o2: add env flag for custom config location

engine/viewmodel.go

@@ -3,7 +3,6 @@ package engine
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"o2/client"
 	"o2/games"
@@ -45,6 +44,7 @@ type ViewModel struct {
 	serverViewModel *ServerViewModel
 
 	config Config
+	configName string
 }
 
 type Config struct {
@@ -112,6 +112,25 @@ func (vm *ViewModel) NotifyView(view string, model interface{}) {
 	vn.NotifyView(view, viewModel)
 }
 
+func (vm *ViewModel) GetConfigName() string {
+	return vm.configName
+}
+
+func (vm *ViewModel) SetConfigName(configName string) {
+	vm.configName = configName
+}
+
+func (vm *ViewModel) getConfigFilePath(dir string) string {
+	path := "config.json"
+	configName := vm.GetConfigName()
+
+	if configName != "" {
+		path = "config-" + configName + ".json"
+	}
+
+	return filepath.Join(dir, path)
+}
+
 // initializes all view models:
 func (vm *ViewModel) Init() {
 	for _, model := range vm.viewModels {
@@ -141,9 +160,19 @@ func (vm *ViewModel) LoadConfiguration() bool {
 		log.Printf("viewmodel: loadConfiguration: could not find configuration directory: %v\n", err)
 		return false
 	}
-	path := filepath.Join(dir, "config.json")
+	defaultPath := filepath.Join(dir, "config.json")
+	path := vm.getConfigFilePath(dir)
 
-	b, err := ioutil.ReadFile(path)
+	var b []byte
+	err = nil
+
+	b, err = os.ReadFile(path)
+	if path != defaultPath && err != nil {
+		// fall back to default config location:
+		log.Printf("viewmodel: loadConfiguration: could not find read custom configuration file: %v\n", err)
+		b, err = os.ReadFile(defaultPath)
+	}
+
 	if err != nil {
 		log.Printf("viewmodel: loadConfiguration: could not find read configuration file: %v\n", err)
 		return false
@@ -215,10 +244,10 @@ func (vm *ViewModel) SaveConfiguration() bool {
 	if err != nil {
 		log.Printf("viewmodel: saveConfiguration: could not make directories along the path '%s': %v\n", dir, err)
 	}
+
+	path := vm.getConfigFilePath(dir)
 
-	path := filepath.Join(dir, "config.json")
-
-	err = ioutil.WriteFile(path, b, 0644)
+	err = os.WriteFile(path, b, 0644)
 	if err != nil {
 		log.Printf("viewmodel: saveConfiguration: could not write configuration file '%s': %v\n", path, err)
 		return false

webui/o2/main.go

@@ -10,6 +10,7 @@ import (
 	"o2/util/env"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -30,6 +31,8 @@ import (
 	_ "o2/games/alttp"
 )
 
+const defaultPort = 27637
+
 // build variables set via ldflags by goreleaser:
 var (
 	version string = "v0.0.0"
@@ -43,6 +46,7 @@ var (
 	listenPort  int    // port number to listen on for webserver
 	browserHost string // hostname to send as part of URL to browser to connect to webserver
 	browserUrl  string // full URL that is sent to browser (composed of browserHost:listenPort)
+	configName  string // save configuration data to a unique location
 	logPath     string
 )
 
@@ -75,6 +79,25 @@ type O2ViewModel struct {
 	Version string `json:"version"`
 }
 
+func sanitizeConfigName(s string) string {
+		var invalidChars = regexp.MustCompile(`[^\p{L}\p{N}_-]+`)
+    result := invalidChars.ReplaceAllString(s, "_")
+    result = strings.Trim(result, "._-")
+    return result
+}
+
+func resolveConfigName(configName string, listenPort int) string {
+	if configName != "" {
+		return sanitizeConfigName(configName)
+	}
+
+	if listenPort != defaultPort {
+		return strconv.Itoa(listenPort)
+	}
+
+	return ""
+}
+
 func main() {
 	defer func() {
 		if err := recover(); err != nil {
@@ -87,22 +110,26 @@ func main() {
 	// Parse env vars:
 	listenHost = env.GetOrDefault("O2_WEB_LISTEN_HOST", "0.0.0.0")
 
-	listenPort, err = strconv.Atoi(env.GetOrDefault("O2_WEB_LISTEN_PORT", "27637"))
+	listenPort, err = strconv.Atoi(env.GetOrDefault("O2_WEB_LISTEN_PORT", strconv.Itoa(defaultPort)))
 	if err != nil {
-		listenPort = 27637
+		listenPort = defaultPort
 	}
 	if listenPort <= 0 {
-		listenPort = 27637
+		listenPort = defaultPort
 	}
 	listenAddr := net.JoinHostPort(listenHost, strconv.Itoa(listenPort))
 
 	browserHost = env.GetOrDefault("O2_WEB_BROWSER_HOST", "127.0.0.1")
 	browserUrl = fmt.Sprintf("http://%s:%d/", browserHost, listenPort)
 
+	configName = resolveConfigName(env.GetOrDefault("O2_CONFIG_NAME", ""), listenPort);
+
 	// construct our viewModel:
 	viewModel := engine.NewViewModel()
 	viewModel.SetViewModel("o2", &O2ViewModel{Version: version})
 
+	viewModel.SetConfigName(configName)
+
 	// construct the web server:
 	webServer := NewWebServer(listenAddr)