Simplify GUI settings and build flags

internal/app/runtime.go

@@ -2,13 +2,45 @@ package app
 
 import (
 	"fmt"
+	"io"
+	"log"
 	"os"
 	"path/filepath"
+	"sync"
 	"time"
 
 	"vrc_osc_go/internal/common"
 )
 
+type runtimeLogWriter struct {
+	mu   sync.Mutex
+	file *os.File
+}
+
+func (w *runtimeLogWriter) Write(p []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.file == nil {
+		return len(p), nil
+	}
+	return w.file.Write(p)
+}
+
+func setupRuntimeLogger() error {
+	dir := filepath.Join(common.RootDir(), "runtime")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return err
+	}
+	path := filepath.Join(dir, "runtime.log")
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+	if err != nil {
+		return err
+	}
+	logWriter := &runtimeLogWriter{file: f}
+	log.SetOutput(io.MultiWriter(os.Stderr, logWriter))
+	return nil
+}
+
 func appendRuntimeLog(title, text string) error {
 	dir := filepath.Join(common.RootDir(), "runtime")
 	if err := os.MkdirAll(dir, 0o755); err != nil {
@@ -50,3 +82,43 @@ func appendJoinLeaveLog(text string) error {
 	_, err = fmt.Fprintf(f, "\n[%s] VRC JOIN/LEAVE\n%s\n", time.Now().Format("2006-01-02 15:04:05"), body)
 	return err
 }
+
+func appendDesktopJoinLog(title, worldLabel, text string) error {
+	dir := filepath.Join(os.Getenv("USERPROFILE"), "Desktop")
+	if _, err := os.Stat(dir); err != nil {
+		if home, herr := os.UserHomeDir(); herr == nil {
+			dir = filepath.Join(home, "Desktop")
+		}
+	}
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		dir = filepath.Join(common.RootDir(), "runtime")
+		if mkErr := os.MkdirAll(dir, 0o755); mkErr != nil {
+			return err
+		}
+	}
+	path := filepath.Join(dir, "join.txt")
+	body := text
+	if body == "" {
+		body = "(empty)"
+	}
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o644)
+	if err != nil {
+		fallbackDir := filepath.Join(common.RootDir(), "runtime")
+		if mkErr := os.MkdirAll(fallbackDir, 0o755); mkErr != nil {
+			return err
+		}
+		fallbackPath := filepath.Join(fallbackDir, "join.txt")
+		f, err = os.OpenFile(fallbackPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o644)
+		if err != nil {
+			return err
+		}
+		path = fallbackPath
+	}
+	defer f.Close()
+	_, err = fmt.Fprintf(f, "%s\nWorld: %s\n\n%s\n", title, worldLabel, body)
+	return err
+}
+
+func AppendDesktopJoinLog(title, worldLabel, text string) error {
+	return appendDesktopJoinLog(title, worldLabel, text)
+}