Add log level system and sync logging

- log.go: log level system (DEBUG, INFO, WARN, ERROR, NONE)
- CLI: -log-level flag (default info), -verbose as shorthand for debug
- Watcher: logs sync/remove actions at INFO level
- Watcher: logs events at DEBUG level
- Errors: structured error messages (DISK FULL, PERMISSION DENIED, etc.)
- Updated README with -log-level flag

1 files changed, 19 insertions, 9 deletions

diff --git a/main.go b/main.go
index 077aec2..570890d 100644
--- a/main.go
+++ b/main.go
@@ -12,37 +12,47 @@ import (
 var (
 	hostDir  = flag.String("host", "/host", "Host source directory (read-only)")
 	dataDir  = flag.String("data", "/data", "Data destination directory")
-	verbose  = flag.Bool("verbose", false, "Enable verbose logging")
+	verbose  = flag.Bool("verbose", false, "Enable verbose logging (shorthand for -log-level debug)")
+	logLevel = flag.String("log-level", "info", "Log level: debug, info, warn, error, none")
 	dryRun   = flag.Bool("dry-run", false, "Preview what would be synced without copying")
 )
 
 func main() {
 	flag.Parse()
-	log.SetFlags(log.LstdFlags | log.Lshortfile)
 
 	if *verbose {
-		log.Println("sourcewatch starting...")
-		log.Printf("host: %s, data: %s, dry-run: %v", *hostDir, *dataDir, *dryRun)
+		*logLevel = "debug"
 	}
 
+	level, err := ParseLogLevel(*logLevel)
+	if err != nil {
+		log.Fatal(err)
+	}
+	SetLogLevel(level)
+
+	log.SetFlags(0)
+	log.SetOutput(nil)
+
 	stack := NewGitignoreStack(*hostDir)
 
 	manifest, err := initialSync(*hostDir, *dataDir, stack, *dryRun)
 	if err != nil {
-		log.Fatalf("initial sync failed: %v", err)
+		logErrorf("initial sync failed: %v", err)
+		os.Exit(1)
 	}
 
 	if *dryRun {
-		log.Println("dry-run complete, exiting")
+		logInfo("dry-run complete, exiting")
 		return
 	}
 
-	log.Println("watcher: ready, monitoring for changes ...")
+	logInfo("watcher: ready, monitoring for changes ...")
 
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer cancel()
 
-	if err := watch(ctx, *hostDir, *dataDir, manifest, stack, *dryRun, *verbose); err != nil {
-		log.Fatalf("watcher failed: %v", err)
+	if err := watch(ctx, *hostDir, *dataDir, manifest, stack, *dryRun); err != nil {
+		logErrorf("watcher failed: %v", err)
+		os.Exit(1)
 	}
 }