write code frame

main.go

@@ -0,0 +1,179 @@
+package main
+
+import (
+	"context"
+	"encoding/csv"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"time"
+
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v2"
+	bolt "go.etcd.io/bbolt"
+)
+
+func main() {
+	app := &cli.App{
+		Name:  "mail-migrator",
+		Usage: "Migrate IMAP mailboxes between servers",
+		Flags: []cli.Flag{
+			&cli.StringFlag{Name: "src", Usage: "Source IMAP URL (user:pass@host:port)"},
+			&cli.StringFlag{Name: "dst", Usage: "Destination IMAP URL (user:pass@host:port)"},
+			&cli.StringFlag{Name: "batch", Usage: "CSV file with src,dst entries for batch migration"},
+			&cli.BoolFlag{Name: "insecure", Usage: "Allow insecure TLS (trust self-signed certs)"},
+			&cli.BoolFlag{Name: "resume", Usage: "Resume incomplete migrations"},
+			&cli.StringFlag{Name: "state", Value: "state.db", Usage: "Path to state DB (Bolt)"},
+			&cli.StringFlag{Name: "log", Usage: "Path to log file (optional)"},
+		},
+		Action: func(c *cli.Context) error {
+			setupLogging(c.String("log"))
+			insecure := c.Bool("insecure")
+			resume := c.Bool("resume")
+			statePath := c.String("state")
+
+			if batch := c.String("batch"); batch != "" {
+				return runBatch(batch, insecure, resume, statePath)
+			}
+
+			src := c.String("src")
+			dst := c.String("dst")
+			if src == "" || dst == "" {
+				return fmt.Errorf("either src/dst or batch must be provided")
+			}
+			return migrateOne(context.Background(), src, dst, insecure, resume, statePath)
+		},
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		logrus.Fatal(err)
+	}
+}
+
+func setupLogging(file string) {
+	logrus.SetFormatter(&logrus.TextFormatter{FullTimestamp: true})
+	logrus.SetLevel(logrus.InfoLevel)
+	if file != "" {
+		f, err := os.OpenFile(file, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+		if err != nil {
+			log.Fatalf("unable to open log file: %v", err)
+		}
+		logrus.SetOutput(io.MultiWriter(os.Stdout, f))
+	}
+}
+
+func runBatch(path string, insecure, resume bool, statePath string) error {
+	f, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	reader := csv.NewReader(f)
+	for {
+		rec, err := reader.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		if len(rec) < 2 {
+			logrus.Warn("invalid record, skipping")
+			continue
+		}
+		src, dst := rec[0], rec[1]
+		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Minute)
+		if err := migrateOne(ctx, src, dst, insecure, resume, statePath); err != nil {
+			logrus.Errorf("migration failed for %s -> %s: %v", src, dst, err)
+		}
+		cancel()
+	}
+	return nil
+}
+
+// migrateOne performs migration for single account
+func migrateOne(ctx context.Context, src, dst string, insecure, resume bool, statePath string) error {
+	logrus.Infof("Starting migration %s -> %s (insecure=%v, resume=%v)", src, dst, insecure, resume)
+
+	// Parse IMAP URLs
+	srcCfg, err := parseIMAPURL(src)
+	if err != nil {
+		return fmt.Errorf("parse source URL: %w", err)
+	}
+
+	dstCfg, err := parseIMAPURL(dst)
+	if err != nil {
+		return fmt.Errorf("parse destination URL: %w", err)
+	}
+
+	// Open state database if resume is enabled
+	var db *bolt.DB
+	if resume {
+		db, err = openStateDB(statePath)
+		if err != nil {
+			return fmt.Errorf("open state DB: %w", err)
+		}
+		defer db.Close()
+	}
+
+	// Connect to source
+	srcClient, err := connectIMAP(srcCfg, insecure)
+	if err != nil {
+		return fmt.Errorf("connect to source: %w", err)
+	}
+	defer srcClient.Logout()
+
+	// Connect to destination
+	dstClient, err := connectIMAP(dstCfg, insecure)
+	if err != nil {
+		return fmt.Errorf("connect to destination: %w", err)
+	}
+	defer dstClient.Close()
+
+	// List mailboxes from source
+	mailboxes, err := listMailboxes(srcClient)
+	if err != nil {
+		return fmt.Errorf("list mailboxes: %w", err)
+	}
+
+	logrus.Infof("Found %d mailboxes to migrate", len(mailboxes))
+
+	// Migrate each mailbox
+	for _, mbox := range mailboxes {
+		// Skip certain system mailboxes
+		if shouldSkipMailbox(mbox.Name) {
+			logrus.Debugf("Skipping mailbox: %s", mbox.Name)
+			continue
+		}
+
+		stateKey := formatStateKey(src, dst, mbox.Name)
+
+		logrus.Infof("Migrating mailbox: %s", mbox.Name)
+		if err := copyMessages(srcClient, dstClient, mbox.Name, mbox.Name, stateKey, db); err != nil {
+			logrus.Errorf("Failed to migrate mailbox %s: %v", mbox.Name, err)
+			continue
+		}
+	}
+
+	logrus.Infof("Migration completed successfully")
+	return nil
+}
+
+// shouldSkipMailbox determines if a mailbox should be skipped
+func shouldSkipMailbox(name string) bool {
+	// Skip common system/virtual mailboxes
+	skipList := []string{
+		"[Gmail]/All Mail",
+		"[Gmail]/Important",
+		"[Gmail]/Starred",
+		"[Gmail]/Chats",
+	}
+
+	for _, skip := range skipList {
+		if name == skip {
+			return true
+		}
+	}
+	return false
+}