feat(PROJ-38): rethread — rückwirkendes Mail-Threading

cmd/archivmail/cmd_import.go

@@ -285,6 +285,7 @@ Commands:
   export         E-Mails exportieren (EML, MBOX)
   reindex        Index neu aufbauen (alle oder pro Mandant)
   recompress     Bestehende Mails nachträglich gzip-komprimieren
+  rethread       Thread-IDs rückwirkend aus In-Reply-To/References befüllen
   version        Version anzeigen
   help           Diese Hilfe anzeigen
 
@@ -327,5 +328,9 @@ archivmail reindex [flags]
 archivmail recompress [flags]
   --config     Pfad zur Konfigurationsdatei (Standard: /etc/archivmail/config.yml)
   --dry-run    Simulation: zeigt wie viel gespart würde, ohne Dateien zu ändern
+
+archivmail rethread [flags]
+  --config     Pfad zur Konfigurationsdatei (Standard: /etc/archivmail/config.yml)
+  --dry-run    Simulation: zeigt wie viele Mails gethreaded würden, ohne DB zu ändern
 `, AppVersion)
 }

cmd/archivmail/cmd_rethread.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log/slog"
+	"os"
+
+	"github.com/archivmail/config"
+	"github.com/archivmail/internal/storage"
+)
+
+// runRethread walks all emails without thread_id and sets thread relationships
+// by parsing In-Reply-To / References headers.
+//
+// Usage: archivmail rethread [--config path] [--dry-run]
+func runRethread(args []string) {
+	fset := flag.NewFlagSet("rethread", flag.ExitOnError)
+	configPath := fset.String("config", "/etc/archivmail/config.yml", "path to config file")
+	dryRun := fset.Bool("dry-run", false, "simulate without writing changes")
+	_ = fset.Parse(args)
+
+	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
+
+	cfg, err := config.Load(*configPath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: load config: %v\n", err)
+		os.Exit(1)
+	}
+
+	storeCfg := storage.Config{
+		Dir:             cfg.Storage.StorePath,
+		Keyfile:         cfg.Storage.Keyfile,
+		DSN:             cfg.Database.DSN(),
+		CompressEnabled: cfg.Storage.Compress,
+	}
+	mailStore, err := storage.New(storeCfg)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: storage init: %v\n", err)
+		os.Exit(1)
+	}
+	defer mailStore.Close()
+
+	if *dryRun {
+		logger.Info("rethread: DRY-RUN — keine Änderungen werden gespeichert")
+	}
+
+	stats, err := mailStore.Rethread(context.Background(), *dryRun, logger)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: rethread: %v\n", err)
+		os.Exit(1)
+	}
+
+	logger.Info("rethread: abgeschlossen",
+		"total", stats.Total,
+		"updated", stats.Updated,
+		"skipped", stats.Skipped,
+		"errors", stats.Errors,
+	)
+
+	if stats.Errors > 0 {
+		os.Exit(1)
+	}
+}

cmd/archivmail/main.go

@@ -60,6 +60,9 @@ func main() {
 		case "recompress":
 			runRecompress(os.Args[2:])
 			return
+		case "rethread":
+			runRethread(os.Args[2:])
+			return
 		case "version":
 			fmt.Printf("archivmail %s\n", AppVersion)
 			for mod, ver := range Modules {