0.0.1:"+strconv.Itoa(runtimeCfg.Port), nil)
+	if err != nil {
+		panic(err)
+	}
+}
+
+// RegisterAPIs registers the APIs for the plugin
+func RegisterAPIs() {
+	http.HandleFunc(UI_PATH+"/api/usable", handleUsableState)
+	http.HandleFunc(UI_PATH+"/api/enable", handleEnableState)
+	http.HandleFunc(UI_PATH+"/api/forward", handleForwardPort)
+	http.HandleFunc(UI_PATH+"/api/edit", handleForwardPortEdit)
+	http.HandleFunc(UI_PATH+"/api/remove", handleForwardPortRemove)
+}
+
+// TryStartUPnPClient tries to start the UPnP client
+func TryStartUPnPClient() {
+	if renewTickerStop != nil {
+		renewTickerStop <- true
+	}
+
+	// Create UPnP client
+	upnpClient, err := upnpc.NewUPNPClient()
+	if err != nil {
+		upnpRouterExists = false
+		upnpRuntimeConfig.Enabled = false
+		fmt.Println("UPnP router not found")
+		SaveRuntimeConfig()
+		return
+	}
+	upnpRouterExists = true
+
+	//Check if the client is enabled by default
+	if upnpRuntimeConfig.Enabled {
+		// Forward all the ports
+		for _, rule := range upnpRuntimeConfig.ForwardRules {
+			err = upnpClient.ForwardPort(rule.PortNumber, rule.RuleName)
+			if err != nil {
+				fmt.Println("Unable to forward port", rule.PortNumber, ":", err)
+				return
+			}
+		}
+	}
+
+	// Start the auto-renew ticker
+	_, renewTickerStop = SetupAutoRenewTicker()
+}
+
+// SetupAutoRenewTicker sets up a ticker for auto-renewing the port forwarding rules
+func SetupAutoRenewTicker() (*time.Ticker, chan bool) {
+	ticker := time.NewTicker(AUTO_RENEW_INTERVAL * time.Second)
+	closeChan := make(chan bool)
+	go func() {
+		for {
+			select {
+			case <-closeChan:
+				ticker.Stop()
+				return
+			case <-ticker.C:
+				if upnpClient != nil {
+					upnpClient.RenewForwardRules()
+				}
+			}
+		}
+	}()
+	return ticker, closeChan
+}
+
+// SaveRuntimeConfig saves the runtime configuration to file
+func SaveRuntimeConfig() error {
+	cfgBytes, err := json.Marshal(upnpRuntimeConfig)
+	if err != nil {
+		return err
+	}
+
+	err = os.WriteFile(CONFIG_FILE, cfgBytes, 0644)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}