webmail: add export functionality

per mailbox, or for all mailboxes, in maildir/mbox format, in tar/tgz/zip
archive or without archive format for single mbox, single or recursive. the
webaccount already had an option to export all mailboxes, it now looks similar
to the webmail version.

ctl_test.go

@@ -306,8 +306,8 @@ func TestCtl(t *testing.T) {
 	})
 
 	// Export data, import it again
-	xcmdExport(true, []string{filepath.FromSlash("testdata/ctl/data/tmp/export/mbox/"), filepath.FromSlash("testdata/ctl/data/accounts/mjl")}, &cmd{log: pkglog})
-	xcmdExport(false, []string{filepath.FromSlash("testdata/ctl/data/tmp/export/maildir/"), filepath.FromSlash("testdata/ctl/data/accounts/mjl")}, &cmd{log: pkglog})
+	xcmdExport(true, false, []string{filepath.FromSlash("testdata/ctl/data/tmp/export/mbox/"), filepath.FromSlash("testdata/ctl/data/accounts/mjl")}, &cmd{log: pkglog})
+	xcmdExport(false, false, []string{filepath.FromSlash("testdata/ctl/data/tmp/export/maildir/"), filepath.FromSlash("testdata/ctl/data/accounts/mjl")}, &cmd{log: pkglog})
 	testctl(func(ctl *ctl) {
 		ctlcmdImport(ctl, true, "mjl", "inbox", filepath.FromSlash("testdata/ctl/data/tmp/export/mbox/Inbox.mbox"))
 	})

doc.go

@@ -51,8 +51,8 @@ any parameters. Followed by the help and usage information for each command.
 	mox queue webhook retired print id
 	mox import maildir accountname mailboxname maildir
 	mox import mbox accountname mailboxname mbox
-	mox export maildir dst-dir account-path [mailbox]
-	mox export mbox dst-dir account-path [mailbox]
+	mox export maildir [-single] dst-dir account-path [mailbox]
+	mox export mbox [-single] dst-dir account-path [mailbox]
 	mox localserve
 	mox help [command ...]
 	mox backup dest-dir
@@ -724,9 +724,11 @@ Export one or all mailboxes from an account in maildir format.
 Export bypasses a running mox instance. It opens the account mailbox/message
 database file directly. This may block if a running mox instance also has the
 database open, e.g. for IMAP connections. To export from a running instance, use
-the accounts web page.
+the accounts web page or webmail.
 
-	usage: mox export maildir dst-dir account-path [mailbox]
+	usage: mox export maildir [-single] dst-dir account-path [mailbox]
+	  -single
+	    	export single mailbox, without any children. disabled if mailbox isn't specified.
 
 # mox export mbox
 
@@ -737,13 +739,15 @@ Using mbox is not recommended. Maildir is a better format.
 Export bypasses a running mox instance. It opens the account mailbox/message
 database file directly. This may block if a running mox instance also has the
 database open, e.g. for IMAP connections. To export from a running instance, use
-the accounts web page.
+the accounts web page or webmail.
 
 For mbox export, "mboxrd" is used where message lines starting with the magic
 "From " string are escaped by prepending a >. All ">*From " are escaped,
 otherwise reconstructing the original could lose a ">".
 
-	usage: mox export mbox dst-dir account-path [mailbox]
+	usage: mox export mbox [-single] dst-dir account-path [mailbox]
+	  -single
+	    	export single mailbox, without any children. disabled if mailbox isn't specified.
 
 # mox localserve
 

export.go

@@ -12,38 +12,42 @@ import (
 )
 
 func cmdExportMaildir(c *cmd) {
-	c.params = "dst-dir account-path [mailbox]"
+	c.params = "[-single] dst-dir account-path [mailbox]"
 	c.help = `Export one or all mailboxes from an account in maildir format.
 
 Export bypasses a running mox instance. It opens the account mailbox/message
 database file directly. This may block if a running mox instance also has the
 database open, e.g. for IMAP connections. To export from a running instance, use
-the accounts web page.
+the accounts web page or webmail.
 `
+	var single bool
+	c.flag.BoolVar(&single, "single", false, "export single mailbox, without any children. disabled if mailbox isn't specified.")
 	args := c.Parse()
-	xcmdExport(false, args, c)
+	xcmdExport(false, single, args, c)
 }
 
 func cmdExportMbox(c *cmd) {
-	c.params = "dst-dir account-path [mailbox]"
+	c.params = "[-single] dst-dir account-path [mailbox]"
 	c.help = `Export messages from one or all mailboxes in an account in mbox format.
 
 Using mbox is not recommended. Maildir is a better format.
 
 Export bypasses a running mox instance. It opens the account mailbox/message
 database file directly. This may block if a running mox instance also has the
 database open, e.g. for IMAP connections. To export from a running instance, use
-the accounts web page.
+the accounts web page or webmail.
 
 For mbox export, "mboxrd" is used where message lines starting with the magic
 "From " string are escaped by prepending a >. All ">*From " are escaped,
 otherwise reconstructing the original could lose a ">".
 `
+	var single bool
+	c.flag.BoolVar(&single, "single", false, "export single mailbox, without any children. disabled if mailbox isn't specified.")
 	args := c.Parse()
-	xcmdExport(true, args, c)
+	xcmdExport(true, single, args, c)
 }
 
-func xcmdExport(mbox bool, args []string, c *cmd) {
+func xcmdExport(mbox, single bool, args []string, c *cmd) {
 	if len(args) != 2 && len(args) != 3 {
 		c.Usage()
 	}
@@ -53,6 +57,8 @@ func xcmdExport(mbox bool, args []string, c *cmd) {
 	var mailbox string
 	if len(args) == 3 {
 		mailbox = args[2]
+	} else {
+		single = false
 	}
 
 	dbpath := filepath.Join(accountDir, "index.db")
@@ -65,7 +71,7 @@ func xcmdExport(mbox bool, args []string, c *cmd) {
 	}()
 
 	a := store.DirArchiver{Dir: dst}
-	err = store.ExportMessages(context.Background(), c.log, db, accountDir, a, !mbox, mailbox)
+	err = store.ExportMessages(context.Background(), c.log, db, accountDir, a, !mbox, mailbox, !single)
 	xcheckf(err, "exporting messages")
 	err = a.Close()
 	xcheckf(err, "closing archiver")