#!/bin/bash
mailboxes="${HOME}/.mutt/mbsyncloop.mailboxes"

do_mbsync() { # (channel)
	echo -e "synchronising $1 ..."
	mbsync $1 && echo -e "... done" || echo -e "... failed"
}

get_mailboxes() { # (maildir)
	echo -n "mailboxes \"+\""
	find "$1" -type d -name cur | while read path; do
		mbox="$(basename $(dirname $path))"
		[[ $mbox == "."* ]] || continue
		mbox="+$mbox"
		echo -n " \"$mbox\""
	done
	echo ""
}

update_mailboxes() {
	mboxes="$(get_mailboxes "$1")"
	[[ -f $mailboxes ]] || {
		echo "initially creating $mailboxes"
		echo -n $mboxes > "$mailboxes"
		return
	}
	old_mboxes="$(<$mailboxes)"
	[[ "$mboxes" == "$old_mboxes" ]] || {
		echo "updating $mailboxes"
		echo -n $mboxes > "$mailboxes"
	}
}

imaphost="$(awk '/^Host /{print $2}' ~/.mbsyncrc)"

# sync INBOX every 10 seconds,
# sync subfolders every minute
cnt=0
while true; do
	ping -c 1 $imaphost >/dev/null 2>&1 || {
		echo "Host $imaphost not responding"
		sleep 10
		continue
	}
	do_mbsync inbox
	[[ $((cnt % 10)) -eq 0 ]] && {
		cnt=0
		do_mbsync folders
		update_mailboxes "${HOME}/.maildir"
	}
	((cnt++))
	sleep 10
done