func checkAndPurgeMessages(conn *imap.Client, requests chan WorkRequest, checkRequests chan checkExistsRequest, wg *sync.WaitGroup) {
defer wg.Done()
timeout := time.NewTicker(NoopMinutes * time.Minute)
done := false
for {
select {
case request, ok := <-requests:
if !ok {
done = true
break
}
// check and wait for response
response := make(chan bool)
cr := checkExistsRequest{UID: request.UID, MessageId: request.Value, Response: response}
checkRequests <- cr
// if response is false (does not exist), flag as Deleted
if exists := <-response; !exists {
log.Printf("not found in src. marking for deletion: %s", request.Value)
err := AddDeletedFlag(conn, request.UID)
if err != nil {
log.Printf("Problems removing message from dst: %s", err.Error())
}
}
case <-timeout.C:
imap.Wait(conn.Noop())
}
if done {
break
}
}
log.Printf("expunging...")
// expunge at the end
allMsgs, _ := imap.NewSeqSet("")
allMsgs.Add("1:*")
imap.Wait(conn.Expunge(allMsgs))
log.Printf("expunge complete.")
}